Brevard Contractors School - Understanding Construction Drawings

Brevard Contractors School
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Day 2 Exam Review
The following summary is the basic process to follow in doing a construction job. This is
also the layout of the CSI format, and of Walker's Estimating Guide.
Understanding and Reading Plans
This section details how working drawings are developed. The first drawings tend to be
schematic drawings, these are conceptual drawings. The next phase are preliminary
drawings, they provide a graphic view of the project, refined detail or look and feel,
showing elevations and deign themes.
Preparing working drawings represents the final step in the design process. The
drawings are called a set. Working drawings should be in accordance with the building
code, and other agency requirements.
There are a number of particular drawings. A set of drawings might include architectural
drawings; structural drawings; mechanical drawings; electrical drawings; and site plans.
Site Plans show the building on the property, as well as utilities and sewer connections,
and storm water retention.

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• Architectural drawings show layout, floor plans, and elevations.
• Structural drawings, show structural load bearing systems.
• Mechanical drawings, show plumbing, HVAC, and fire protection.
• Electrical drawings showing power and lighting.
A set of drawings will often have instructions written by the architect called
specifications. If the project is small the specifications will be printed on the plans.
The Cover Sheet has essential information, it has most of the information required by the
estimator and foreman who builds the project. It also has basic information concerning
the project, the site, the architect, builder, owner(s), and consultants.
The cover sheet lists all the other drawings in order. The cover sheet lists specific
requirements of the building code that apply to this design, the type of construction, the
zoning use, as well as abbreviations, symbols, and notes.
After the working drawings are finished often Revisions are necessary for clarification.
Small modifications are shown on a revision sheet, but major changes require a new
drawing. Remember that revisions usually cause change orders, which must be in
writing, agreed upon and signed by all parties. Revisions are denoted on a drawing by a
circled area that looks like a scalloped cloud. The revision marker is a triangle with the
revision number.
Conventions used on drawings:
Most drawings for building construction are based on orthographic projection,
which is a parallel projection to a plane by lines perpendicular to the plane. In this way,
all dimensions will be true. Two other types of drawings are used isometric and cabinet
projections. Isometrics are drawings in which all horizontal and vertical lines have a true
length (Walker Chapter 1).

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The Title Block is located in the bottom right hand corner, or the right panel. The title
architect to seal the drawings, list his/her registration number, and sign the drawings.
Naturally, drawings use minimal words but rather rely on lines and symbols to inform.
The common lines are the main object line that defines the outline of the structure.
Dimension lines typically have arrowheads and are measurement lines. Extension lines
are used with dimension lines to show distance. Hidden lines are dash lines, and show
lines that are hidden under or behind other parts of the structure. Center lines show the
center of the structure or object and have a large C printed over an L. Center line
calculations allow for the proper takeoff of block or brick materials in construction. If CL
is given on the plans then you can determine materials needed directly from the
dimensions on the plans.
The formula for calculation CL is to add 4 times the thickness of the work to the
inside dimensions OR subtract 4 times the thickness of the work (when viewed from
the top) from the outside dimensions. If the block is 8" thick multiply 4 corners * 8" =
32". If you were given outside dimensions subtract -32" if you were given inside
dimensions add +32". A building may have many inside and outside corners, but they
cancel each other out, leaving only 4 corners that could be over or under counted,
therefore you multiply the wall thickness by 4 corners.
Common wall dimensions
Wall thickness +- dimension
4" 4 * 4" = 16" +-
6" 4 * 6" = 24" +-
8" 4 * 8" = 32" +-
Graphic symbols as included in Chapter 1 of Walkers provide the reader with a standard
form of recognizing information. Abbreviations are used to save time and space, they
are listed in Chapter 1 of Walkers following the symbols. The symbols and abbreviations
are incorporated in a chart or table called the Legend.
The architects ruler or scale is a three sided ruler with 1/8" scale, 1/4" scale, 1" scale, 1/2"
scale, 3/4" scale, 3/8 inch scale, 3/16 inch scale, 3/32 inch scale, 11/2 inch scale, and 3
inch scale. Some drawings will use different scales for different sections of the drawing.
The walls may be 1/4" while the floor might be 1/8", and the electrical 1".
Commercial plans typically include a site plan while this is not always true for house
plans, as the site may not have been selected when the drawings were made.

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The main purpose of the site plan is to locate the building within the confines of the
building lot. This is important to locate the property within the zoning setback
requirements. Setback dimensions are shown in feet and 100th
of feet, (not inches).
A registered land surveyor performs a site survey. An additional use of the survey and
site plan is to show the topography of the property. The changes in surface elevation are
shown by contour lines. The reference point is called a datum. Contour lines are
typically shown in 5-foot elevation increments, but may be in 1-foot increments.
Contours are continuous and do not merge together.
A known elevation on the site used as a reference point during construction is called
a benchmark BM. A benchmark is a point of known elevation, established by registered
survey and marked by a brass plate on a post at or near ground level by a brass plug
(PPHC, 18). The benchmark is established in relation to the datum. When elevations are
required on the project the term grades is used rather than contours. Contours are given
in single numbers, while grades have 2 decimal places of accuracy. The North Arrow
clearly shows the buildings orientation on the property. The surveyor will also use
compass directions to define the property boundaries; these compass directions are called
bearings of a line.
Transit Level
The instrument used to obtain elevations is a builder’s level, a transit level, or a
transit, which is also called a Theodolite. A Target is a rod with a ruler graduation scale
and is used for measuring to find the difference in grade or elevation between two points.
The difference between the rod readings at two locations will be the difference in
elevation or grade. A LOS or line of site is the line of site from the cross hairs in the
builders level to a point viewed on the target. The Station is a point you are working

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from, or a point you are trying to establish or verify. The point where the level is located
is a station, as well as the point where the assistant holds the target rod. Station
Elevation S.E. is a point above the reference point typically the benchmark. The SE may
be expressed in height above sea level or +-BM.
The Benchmark BM is a station of known elevation and is expressed in terms of
feet above sea level. The Backsight BS is the rod measurement obtained by the line of
sight. The reading when the rod is held on a given benchmark or station elevation. The
height of the instrument or HI is the height of the line of sight (LOS) above the
benchmark elevation. The foresight FS is the rod measurement obtained by the lie of
sight. The reading when the rod is held on a station to be established or verified. Station
spacing is used for laying long pipe sections. The first section is always station 0+00 and
the next station is 0+50, meaning it is 50 feet from the first station. Station 1+00 is 100
feet away from the starting point, while station 2+00 is 200 feet away, and station 3+00 is
300 feet away from the starting point.
Station Elevation Formula: BM + BS = HI – FS = Station Elevation
Foresight Reading Formula: BM + BS = HI – SE = Foresight Reading
Taking a transit level reading (refer to PPCC)
• Set up the instrument at a convenient point between the benchmark and the
unknown elevation, where the rod (held on the bench mark) will be in sight. Level
the instrument.
• Take a sight on the rod and record the reading. This is called a Backsight. This
reading, added to the benchmark elevation is the H.I. (height of the instrument).
• Have the rod moved to a convenient location between the instrument and the
unknown elevation. Swivel the instrument around so that a reading can be taken
on the rod at its new location. This is foresight. Record that reading and subtract it
form the H.I. The result is the elevation of the point on which the rod rests, or
Station 1.
• Now move the instrument to a new position between Station 1 and the unknown
elevation and take a Backsight. Add that Backsight reading to the elevation of
Station 1 and you have a new H.I.
• Have the rod moved to a new station and take a foresight. From it establish the
elevation of Station 2.
• This procedure is repeated until the final Station reaches the unknown elevation.
Note: That residential and building contractors are required to use a registered
professional, while the general contractor can do site survey work him/herself. In any
case the boundaries of the lot on which a building is to be constructed should be
established by markers, called monuments, set by a registered surveyor (PPHC, 34).

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Commercial property is required to have water retention areas, but it has become
commonplace for even houses to be required to handle storm water on the property,
therefore water retention areas called drainage and utility plans are often required. The
elevation of a pipe is given with respect to its invert. Invert of a pipe is the bottom of the
pipe trough through which the liquid water/sewer flows.
Site improvement plans include curbing, walks, retaining walls, paving, fences, and
steps.
Architectural drawings are numbered with an A for architect, and given in order;
• Basement
• Ground floor plans
• Upper-level floor plans
• Roof
• Exterior elevations, sections
• Interior elevations
• Details
• Windows and doors
• Finish schedules
The plan view is typically a floor plan drawn by an architect to show how the space will
be used. Floor plans show the major features of the building, such as windows, doors,
interior rooms, partitions, and built in cabinetry and bookcases. Architectural plans
typically include notes that further define the work. Schedules are easy to read individual
tables which list items like all the windows to be used in the structure, how each room is
to be finished, all the lighting fixtures, all the bathroom and kitchen fixtures, as well as
trusses.
Structural drawings provide a view of the structural members and how they will
support loads and transmit these loads to the ground. The letter S prefixes structural
drawings. Mechanical Drawings can be plumbing, HVAC, or fire protection. The letter
P prefixes plumbing drawings, while H prefixes HVAC systems, and FP prefixes fire
protection drawings. The letter E prefixes electrical drawings.
It is essential that the contractor become familiar with the working drawings prior to the
site inspection and quantity takeoff. Look for mistakes and omissions when reviewing
the plans and make a decision if you even want to bid the job.
NOTE: It is worthwhile to buy Construction Master IV or V calculator on E-
bay or at Home Depot. Also, the mensuration section of Walker's has a lot of useful
formulas that you need to be familiar with prior to the exam. During the exam the
formula's you need can be found in Walkers or Principles and Practices of Commercial
Construction.

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Math calculations
for the exam.
All the math formulas which follow are available in Walkers Chapter 24.
Feet multiplied by feet become square feet.
Yards multiplied by yards become square yards.
Converting inches to decimal:
inches / 12 = decimal
e.g. 3"/12 = .25 or 25% of a foot
Converting decimal to inches:
Decimal * 12" = inches and decimal parts of an inch
Decimal parts of an inch * 16th
= number of 16th
parts of an inch
Area of a square or rectangle:
Area = length * width
A= l * w
Volume = length * width * depth
Cubic yards = volume / 27
Area of a trapezoid:
Area = length 1 + length 2 / 2
Area = Center Line length (middle) * height
Volume = area * depth
Area of a triangle:
Area = base * altitude * 1/2
A = 1/2 * b * a
Volume = area * depth

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Area of a right triangle:
Framers and contractors to square up work use the right triangle or "3-4-5 triangle". The
right triangle law or Pythagorean Theorem states that the square of the hypotenuse (long
side) of the right triangle is equal to the sum of the squares of the other two sides.
C
C2
= A2
+ B2
A2
= C2
– B2
A
B2
= C2
– A2
B
Drop, Run and Grade problems:
Grade % = Drop / Run * 100
Drop = Run / Grade
Run = Drop / Grade
Area of a Circle:
Area = ΠR2
Area = 3.14 * (radius * radius)
Volume = Area * Depth
Circumference = ΠD or 2ΠR
Area of a corner:
Area of an inside corner is 78.5%
Area = R2
* .785
Area of an outside corner is 21.5%
Area = R2
* .215
Notice that 78.5% (the inside corner) and 21.5% (the outside corner) add up to 100%. If
you remember 21.5% or 78.5% it is easy to subtract it from 100 and get the other number.
You need to know this for doing take off problems on day 2 of the exam.

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CSI Format Specifications:
All working drawings are issued with a set of specifications. The spec's as they are
called ideally cover every item or segment of work shown on the working drawings. The
spec's serve as a guideline for bidding and performing the work. The most widely used
system for arranging spec's is the CSI Master Format. The CSI format uses four major
categories in presenting information, which are further divided into 16 divisions;
• Bidding Requirements
• Contract Forms
• General Conditions
• Specifications (Technical)
•
The Spec's Divisions are:
Division 1 – General Requirements
Division 2 – Site Work
Division 3 – Concrete
Division 4 – Masonry
Division 5 – Metals
Division 6 – Woods and Plastics
Division 7 – Thermal and Moisture Protection
Division 8 – Doors and windows
Division 9 – Finishes
Division 10 – Specialties
Division 11 – Equipment
Division 12 – Furnishings
Division 13 – Special Construction
Division 14 – conveying systems
Division 15 – Mechanical Systems
Division 16 – Electrical Systems

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Bidding Requirements:
Bidding begins with an invitation for bid, or request for proposals (RFP) or
advertisement for bid. It clearly defines the date, time, and location for bids to be
submitted. The RFP will define the eligibility criteria to limit bidding, and define the
bond requirements.
The AIA contract forms previously discussed in the AIA summary sheet have the
following additions to the 14 basic articles found in AIA form A201. Technical
specifications deal with the actual products to be used. Addenda are any changes to the
contract documents. Alternates are changes in materials, methods of construction, or
additions or subtractions of the work. Allowances include items that were yet to be
finalized when the contract was being drafted. Unit prices are used when the exact cost
can not readily be determined.

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Project Management
Estimating and bidding:
The estimating and bidding process uses plans and specifications (the specs) and matches
them to available company personnel to determine the quantities of materials, labor, and
sub-contract labor that will be required to properly bid a contract.
The project contract is bid from the plans and specifications (the specs). They must be
followed exactly, as any deviation from the plans and specifications will be the
responsibility or the contractor, and he or she may (will likely) be responsible for paying
to make any corrections.
The specifications (specs) are a book of rules governing all of the material to be used and
the work to be performed on a construction project. "Specifications are the guiding
document an take precedence over the plans or other project documents (10-9)." When
differences exist between the plans and specifications, this should be discussed between
the owner and the contractor, and the outcome of these discussions should be put in
writing, and signed or initialed by all parties to the contract; owner, builder, and architect.
The Construction Specifications Institute (CSI) Master Format described in Walkers is
considered the industry standard numbering classification for bid packages. The CSI
Master Format is published by the American Institute of Architects (AIA), and can be
purchased through Building News Publishing (BNI).

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General Clauses and Conditions of the Master Format:
The general clauses and conditions of the Master Format specifies the legal requirements
of the project.
• Notice to Bidders
• Schedule of Drawings
• Instruction to Bidders
• Proposal
• Agreement
• General Conditions
Notice to Bidders:
The notice describes the project, its physical location, the time and place of the bid
opening, and where and how the plans and specifications can be obtained.
Schedule of Drawings:
The drawings schedule is a list, by number and title, of all the drawings related to the
project.
Instructions to Bidders:
This sections provides a brief description of the project, location, and how the job is to be
bid, either lump sum, one contract, or separate contracts for the various construction
trades (plumbing, heating, electrical, pool).
Proposal:
The proposal is a form made by the contractor which is a legal instrument that binds the
contractor to the owner IF:
• The contractor completes the proposal properly
• The contractor does not forfeit the bid bond
• The owner accepts the proposal
• The owner signs the agreement
The proposal may show or call for alternate bids, the project manager consults with the
contractor to determine which alternate bids have been accepted…

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Agreement:
The owner and contractor sign the agreement and the result is a legally binding contract.
General Conditions:
This section details general clauses included under the CSI Master Format. They include
general notes; definitions; contract documents; insurance; workmanship and materials;
substitutions; shop drawings; payments; coordination of work; corrections to work;
guarantee; compliance with all the laws and regulations; others circumstances worth
noting.
The conditions under the general conditions are not procedural, all have equal weight in
the document. Therefore, "everyone involved must study each item before taking a
position and assuming any responsibilities with respect to the project"(10-14).
According to the CSI Master Format, the contractor must use qualified individuals for the
site work, such as land surveyor or engineer.
The contractor must be careful, as any utilities damaged while digging are the responsibly
of the contractor.
The contractor must maintain an office on the site, and maybe required to provide a
telephone at the job site. Temporary toilet facilities, temporary light and power,
temporary heating (if necessary) are to be provided by the contractor.
The contractor agrees to replace faulty equipment and correct construction errors for a
period of one year.
Estimating:
• Planning is the process of determining requirements and devising and developing
methods and schemes of action for the construction of a project. Planning is a
combination of activity necessary, materials, equipment, and manpower estimates,
site layout, material delivery and storage, work schedules, quality control,
specialty tools, environmental protection, safety, and progress control (10-15).
• Estimating is the process of determining the amount and type of work to be
performed and the quantities of materials, labor and equipment needed.

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Methods of Estimating:
• Square foot method is based on a cost per square foot.
• Detailed survey of piece method consists of listing all materials and labor needed
for a project.
• Unit price method determine the cost of each unit of construction, such as
concrete slab, form work, doors, walls, just as in the piece method.
• Approximate estimates is less detailed and is based on deriving project costs
from previous projects. This approach is often used in combination with the
square foot method.
Types of Estimates:
• Preliminary Estimates establishes costs for budget purposes and to identify
general manpower requirements.
• Detailed Estimates is a precise statement of quantities for materials, equipment,
and manpower required to construct a given project.
• Activity Estimates lists all the steps necessary to construct a given project.
• Material Estimates lists of materials and quantities required to construct a given
project.
• Equipment Estimates lists the equipment, time, and number of pieces necessary to
construct a given project.
• Manpower Estimates estimate of direct labor man-days required to complete the
various activities of a specific project.
Estimating Guidelines:
• Use pre-printed or columnar forms and record phone numbers too.
• Use only the front side of each paper or form.
• Be consistent in listing dimensions.
• Used printed dimensions where given.
• Add up multiple printed dimensions.
• Use each set of dimensions to calculate related quantities.
• Convert foot and inch measurements to decimal
• Do not round off quantities.
• When doing "take offs" mark drawings with different colors.
• Group similar items together.
• Identify location and drawing numbers.
• Measure and list everything on the drawings.
• Add items not specifically listed, but necessary to complete the job.
• NOTE NTS – Not To Scale – look for NTS on exam.
• Develop a method for making an estimate.

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• List all gross dimensions that can or will be used again.
• Utilize design symmetry or repetition.
• Do not convert units until you make a total.
• Change orders and alterations: figure the total basic system, and then figure the
alterations and subtract them from the basic system, to avoid the confusion of
using negative numbers.
Estimating Controls:
• Use a pre-printed summary sheet and check to see that all items have been
calculated.
• Use a rule-of-thumb check to make a rough estimate. If a significant difference
exists between the rule-of-thumb checks and the total amount of the bid, the bid
should be re-checked and the estimators should be required to justify any
significant deviations from the rough estimate.
Labor Estimating Tables:
There is a complete book of labor estimating tables which can be purchased from the
CSI.
Construction Contracts:
If a conflict exists between the drawings and the specification, it is usual that the
specifications control.
Should a construction requirement appear only in the specifications and not on the
drawings, or vice versa, the contractor must provide the requirement just as though it
were included in both places (10-45).
Critical Path Method:
Critical path is covered in Walkers Chapter 1, as well as in the Contractors Manual
Chapter 10. This is an important part of the contractor’s exam, and you need to know
how to do a forward pass and a backward pass through the flow chart to determine
earliest finish date, and latest start date.
The principal objective of construction scheduling is to efficiently manage the
resources used in the construction process (Walkers 1.1__).
Sequential activities require that one activity be substantially complete before the next
one begins (Walker 1.132). Simultaneous activities are activities that are not critical nor
directly dependent on a critical activity, that is to say they can be completed within the

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time frame of a critical activity. Calculate an accurate duration for each activity. The
highest sum of activity durations that form a continuous chain of sequential activities
through the planned project, allowing contingency time for weather and other delaying
factors, is the scheduled duration of the entire project (Walker 1.1__).
Planning:
Planning is the most time consuming and critical element of the construction schedule
process.
The principal considerations of the CPM planning process involves a detailed breakdown
of work items.
• Activity: Responsibility to subcontract work
• Activity: Craft/Crew Requirements
• Activity: Material Requirements
• Activity: Equipment Requirements
• Location of Work
• Subdivisions of Work
• Cost Control Breakdown (Walker 1.134).
Network diagrams (CPM and Pert) are best at describing the interrelationship of
individual project activities (Walker 1.137).
The time duration required to complete an individual construction activity is based on the
amount of work required and the productivity of the labor and equipment to be used.
Example:
Masonry Walls to SOG (slab on grade) 4 days
Masonry Walls to Joist Bearing Activity 12 days
Top Masonry Wall Activity 2 days.
These activities are critical, that is, they are on the critical part of activities that must be
completed in sequence and on time in order for the project to finish on schedule (Walker
1.141). In this example the three nodes have duration of 4 + 12 + 2 = 18 days, which
would represent the early, finish (EF) of these three activity nodes.

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0 4 4 16 16 18
ACTIVITY NODE
ES EF (ES and EF numbers derived during forward pass)
LS LF/Float (LS and LF numbers derived during backward pass)
D = duration time of activity #
ES = early start time activity #
EF = early finish time activity #
LS = late start time activity #
LF = late finish time activity #
FS = finish to start constraint between 2 activities (wait time)
SS = start to start constraint between 2 activities (wait time)
FF = finish to finish constraint between 2 activities (wait time)
On the test you will be given a flow chart that has activities, durations of events, and
an early start date for each event. You will be required to calculate the time it will take to
perform all the critical activities, and then you will be required to do a backward pass and
calculate the late start date for each activity.
The early start (ES) date of an activity is the earliest time the activity can possibly
start, allowing for the time required to complete preceding activities. The early finish
(EF) date of an activity is the very latest it can finish and still allow the project to be
completed by a designated time or date. The late start (LS) date of an activity is the
latest possible time that it can be started and still allow the targeted completion date of
the project to be met; the late start (LS) is obtained by subtracting the activity's duration
from its late finish (LF) time.
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The Forward Pass:
Early start and early finish proceed from left to right. Each activity starts just as
soon as the last of its predecessor activities is finished. Each activity has its own activity
box. The ES of each activity is calculated first. The EF is then obtained by adding the
activity duration to its ES value; the EF is recorded in the upper right corner of the
activity box. (Walker 1.144).
Merge Activities:
The rule for Merge Activities on the forward pass is that its earliest possible start time is
equal to the latest (or largest) EF value of the activities immediately preceding it (Walker
1.1__).
The Backward Pass:
In the backward pass you calculate the late start (LS) date and the late finish (LF)
for each activity. Each activity must finish as late as possible without delaying project
completion (Walker 1.1__).
The rule for Burst Activities, which are more than one activity following them, is that
the LF value for a Burst Activity is equal to the earliest (smallest) LS for the activities
that follow it (Walker 1.1__).
Float is time leeway that exists in the schedule of some activities but not in others.
There are two types of float.
Total Float for an activity is obtained by subtracting its ES form its LS time. Free
Float of an activity is found by subtracting its early finish time from the earliest start time
of the activity or activities that directly follow it. Free Float is the amount of time an
activity can be delayed without affecting the early start of the following activity.
Zero Float is called the Critical Path of the schedule network. The significance of
float is that it indicates the degree to which an activity is critical, how much delay this
activity can absorb without delaying the entire project.

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Pert Computations:
Pert uses three separate estimations for the duration of each activity.
• Optimistic Activity Duration
• Probable Activity Duration
• Pessimistic Activity Duration
Milestone Schedules:
A milestone schedule lists the dates anticipated for the start or completion of key and
critical project activities and work sequences as a measurement of project progress.
To recover and get back on schedule:
• Increase manpower or crews
• Add more crews
• Add more equipment
• Work overtime – extra hours or days
• Work multiple shifts (Walker 1.151)

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Site Work
Most site work is shown on civil drawings. The contractor will use the site-grading plan
to determine the quantities of cut and fill. It is often not possible to tell the exact nature of
the soil, so a geographic engineer will be hired to test the soil. There are many methods to
determine the content and nature of the soil. The most common is the test pit. The test pit
allows for a visual inspection of soil contents, stratification, water table height, and
cohesiveness. A common method for larger construction projects is test boring, which
provides a sample of the soil at extended depths. At this point a perk test is done to
determine how quickly water will be absorbed into the ground. The site is then cleared
and grubbed.
Clearing refers to removing brush, trees, and topsoil, while grubbing refers to
removing stumps. Topsoil is removed from the structure site and stockpiled on site for
reuse in lawn areas. Clearing work is calculated by multiplying the area by the depth that
must be maneuvered. The work is calculated in cubic yards, and is often bid in unit price
per cubic yard.
Demolition typically defines moving any existing structures or parts of structures.
Demolition can be very labor intensive, this is the main reason remodeling costs more
than comparable new construction. Demolition estimates should include labor,
machinery, hauling and dumpsite impact fees.
Demolition work is often bid in a lump sum LS due to the variety of tasks that are
performed.
Excavation is simply digging a hole for some purpose, such as erecting a building, or
laying a water or sewer pipe. Bulk excavation means moving large amounts of soil
around to establish a desired grade. A commonly method used for bulk excavation is
cross-sectional method. The cross-sectional method divides the area into a gird of small
equal sized squares, rectangles, and triangles (Walker's Ch 2). It is the easiest and most
frequently used methods of computing grading cuts and fills when the plot plans shows
both original and proposed contours. The contractor then tabulates how much cutting and
filling will need to be done to meet grade. The volume of soil moved in each square is
tabulated. When soil is excavated it tends to swell and increase in volume. Swell is
expressed as a percentage OVER the original volume. When earth is compacted it tends
to be compressed, and is expressed as a percentage of the original volume.

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27 CY with a 18% swell = 27 * 1.18 = 31.86 CY.
What was the original volume of 27 CY compacted 80%?
27/80 = .3375*100 = 33.75 CY.
The logic is that 27 CY = 80% so divide 27 /80 = a factor or percentage * 100% =
original volume. You can also cross multiply
27 * X = 2700 / 80 = 33.75
80 100
Excavation is a volume calculation. Excavation is calculated by length * width * height =
cubic feet / 27 = cubic yards. This holds true for excavations where only two sides of a
trench or hole are being excavated. If all four sides must have an angle of repose, then
you use the volume calculations for a trapezoid rather than a rectangle.
If you are trying to calculate how much soil needs to be hauled in or removed. It is
possible to take the four elevations from the site survey or site plan and average them and
subtract the average elevation from the desired elevation and multiply by length times
width and divide by 27 to yield an answer in cubic yards.
Builders Level
EL1 + EL2 + EL3 + EL4 / 4 = Average Elevation (A-EL)
Volume = (Final elevation – average elevation) *L * W:
Problem:
L = 100; W = 100; EL1 = +5.1; EL2 = +3.0; EL3 = +7.0; EL4 = -4.0; F-EL = +1.5
The problem would be solved as follows:
5.1+3+7-4 = 11.10 / 4 = 2.775 average elevation (A-EL)
+1.5 (final elevation) – 2.78 (average elevation)= -1.28 (average elevation) * 100' length
* 100 foot width = -12,800 / 27 = -474 CY of soil that must be removed to meet grade.

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In order to stabilize a trench in sand, gravel or wet clay it is necessary to slope the sides
in what is called an angle of repose. The more cohesive the soil, the steeper the angle of
repose can be.
Typical Angles of Repose
90° 0
63° 1/2:1
53° 3/4:1
45° 1:1
33° 11/2:1
26° 2:1
As mentioned earlier, if the excavation only requires 2 sides to be sloped then you
use the math formula for volume for a rectangle and a triangle. If all four sides are sloped
then you must use the volume formula for a trapezoid and add for one missed corner.
The formula for a trapezoid is:
Area = Length 1 + Length 2 / 2
OR Area = center line length (middle) * height
Volume = area * depth (H)
Missing corner = B*B*H/3, where B is the width of the slope and H is the height or depth
of the excavation.
So the total formula for calculating a 4 sided excavation is
Volume CY = (2*(Length 1 + Length 2 / 2) + 2*(Width 1 + Width 2 / 2) * H +1 missing
corner (B * B * H /3)) / 27
Option 2 from Walker's is:
Base Excavation: Length * Width * Height = area of a rectangle.
Area of side slope: Area of triangle = (base * height) / 2; multiplied by 4 sides, plus 4
corners (B * B * H) /27 = Volume CY
(Walker's Chapter 2)

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In cases where the soil cannot support a structure, it is often necessary to install Caissons.
Caissons can be dug as straight shafts or bell shaped at the bottom to increase load area.
The caisson carries through the unsatisfactory soil down to a material that can hold the
load (Walker's Ch 2).
Shoring is used when there is insufficient room to stabilize the slope (p81). Shoring can
be in the form of wood, steel, or concrete sheet piling.
Shoring is used when there is insufficient room to stabilize the slope (p81). Shoring can
be in the form of wood, steel, or concrete sheet piling.
Sheet Pile Shoring
1: Calculating amount of product needed for shoring an excavation using metal or wood.
2: Determine the perimeter or "girth" of the excavation. This will provide the number of
lineal feet required (Walker Ch. 2…). Add up all four sides to obtain lineal feet.
3: Are you using metal or lumber?
A: If using metal sheet pilings determine the product to be used? From the Table in
Chapter 2 of Walker's. For example; if we select MZ38 which is 18" inches wide and
divide the girth of the excavation by 1.5 feet (18 inches) this will tell you how many
pieces of metal sheet pilings you will need to buy. Now determine the length of sheet
metal that will be required. Usually one foot above grade on top and one to two feet will
be driven into the ground. On the exam they will either give you the total length required
or the excavation length and tell you or show you how much will be above grade and
how much will be driven into the ground. Take this amount and multiply by the total
number of pieces required to shore the excavation. If the question asks for it, determine
the weight of the steel sheet piling. The easiest way to do this is by multiplying the square
feet of the material used times the square foot weight in the table in Walker's 2.122.

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Example:
The basement is 100 feet by 57 feet and 8 feet deep, with one foot above grade and 1 foot
driven in the ground. Use MZ38 piling. 100+100+57+57= 314 ft / 1.5 feet (18 inches =
1.5 feet) 209.33 sheets of MZ38 10 feet long. 210 pieces * 10 feet length = 2,100 sq. ft. *
38 pounds per square foot = 79,800 pounds of steel sheet piling.
Board Feet Calculations
4: If you are using wood, then you have to change the dimensions from linear feet into
board feet. A board foot is a measure of quantity based on nominal dimensions equal to
144 sq. in, which equates to a board that is one foot square and one inch thick (FC, 4-5).
Lumber is commonly referred to by its nominal size, which at one time was the same as
the rough sawn measurement. The nominal width means you use the dimension of rough
sawn lumber such as 2"x4" or 2"x6", even if you are using dressed lumber. Dressed
lumber is lumber which has been surfaced in a planning machine to attain smoothness of
surface and uniformity of size (Formwork for Concrete, 4-3)." If it is planed on one side
it is called S1S, planed on one edge S1E, two sides S2S, or two edges S2E, and finally all
four sides is labeled S4S. S4S stands for surface 4 sides. Dressing or planning lumber
shaves about 1/4" off each dimension, on thinner pieces of wood only 1/8" is shaved off
each dimension. Therefore a dressed 2" x 4" will actually be 1 1/2" x 3 1/2" having lost
1/4" off each side. The table on page 4-4 of Formwork for Concrete provides common
timber sizes. In most applications of board foot measure (BFM) you use nominal
dimensions. In calculating board feet for shoring and forming you use actual width of the
board when determining the number of boards that will be required. If you are using
rough sawn lumber then use the nominal width when calculating the number of pilings
necessary. If you are using S4S then you use the actual width to calculate the number of
piling planks required. It is most common to use tongue and grove planks, as they are
easier to keep straight, and they hold water out. The top corners of the planks are cut off
to minimize splitting when they are being driven into the ground. The bottom edge of
each plank is angle cut to facilitate ground penetration. Using the table Lumber
Required for Sheet Piling in Walker's Chapter 2.116.
Table Calculation from Walker’s:
According to the table in Walker's 100 sq. ft. of area equals 220 b.f. of 2" x 8" T&G,
therefore 314' girth of the excavation * 10 ft. deep = 3,140 / 100 s.f. = 31.40 * 220 b.f. =
6,908 board feet. Or you can say 220 b.f. / 100 s.f. = 2.2: therefore 3,140 s.f. * 2.2 =
6,908 b.f.

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Board Foot formula:
BF = (t*w*l / 12) * number of planks
(t = thickness; w = width; l = length)
1 piling 2" * 8" * 10' / 12 = 13.33 board feet per plank
314' (diameter of excavation)* 12" = 3,768" (inches diameter of excavation)
3,768" / 7.25" (actual width of 8" board) = 519.72 or 520 boards T&G
520 * 13.33 board feet = 6,931.60 total board feet of lumber required.
Or
You can say 7.25" actual width of board / 12" = .604: 314' excavation / .604 = 519.86 or
520 boards T&G * 13.33 board feet per plank = 6,929.83 total board feet required.
So you understand that in using the formula you use nominal thickness and width *
length / 12 BUT you use girth or perimeter of excavation divided by the actual width
of the planks.
Board Feet Table:
If you are not shoring up the perimeter of the excavation, then you will, in all probability,
need to slope the sides of the excavation as per the OSHA safety rules, as described in the
previous section of this summary. After the work is complete then you will backfill the
sloped area and pack it down to a specified compaction level.

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Sheepsfoot Roller Problems
The sheepsfoot roller is a tractor drawn roller with numerous interlocking rubber tires. It
was used for compacting fill primarily.
Density specifications are usually called for in government work and for fills under
paving. Obtaining 95% compaction may take as many as 12 passes of a sheepsfoot roller
(Walker 2.74).
Solving this problem requires the table in Walkers chapter 2.74.
"Rate of Sheepsfoot Roller Compaction in Cubic Yards…"
The table makes the following assumptions:
• The number of passes of the roller will be between 1 and 12 (column 1).
• The materials are 70%, 80%, or 90% compactable (columns 2,3,4).
• The sheepsfoot roller is 5' feet wide.
• The roller operates at 2.5 mph (4 kph).
• The fill is in 12" inch thick layers.
• The job efficiency rate is 100%
• There is no loss time for maneuvering.
In the exam problem these seven factors may not be constant, so you will be required to
modify the table to solve the problem.
• The width of the sheepsfoot roller can be 5'__, 10'__, 15'__.
• The compaction rate of the fill is given for 70%, 80%, and 90%, but you may
need to calculate a higher or lower factor.
• If the fill is being laid in less than 12" inch deep layers, you must adjust the cubic
yards that are being compressed. The table assumes 12" deep layers, but if the fill

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is 6" inches deep then multiply by .50 (50%). If the layer is 9" inches deep then
multiply by .75 (75%).
• Job efficiency rate in the table is 100%, or no adjustment. An efficiency rate
varies between a 50 minutes work hour or 83% (.83) and a 45 minute work hour
or 75% (.75) . This becomes a factor by which you reduce the table answer.
• Maneuvering or turning also costs time, it is yet another factor that you must
deduct from the table answer. A job loss rate can vary from 5% to 10%, therefore
you would multiply the table answer by .95 or .90 (working time – loss = factor).
Problem:
A contractor is compacting 10,000 cubic yards of loam in 6" lifts. She is using a 10 foot
wide sheepsfoot roller moving at 2.5 mph. There will be 6 passes at 90% efficiency and
5% loss in time due to maneuvering. The time required to compact the loam is ______
hours?
Example
10,000 cubic yards
6" inch lifts
Loam = (90% compaction)
6 passes
a turning factor of .95% (loss of 5% efficiency)
go to the table in Walkers and solve the STANDARD problem.
6 passes in loam = 367 c.y. per hour.
367 * .5 (6" inch lifts) * 2 (10 ft roller) * .95 (maneuvering loss of 5%)= 348.65 c.y. per
hour
Answer: 10,000 cubic yards / 348.65 = 28.68 hours to complete the job.

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Dragline Yardages
This problem is a good deal like the sheepsfoot roller problems. You have a number of
variables, and you have a chart that has the standard answer. You get the standard
answer, and then modify the standard answer, or table answer to meet your site
conditions. A typical dragline has a 3/4 to 1 cubic yard size bucket.
1: The quantities in the tables represent cubic yards removed from the bank rather than
cubic yards in the hauling unit. There is a big difference between the two, this is because
of swell which will increase volume by 10% to 30% 2.16.
2: The optimum depth of cut for various sizes of shovel may be defined as that depth
which produces the greatest output and at which the dipper comes up with a full load.
3: The dragline is working a full 60 minutes each hour with no delays for adjustments,
lubrication., or operator needs.
4: The full dipper is swung through an arch of 90 degrees before dumping. This is
important, because a swing of either a lesser number or grater number of degrees than 90
degrees will either save or consume time and affect output capacity. The shorter the
swing the more yardage the shovel can dig.
5: The hauling units can hold a minimum of one dipper or shovel capacity and there are
enough trucks / train cars to take away all the material the shovel can dig 2.__.

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Problem:
What is the production capacity of a 1 cy bucket working in moist loam for one 8
hour shift.
Table 2__ Hourly Shovel Output in Cubic Yards.
205 cy per hour * 8 hours = 1,640 cy per 8 hour shift.
Table 2.__ Hourly Short Boom Dragline Output in Cubic Yards.
160 cy per hour * 8 hours = 1,280 cy per 8 hour shift.
2.__ The Table Giving Effect of Depth of Cut and Angle of Swing on Power Shovel
Output.
Note that the normal or optimal case occurs in the column where Depth of cut in % of
optimum l.f. = 100' and angle = 90°You can use this table to calculate other options,
such as 100' (100%) at 75° equals an increase of 1.07 (7%) over a 90° swing.
So if you were solving either of the above problems and they changed the swing to 45°,
60°, 75°, 120°, 150°, or 180° you will know to use this table amount as a percentage to
increase or decrease production.
45° = 126%
60° = 116%
75° = 107%
90° = 100%
120° = 88%
150° = 79%
180° = 71%

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Problem:
hour shift with a 75° angle of swing.
205 cy per hour * 8 hours = 1,640 cy per 8 hour shift* 1.05 = 1,722.00 *.97 = 1,670
160 cy per hour * 8 hours = 1,280 cy per 8 hour shift * 1.05 = 1,344.00 * .97 =1,304
There are other options the exam testers might use, such as 90° angle and an 80%
optimum capacity.
40' = 80%
60' = 91%
80' = 98%
100' = 100%
120' = 97%
140' = 91%
160' = 85%

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Problem:
hour shift with a 75° angle of swing and 40' optimum depth of cut.
205 cy per hour * 8 hours = 1,640 cy per 8 hour shift* 1.07 = 1,754.80 * .80 = 1,403.84
160 cy per hour * 8 hours = 1,280 cy per 8 hour shift * 1.07 = 1,396.60 * .80 = 1,117.28
The good news is that you will probably get a question right out of the book, like the first
example problem.

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Calculating diesel fuel
consumption rates
Let me begin by saying the answer to the questions on the exam will be .040 gallons per
hour per brake horsepower = consumption. Walkers Chapter 2.38 has a formula which
does provide a ball park for diesel fuel consumption, but the rule-of-thumb in 2 diesel
texts I checked is .040 (4%) gallons per hour per brake horsepower.
BPH * Factor * lbs fuel per horsepower hour
Weight of fuel per gallon
BPH = Brake horsepower, or rated horsepower for the engine
Factor = depends on load or torque of the engine; use 50% to 60%
Diesel = .5 lbs * brake horsepower
Diesel fuel = 7.3 pounds per gallon
To solve the problem of a diesel, skid sheet loader with a 75 hp diesel and an 18 gallon
fuel tank:
• (75 BPH * .50 * .5) / 7.3 = 2.57 gallons per hour. 18 gallons / 2.57 = 7 hrs.
• .040 * 75 BPH = 3 gallons per hour. 18 gallons / 3 = 6 hours.
Lubricating Oil:
Remember to add 15% to the fuel costs for lubricating oil.

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Hauling Calculations
Many factors affect the choice of what machine to use, the following are major
considerations in hauling calculations.
• Type of material to be excavated and hauled
• Site conditions
• Distance of haul
• Time allowed for job completion
• Contract Price
The following formula will help estimate the hourly production of a piece of equipment:
P = E * I * H
C
P = production, cu yd/hr (in-bank)
E = machine efficiency, min/hr
I = shrinkage factor for loose material
H = heaped capacity of machine, cu yd
C = cycle time of the machine, min
The production or volume of material that a piece of equipment can move is based on the
volume occupied by the material in its natural state or in-bank condition. Materials can
increase in volume by as much as 50%. To allow for this increase in volume, the
shrinkage factor I is applied to the heaped capacity H of the earthmover to reduce the
load to the in-bank condition.
In-bank machine capacity = H (heaped capacity) * I (shrinkage factor)
Formula for calculating shrinkage is; (This is worked out for you in PPCC).
I = 1
1 + % swell / 100

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Machine efficiency is included in the calculation as an average piece of machinery is
between 75% and 85% efficient. This efficiency percentage is assigned to the machine.
Some examples are:
• Crawler tractor 50 min/hr = 83%
• Rubber-tired hauling units 45 min/hr = 75%
• Large rubber-tired loaders and dozers 45 min/hr = 75%
• Small rubber-tired loaders 50 min/hr = 83%
Cycle time of a piece of equipment is based on the time required to obtain its load, move
it to its dumping point, and return to the loading point. Total cycle time is a combination
of cycle travel time + cycle fixed time.
C = CT + CF
Cycle time calculated in minutes;
CT = D
S * 88
D = distance traveled, in feet
S = speed, miles per hour
88 = distance moved per minute at 1 mph
All major suppliers have charts and data for the various pieces of equipment.
Example problem:
Calculate production for a crawler-mounted power shovel working in well-blasted rock
with a 1 1/2 yard bucket (heaped). The machine has an efficiency of 50 min/hr, and a
cycle time of 3 minutes. (According to PPCC pg 74 a heaped 11/2 yard bucket holds 2
yards).
1: The percentage increase in volume for rock is 50%
I = 1 / (1+ 50/100) = .67
2: P = E * I * H
C
(60*.83) * .67 * 2) / 3
67 cu yards / 3 = 22.33 CY

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So according to this calculation production should be about 22 yards an hour. Maximum
production for this shovel with a 3 minute cycle time is 60 /3 = 20 * 2 cu yd (heaped) =
40 cu yd hour.
Formwork
The actual area of the form that comes into contact with the concrete is used to calculate
formwork area. It is called square foot of contact area (SFCA). It may also be
calculated and priced by the linear foot.
There are two main types of footings; continuous strip footings, on which walls
will be erected, and isolated spread footings, which are used to support isolated interior
columns. Continuous strip footings follow the shape and perimeter of the wall, and are
wider than the walls they support. They are typically formed on both sides and braced on
the top and sides at 2' to 3' intervals. Metal straps are sometimes used to secure the
bottom of the footing; they are set at 2' to 4' intervals. The most common forms for
footings are 2" * 12" planking. Common sizes for footings are 20" to 36" wide by 12" to
18" deep. Footings are calculated by the LF, while stepped footings covering changing
elevations are priced separately. To minimize lateral movement of the wall a small
indentation, called a keyway is pressed into the top of the footing using a tapered 2" * 4"
shaped like a trapezoid. Spread footings are isolated masses of concrete, often square or
rectangular in shape, with thicknesses varying from 12" to 24". These spread footings
support point loads from columns that rest on them (PRMT, 101). Combined footings
are spread footings that carry loads at two or more column points. Spread footings are
priced by the piece (EA).
A wall, or a retaining wall is cast in place on top of a footing and is used to retain the soil
at or below grade. Formwork for a foundation wall is typically made of smooth plywood
sheathing applied with 2" * 4" bracing or steel frames called walers. Foundation walls are
made by doubling formwork on top of a strip footing. This creates a narrow box that is
typically 6" or 8" inches wide that holds the liquid concrete while it is cast-in-place. The
narrow box is held in place by ties that are typically placed 24" on center both
horizontally and vertically. Greater hydrostatic pressure may require more ties and more
walers. Walers are horizontal wood or metal braces that help contain the hydrostatic

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pressure on the wood sheathing DCCM, p.8). Average concrete has a dead load weight of
150 lb/cu ft, including the reinforcing. The live load is calculated to be 50 lb/cu ft. for
workers and equipment and if buggies are used a live load factor of 75 lb/cu ft. is used. If
you want to calculate the dead load pressure being exerted on a 6" slab: 150 lb/cu ft / 12
inches = 12.5 lb/ cu inch x 6 inches = 75 lb/cu ft of pressure.
A pier is short column of concrete, typically reinforced with re-bar that is used to support
structural load points. All types of formwork must be coated with a release agent to keep
the concrete from hardening to the wood and metal bracing. Grade beams are horizontal
beams set on concrete piers that in turn set on spread footings. In a beam or slab holding
a dead and or live load both vertical and horizontal shear are present and the net result of
the two forces is called diagonal tension. A crack resulting from these forces always
occurs near the support and extends upward and outward at an angle of approximately 45
degrees to the top. To resist the diagonal tension, small U or W shaped bars called
stirrups are used and are placed vertically across the beam. Since shear is usually at a
maximum near the support and decreases toward mid-span, the stirrups are more closely
spaced near the support and spaced increasingly farther apart toward mid-span. Steel is
usually used to resist tension forces, but in columns it is used to resist compression
forces. Since bars are about twenty times stronger than an equivalent area of concrete,
they are used to carry part of the column load (PRB, 5-7). The concrete and the steel
work together and the result is a column that is much smaller in size and lighter in
weight.
Pile foundations are used where the sub-grade is too soft to provide adequate bearing for
a normal footing. Piles are driven, a spread footing is poured and a column is placed on
the spread footing. After the piles for each footing are driven, they are cut off at the same
level. This is usually about six inches above the bottom of the footing. Elevated slabs or
cantilevered slabs are built like grade beams when they are cast-in-place. Edge forms
are the simplest of forms used for making sidewalks and pads. All the above are
measured in linear feet, and priced either by the linear foot or individually.
Expansion joints are typically filled with a joint filler which is an asphalt impregnated
fibrous boards 4" to 6" tall that is used to allow for safe expansion and contraction of the
concrete. Expansion joints are usually placed at the perimeter of the concrete slab where
it abuts a strip footing or spread footing. Control joints are a sawed groove in the
concrete surface that regulates cracking as a result of settling caused by dimensional
changes (settling) in large pours of concrete (PRMT, 107). Concrete reinforcement is
the placing of steel bars and wire lath within the formwork prior to the placing of
concrete. Welded wire fabric is used to control contraction in the concrete and to reduce
cracking due to settling. Reinforcing bars called re-bar is deformed or knurled round
bars of high-grade steel. Re-bar comes in standard sizes from 3, 4, 5, 6, 7, 8, 9, 10, 11, 12,
13, 14, 18. The number denotes approximately the diameter of the bar in eights of inches;
3/8, 4/8, 5/8, 6/8, 7/8, 8/8, 9/8, 10/8, 11/8, 12/8, 13/8, 14/8, 18/8. Sizes and weights per
foot of bars are given on a table on page 6.3 of Placing Reinforcing Bars.

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Re-bar Calculations
• You will be given the dimensions of the slab, or they will be on the plans.
• You will be told the spacing longitudinally (length), such as 16" OC.
• You will be told the spacing transverse (width), such as 12" OC.
• Divide the slab length by the spacing OC multiply by width.
• Divide the slab width by the spacing OC multiply by the length.
• Add both dimensions.
• Find the table with the weight per pound of #__re-bar.
• Multiply LF by weight per pound, on large jobs convert to tons.
Spirals (re-bar) are used in spirally reinforced columns, piers and piles and are made of
deformed bar; plain bar or wire bent to a specified diameter into a form similar to that of
a coiled spring. The spacing of the bar is important and spacers are sometimes provided
to hold this spacing, known as pitch. Table on 6.10 PRB provides the minimum number
of spaces required per diameter of spiral.
Spiral Wire Or Bar Size Spiral Core Diameter Minimum no of spacers
3/8" #3 > 20" 2
1/2" #4 20" - 30" 3
> 30" 4
5/8" #5 <= 24" 3
5/8" #5 > 24" 4

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Rebar is calculated in LF and converted to pounds or tons. One ton equals 2000 pounds.
Each size of re-bar should be listed separately for pricing. Don't call it re-bar on the
exam, that is the wrong answer, it is reinforcing bars.
Offset Column Bars are bent so that the upper part which projects above the upper floor
will come inside the vertical bars in the column above. All offset bends in a column are
made using the largest offset. Where the column faces are offset 3 inches or more, the
lower vertical bars stop below the floor and a separate short bar called a dowel is used,
extending below and above the floor line a specified distance (6.11 PRB). Re-bar is
usually shipped by flatbed truck. Sufficient lead time must be allowed the fabricator so
that detailing, approval of placing drawings, fabricating and delivery of bars. When a
bundle is opened and part of the bars removed, the bar with the tag should remain with
the bundle.
The main factors affecting bond are the presence of scale, rust, oil and mud. Scale
and rust do not pose a problem. Rust may in-fact improve the bond because it increases
the normal roughness of the surface. Mud coating the bars must be removed, oil or
grease must also be removed before placing the bars.
When hoisting bundles of bars thirty feet (30) or longer, it may be necessary to use a
spreader bar so that the bars will not bend excessively. If a spreader bar is not used, a
sling should be used so as to avoid picking up the bundle by the wire wrappings. The
sling must be made of wire rope not less than 1/2 inch in diameter. Slings are short
lengths of wire rope with a spliced eye at each end or a spliced eye at one end and a hook
on the other end (7.6 PRB).
The stress or tension on each choker depends on the number of chokers, the angle of the
choker, and the total load. The total weight lifted is divided among the supporting
chokers and acts straight downward. The greater the angle of the choker from a vertical,
the greater is the tension in the choker. This means that the strength of the hoisting line
determines the maximum lifting power of the combination. To determine the maximum
lifting power of the combination, it is necessary first to determine the tension on each
choker for a given load. This may be computed by the following formula: (PRB 7.9)
T= (W * L) / (N * V)
Given:
W, weight lifted (in pounds)
V, vertical distance from the load to the hook (in feet)
L, the length of the choker (in feet)
N, the number of chokers, is counted.
T, the result is the tension on the choker (in pounds)
Stock lengths of bottom bars in slabs are typically of 5 ft and 10 ft. Where more than one
length is used in a single line, they should be lapped so the end legs are locked or tied

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together which makes a 5" lap so the effective length of bolster will be 4'7" and 9' 7" in
respectively.
Overlapping of reinforcing bars is usually 16" to 18", however another way to
determine the minimum length of overlap is to say some factor times the diameter of the
rod, for example; 24 times the diameter for #5. To calculate the overlap length it is
necessary to turn a fraction into a decimal and multiply: #5 = 5/8 = .625 x 24 = 15". The
minimum length between the end of a slab cast against earth and the end of re-bar
placement should be a minimum of 3". It is important that bars be placed and held in
position as shown on the placing drawings. The strength of any concrete member can be
affected by the improper positioning of the reinforcing bars. For example, lowering the
top bars or raising the bottom bars by 1/2 inch more than specified in 6 inch deep slab
could reduce its load carrying capacity by 20 percent. Bars are normally stocked in 60 ft.
length. Field welding of crossing bars has shown that this can reduce the strength of a bar
to 35 to 40 percent of its original capacity. Wire used for tying reinforcing bars is usually
No 16 1/2 or No 16 gauge black, soft- annealed wire. It is not necessary to tie bars at
every intersection. Tying every intersection adds nothing to the strength of the finished
structure. In most cases, tying every 4th
or 5th
intersection is sufficient. On page 12-2 PRB
there is a 6 step process for placing bars in beams.
1: Beam bolsters are properly located and spaced at 5 ft O.C. maximum, resting on
the bottom beam form.
2: Stirrups are place with the closed end down, resting on the beam soffit and located
opposite chalk marks made along the forms from spacing taken form the beam schedule.
3: Bottom Bars are lowered into position inside the stirrups and rest upon the beam
bolsters, with the ends of the bars extending the proper distance into each support.
4: If bottom bars are to be placed in two layers, upper beam bolsters or bar separators are
laid in position and tied across the top of the bottom bars to support the upper layer of
bars.
5: Second layer bottom bars, is any, are lowered into place inside the stirrups upon the
upper beam bolsters.
6: top bars, continuous and/or short, are placed in the top and/or second layer. Bar
separators or upper beam bolsters can be used to support both layers of top bars as shown
on the beam section at the left.

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Design and Control
of Concrete Mixtures
For the exam you do not need to know much about the nature of concrete. Cement is the
name of the dry mix in the bag. Once all the components are mixed together and water is
added then the mix is called concrete. It is important that you know that concrete is a
plastic mixture of components. These components are Portland cement, aggregate,
sand, water, and additives to modify the nature of concrete.
Portland cement is a hydraulic cement. Portland cement is a compound made
primarily from hydraulic calcium silicate. It was patented by Joseph Aspdin in England in
1824, and is called Portland cement because it is similar in color to naturally occurring
stone found in Portland England. A bag of Portland cement weighs 94 lbs and has a
volume of about 1 cubic yard.
Hydraulic cement sets up underwater; therefore it must have sufficient water to
supply the entire hydration process. If the concrete is not kept damp it will not cure
properly and it will not reach the desired compressive strength, which will increase the
probability of cracking. Normal concrete reaches it desired compressive strength in 28
days. To determine compressive strength test cylinders 6” * 12” are made for testing
working samples of the concrete. Usually 4 to 6 samples are taken from each work area
during the course of the pour. Compressive strength tests also provide information on
flexural strength, tensile strength, tensional strength, and shear strength (page 5). Most
general use concrete should test out at between 3000 psi and 5000 psi. High early
concrete should have at least 6000 psi, and it is possible to order high early at
compressive strengths up to 20,000 psi (page 5).
Excessive amounts of water in the mix is not the answer to insuring proper
hydration, as this will dilute the Portland cement and weaken the compression strength of
the concrete. It is important to keep the concrete wet or damp for as long as possible,
ranging in periods from three days to one week, depending upon the desired compressive
strength.
In order to maintain a minimum 80% moisture content it is important to use a 6 mil
plastic liner under foundation pours. Another technique used in foundation pours is to

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saturate the sand with water, thus cooling the area, and allowing the concrete to absorb
moisture from the ground. It is also acceptable to use a lawn sprinkler or soaker hose, wet
burlap or a chemical coating over the top of the concrete to seal in the water after about 3
hours once the concrete has lost its workability. Concrete will continue to hydrate - gain
strength for up to 28 days so long as there is water available to continue the hydration
process. If the water is allowed to drain out of the concrete the hydration process will
stop before the concrete reaches it’s maximum strength. What is equally important is that
there will be un-hydrated cement powder in the concrete mix that will have a tendency to
cause pop-outs, cracking, and structural weakness.
Portland cement acts as an adhesive to hold the aggregate together to form a rock like
substance. Cement powder usually constitutes about 25% to 40% of the total volume of
concrete. Aggregates are sand and stone used in the making of concrete and constitutes
60% to 75% of concrete volume. Fine aggregates range in size from sand beads to 3/8”
thick crushed rock. Coarse aggregates are larger than 3/8” and can be up to 11/2” thick.
The largest size of aggregate you should use is 1/3 the depth of slabs, 1/5 the smallest
dimension of a vertical pour, or ¾ the clear spacing between reinforcing bars (page 36).
The purpose in using large and small aggregates together is to minimize voids in the
concrete. The more aggregate used in the concrete the less expensive the concrete mix
will be. More water and cement is required for small-size aggregates than for large size
aggregate. The amount of cement powder required decreases as the maximum size of
coarse aggregate increases. Concrete with the smaller maximum-size aggregate has
higher compressive strength. This is especially true of high-strength concrete (page 35).
The specific gravity of concrete is important when you are building forming to
contain the liquid concrete, and when you are making a concrete pour on a flat roof. The
specific gravity of most aggregates ranges from a normal specific gravity of 2.4 which
equates to 150 pcf including the weight of reinforcing bars, to an upward range specific
gravity of 2.9 which equates to 181 pcf including the weight of reinforcing bars. (WEG
3.11;DCCM p8) Light weight concrete for roofs made from pearlite or vermiculite
aggregates typically has a specific gravity of 100 pcf. Specific gravity of aggregates is
based on a relationship between the weight of a given volume of stone and an equal
volume of water. Water weights 62.4 pounds per cubic foot, so a cubic foot of aggregate
should weigh 62.4 * 2.4 = 149.76 pounds up to 62.4 * 2.9 = 181 pounds per cubic foot.
The quality of water used in concrete has an important impact on the final product. Clean
tap water is preferred when available. Silt or clay in the water will have the effect of
forming a fine layer between the aggregate, the reinforcing bar and the hydraulic cement.
Silt and clay can weaken the bond of concrete resulting in cracking and premature aging
of the concrete. Alkali sodium carbonate can cause the concrete to set very rapidly.
Chlorine in the water can cause the reinforcing bars to corrode. Sodium or seawater can
only be used in un-reinforced concrete pours. When salt is present the water-cement ratio
must be reduced to maintain normal strength of the concrete. Excessive amounts o f oil in

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the water can decrease concrete strength by up to 20%. For this reason it is important
that excessive amounts of release agent not be sprayed on forming boards.
Air-Entrained concrete is used to increase the working life of concrete that is
subject of freezing and thawing. Air-entraining is accomplished by adding an agent that
traps air bubbles in the concrete similar in nature to a soap film (page 47). The air
bubbles are extremely small between 10 µm to 1 millimeter and are intended to be
distributed throughout the concrete pour. Air-entraining improves the workability of
concrete, and a steel-troweled surface will resist abrasion more than a surface that is not
troweled (page 9). At the same time, beware of premature finishing air-entrained
concrete, as this will reduce the amount of air bubbles at the surface level which will
allow scaling and frost damage on the surface (page 58). To minimize cracking in
concrete the most effective method is to use control joints, and properly positioned
reinforcing steel bars (page, 10). Control joints should not be confused with construction
joints which are used to contain separate pours, such as the last pour of the day from the
first pour the next morning.
There are 5 common types of Portland cement. Each type of cement has preferred
applications. Type 1 Portland cement is general-purpose cement suitable for all uses,
such as pavements, floors, building walls, ridges, tanks, reservoirs, pipes, masonry units,
and precast concrete products, but Type 1 lacks special properties. Type 1 is the standard
for heat transmission during the hydration process, all other types heat transmission is
referenced to Type 1. Heat generation is important when pouring vertical walls and
columns. The contractor either has to pour hot concrete at a slower rate or switch to a
cooler mix to minimize pouring time. Type 1-A is Type 1 concrete with air-entraining
agents added for frost protection. Type 2 Portland cement is used where salt (sulfates) are
likely to attack the concrete. Type 2 Portland cement generates less heat over a longer
period that Type 1 Portland cement. The amount of heat generated during the hydration
process can usually be specified when ordering Type 2 concrete. Type 3 Portland cement
is generally called high-early, reaching high strengths usually within a week or less.
Type 4 Portland cement generates minimal heat during the hydration process. Type 4
gains strength slower than other types of concrete, and is used in very thick pours. Type 5
Portland cement is only used for concrete exposed to high levels of sulfates. Sulfate
resistance can also be increased by air-entrainment or enriching the cement mix.
White Portland cement is commonly made from Type 1 and Type 3 Portland cement.
White Portland cement is primarily a cosmetic product and conforms to the same
specifications as gray Portland cement. Waterproofed Portland cement is made by
adding stearate to the Portland cement during final grinding (page 19).
In proportioning concrete the objective is to design a concrete that is workable, durable,
strong, uniform in appearance and economical (page-77). There are two methods for
determining proportioning volumetric method and the absolute-volume method. A
common volumetric mix is 1-2-3, 1 part cement, 2 parts sand, and 3 parts coarse

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aggregate. The absolute-volume method uses the specific gravity of the components to
determine the mix ratio. The number one factor in the quality of cement is the quality of
the cement paste.
The quality of the cement paste is determined by the water-cement ratio. The less
water that can be used, in proportion to cement, generally the stronger the concrete will
be. The water-cement ratio is simply the weight of water divided by the weight of cement
(page 78). On the other hand, the concrete can not be starved for water, as the cement
continues to gain strength so long as there 80% relative humidity available and an
acceptable temperature above 40° degrees Fahrenheit. It is possible to create a stronger
mix by modifying the nature of some of the components of the concrete mix. The larger
the size of aggregates used the less water required which will result in a richer mix, or the
cement paste can be cut back to lower construction costs. Rounded aggregates require
less water than crushed sharp aggregates, again promoting a richer mix or a more
economical mix. If you are trying to increase the compressive strength of the concrete,
then limit the aggregates to ¾” and use crushed stone rather than rounded stone. In
making air-entrained cement the use of larger size aggregate will reduce the amount of
air-entrained additive required as the aggregate will take up more space in the concrete.
Slump refers to the consistency, workability and plasticity of concrete. Workability
is a measure of how difficult it is to place and finish concrete. Consistency and plasticity
reflect the ability of fresh concrete to flow into the forming. Slump is a measure of
consistency and workability, generally the higher the slump the wetter the concrete (page
80). Slump is generally specified in a range from 2” to 4” inches. When you need to
adjust slump, a rule of thumb is that 1” in. of slump can be created by adding 10 lbs of
water per cubic yard of concrete. Slump may be increased by 1” for hand placement and
consideration (page 80).
Slump Recommendations maximum minimum
Foundations and footings 3 1
Caissons and substructure walls 3 1
Beams and reinforced walls 4 1
Columns 4 1
Pavement and slabs 3 1
Bulk concrete 2 1
Page 81
To decrease the water required in concrete use larger aggregate, reduce the water-cement
ratio, reduce the slump, use rounded aggregates, use water reducing admixtures, and fly
ash. To increase water required, pour concrete in hot temperatures, increase water cement
ratio, increase slump, use fine angular aggregate. When trying to achieve a specific mix

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you can make trial mixtures varying the water-cement ratio in 3 6” x 12” test cylinders
to define a specific compressive strength.
In reality you call up CSR-Rinker and they have cylinder test results available
for a wide variety of mixes. This established data available from CSR-Rinker can be
relied upon for bidding contracts.
Batching is the accurate process of weighing or controlling the volume of measuring
ingredients as the are put in the mixer. Specifications generally provide the following
margin of error 1% for cement, 2% for aggregates, 25 for water, and 35 for admixtures
(page 94). Concrete batches are required to be delivered and poured within 11/2 hours or
before 300 turns of the mixer drum after introducing all elements (Portland cement,
aggregates, water) of the concrete mix. In placing concrete the rate of placement should
be between 6” and 20” per pour for reinforced members, and 15” to 20” for thick mass
work” (page 104). Concrete should be set at a rate that the previous layer has not set
before the new layer is placed in the forms to avoid flow lines, seams, and cold joints
(page 104).
If you are going for the General Contractors exam then it is important to read the entire
book Design and Control of Concrete Mixtures, as it is an important part of the second
day of the exam. The following is a summary of concrete information from Walkers.
Materials and Types of Concrete:
Concrete is a composite material composed of sand, coarse aggregate, cement and water,
which is applied in a plastic or liquid state. Under normal temperatures, the initial set
will occur in hours. The greatest asset of concrete is its high compressive strength,
durability, and ability to withstand weathering (PRMT p 97).
When concrete is combined with steel reinforcing bars the concrete takes on the ability to
withstand elongation, which is called high tensile strength. Protecting concrete with a
covering in the early period to prevent loss of moisture in hot dry air, or at low
temperatures is an important factor in the development of both strength and durability in
concrete. A plastic liner can be used under the concrete and wetted burlap covering the
top, or a chemical spray to prevent moisture loss.
When calculating concrete requirements the contractor needs to look at all the drawings
in the set including those prefaced with S, A, M, E, for applications of concrete.
Takeoff considerations that effect pricing:
• A specified compressive strength per square inch (psi), have different cost
structures; for example: 3000 psi, 3500 psi, 4000 psi.
• Additives that accelerate drying time, such as high early strength Portland cement
that will achieve the same strength in 72 hours that other types of concrete
normally achieve in 7 to 10 days. Concrete usually achieves its full rated strength
in 28 days (PRB, 2.1).

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• The size and type of aggregate used will affect cost.
• Air entrainment, which increases workability and weathering characteristics,
uses additives of 3% to 6% of volume.
• Chemicals such as calcium chloride, for fast drying, increase costs.
• Using perlite or vermiculite as the aggregate for making light weight concrete, as
used over corrugated roofing, adds considerably to costs.
Ready-mixed concrete, which is produced off site, has become the industry standard due
to better quality control of the mix. The typical minimum delivery quantity is 5 CY,
commonly referred to as short loads. Consistency is loosely defined as the wetness of
the concrete mixture. It is measured in terms of slump – the higher the slump the wetter
the mixture and it affects the ease with which the concrete will flow during placement. It
is related to, but not synonymous with, workability (3.130). The specification also
requires that the concrete must be delivered and discharged from the truck mixer or
agitator truck within 1-1/2 hours after introduction of the water to the cement and
aggregate or the cement to the aggregate (Walker 3.145). When factoring waste calculate
3% unless there is a lot of transporting, or moving with wheel borrows, in which case
calculate a 5% waste. Test cylinders, which are steel molds 6" in diameter by 12" high
are used to obtain samples of concrete. After either 7 days or 28 days of curing, the
samples are crushed to insure the concrete meets minimum compression strength (PRB,
5-1). Concrete is measured by the cubic foot and converted to cubic yards by dividing
cubic feet by 27. CF / 27 = CY

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Trusses
Structural performance depends on the trusses being installed vertically, in-plane, and at
specific spacing, and being properly fabricated and braced. (p.2). There are many critical
phases regarding safety including; loading, shipping, receiving, unloading, shoring,
installation and bracing of trusses. By far the majority of wood truss related accidents
occur during truss installation, not as a factor of design fault.
Major causes of wood truss collapse are as follows;
• inadequate or improper bracing
• improperly installed or inadequate bracing connections
• improper and or inadequate connections to supporting structure
• overloading of roof and floor trusses before permanent bracing has been installed
• Most common overloads are stacks of plywood placed on trusses before the
trusses are properly braced.
• Improper field alterations of trusses
• Installation of broken, damaged, and improperly repaired trusses
• Improper truss alignment
• Improperly engineered or installed wall structures
• Failure to provide proper bracing during installation

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The builder, licensed contractor, who pulled the permit is responsible for the
proper receiving, unloading, storage, handling, installation and bracing of metal plate
connected wood trusses and will henceforth be referred to as the installer!
Hauling:
A truss should be supported at intervals of 25 feet or less. A truss is a manufactured
assembly, not a monolithic product. The trusses must be maintained in alignment before,
during and after installation. Banding should be placed as close to panel points as
possible to prevent bending of the lumber. Banded truss bundles transported in a
horizontal position should be stacked on the trailer so as to prevent excessive bending.
Receiving:
It is the contractor's responsibility to inspect trusses for damage at the destination
point (job site). Verification of delivery ticket or bill of lading listings should be checked
against an actual piece count. The receiving party should look for any permanent
damage such as cross breaks in the lumber, missing or damaged metal connector plates,
excessive split in lumber, or nay damage that impairs the structural integrity of the truss.
Any deficiency should be noted on the receiving documents. Unless notation is made on
these documents, the truss manufacturer will generally assume no responsibility for
damage to the truss. A piece count as also helpful in avoiding delays in the vent any items
are missing. In the case of damage, notation of any deficiencies should be made on the
delivery documents.
Unloading:
Care should be taken at every phase of handling of trusses to avoid lateral bending of the
trusses. A crane with a spreader bar and cables is strongly recommended for trusses with
spans grater than 30 feet. The strapping is not strong enough to safely support the weight
of trusses, so never lift bundles by their strapping. Do not attach cables, chains, or hooks
to the web members. Lift underneath the top chords about 1/4 to 1/3 of the way from the
peak. Whenever possible, trusses should be unloaded in bundles. Trusses should be
loaded on smooth ground causing no distortion or strain. All banded trusses should be
picked up by the top chords in a vertical position only. The smooth dry ground the trusses
are placed on should be as close to the building site as possible to minimize handling.
Trusses manufactured with fire retardant lumber should not be subjected to impact load,
such as dropping, which may impart the structural integrity of the truss. All trusses,
which are installed one at a time, should be held safely in position with the installation
equipment until such time as all necessary bracing has been installed. Hand installation of
trusses is allowable provided lateral bending is prevented.

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Storage:
If trusses are stored horizontally, the blocking should be on eight to then foot centers to
prevent lateral bending. If the truss bundle is to be stored for more than one week, the
solid blocking, generally provided by the receiving party, should be at a sufficient height
to lessen moisture gain from the ground. Do not break banding until installation begins.
Pitched trusses should not be stored with the peak down and scissors trusses should not
be stored with the peak up. Bundles should be placed in a horizontal position before
banding is removed. If tarpaulins or other water resistant materials are used the ends
should be left open for ventilation. Trusses made with fire retardant lumber should have
minimal exposure to the outside. Trusses stored vertically should be braced in a manner
to prevent topping or tipping. Without bracing trusses are laterally unstable. Trusses may
be installed either by hand or by mechanical means. The contractor should be
knowledgeable about the truss design drawings, truss placement plans, and specification
notes.
Hand Installation:
Excessive lateral deflection is that which produces strain in the lumber or metal
connector plates, which will weaken the joints.
Any lateral deflection greater than three 3" inches in a ten foot span should be
considered excessive. Trusses should be handled so as to ensure support at intervals of 25
feet or less. Depending on length, the truss should be supported at the peak for spans less
than or equal to 20 feet, and at quarter points for spans less than or equal to 30 feet.
Sufficient control should be used during lifting and placement to assure safety to
personnel and to prevent damage to trusses and property. Slings, tag lines, spreader bars
should be used in a manner that will not damage the metal connector plates on the
trusses. Lifting devices should be connected to the truss top chord with a closed-loop
attachment utilizing materials such as slings, chains, cables, nylon strapping, etc. of
sufficient strength to carry the weight of the truss. For truss spans less than 30 feet a
suggested procedure for lifting is illustrated in figure 11. For truss spans 30 feet to 60
feet, a suggested lifting procedure is shown in figure 12. Lines from the ends of the
spreader bar should "toe-in" Do not permit the lines to "toe-out" since this will tend to
cause bucking of the truss. The angle of the bridle or harness used to lift the trusses
should ideally form a 60° angle. Tag lines should be tied at the end of the truss to
facilitate guiding the truss into place. A spreader bar should be 1/2 to 2/3 the length of
the trusses 60' or less.
On trusses longer than 60' a strong back spreader bar should be used. A strong
back spreader bar differs from a spreader bar in that the strong back is actually attached
to the truss. It is important that the truss be properly braced before the hoisting equipment
and lines are released.

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Building Lines and Dimensions:
The builder or contractor of record is responsible for the accurate location of building
lines and elevations. Jobsite dimensions and coordination of truss drawing dimensions
(and truss placement plan, if submitted) are the responsibility of the builder of record.
The builder of record should verify truss drawing dimensions, and truss placement plan,
if submitted, and return approved copies to the truss manufacturer in sufficient time for
fabrication and delivery in accordance with the agreed construction schedule. The builder
of record must pay attention to lines and dimensions to assure that:
• The load bearing surfaces (top plates) are level where required to be level;
• The overall dimensions (length, width, height, diagonal) are correct, and all
bearing walls are plumb and properly braced;
• The load bearing surfaces (top plates) are straight in their lengths, and parallel
where they should be parallel;
• Special supporting structures are installed accurately at the locations shown on the
plans;
• Supporting structures are capable of safely carrying the wood truss system during
the after their installation.
Anchors and Ties:
All tie-downs, seats, bearing ledgers, and anchors should be properly attached. Trusses
should not be installed on anchors or tie-downs which have temporary connections to the
supporting structure. Trusses should not be installed over loose lintels, shelf angles,
headers, beams, or other supporting pieces.
Installation Tolerances:
Installation tolerances are critical in achieving an acceptable roof or floor line and in
establishing effective bracing. Use of a stringline, plumb bob, level or transit is
recommended in order to achieve acceptable installation tolerances.
Trusses should not be installed with a variation from plumb (vertical tolerance) at
any point along the length of the truss from top to bottom chords with exceeds 1/50 of the
depth of the truss at that point (D/50) or two inches, whichever is less. Location of trusses
along the bearing support should be within +- 1/4 inch of plan dimensions. Trusses are to
be located at the on-center spacing specified by the truss design engineer. Top chord
bearing parallel chord trusses should have as a maximum gap 1/2" between the inside of
the bearing and the first diagonal or vertical web as shown figure 16 on page 27.

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Ground Bracing:
Ground bracing should be of no less than 2x4 grade marked lumber or other structural
bracing materials at the discretion of the designer.
Splices:
Splices for ground bracing should occur only at a point that is laterally braced. Splices for
ground bracing, if constructed with wood members, should have a minimum three foot
overlap nailed with a minimum of ten 16d x 3 1/4 inch nails, nailed in accordance with
NDS.
Responsibility:
The builder / contractor is responsible for the proper selection of lumber sizes,
connections and installation of the ground bracing system.
Lateral Bracing:
All temporary bracing should be no less than 2 x4 grade marked lumber, should be 10
feet long, and should have design values in accordance with the NDS (National Design
Specifications)! End diagonal brace transfers brace force to the support structure and
must be attached to a fixed point of the structure. All connections should be made with a
number of nails as specified by the designer. All lateral braces lapped at least two
trusses.
Continuity:
Bottom chord lateral bracing (LB) may be applied to the top or underside of the chord
member and should be at least 2 x 4 grade marked lumber, nailed with a minimum two
16d nails.
Permanent Diagonal Braces:
Generally for pitched roof trusses, the spacing ranges from 12 to 16 feet, depending upon
how it relates to bracing in the plane of the top chord. All bracing lumber should be no
less than 2 x 4 – 10 feet long. A minimum of two 16d double head nails should be used at
each connection.
Read all the Truss Tips:
Trusses, which do not meet interior load bearing walls, should be shimmed for adequate
bearing.

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Board Feet Calculations
Board Foot formula:
BF = (t*w*l / 12) * number of planks
(t = thickness; w = width; l = length)
1 piling 2" * 8" * 10' / 12 = 13.33 board feet per plank
314' (diameter of excavation)* 12" = 3,768" (inches diameter of excavation)
3,768" / 7.25" (actual width of 8" board) = 519.72 or 520 boards T&G
520 * 13.33 board feet = 6,931.60 total board feet of lumber required.
Or
You can say 7.25" actual width of board / 12" = .604: 314' excavation / .604 = 519.86 or
520 boards T&G * 13.33 board feet per plank = 6,929.83 total board feet required
WEG 2.111.6 Chart Answer

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Gypsum Manual
1.2 Where fire resistance or sound control is required for gypsum board systems, the
applicable building code regulations shall be followed. System details for fire and sound
rated systems are described in the Gypsum Association's Fire Resistance Design
Manual GA-600.
1.6 Attics or similar unheated spaces above gypsum board ceilings shall be ventilated by
providing cross ventilation for all spaces between the roof and the top floor ceiling.
1.6.1.1 A vapor retarder having a water vapor transmission rate not more than 1 perm (57
ng / pasm) shall be installed on the warm side of ceiling framing (6 mil vapor barrier).
1.6.2 Attic space that is accessible and suitable for future habitable rooms or walled-off
storage space shall have not less than 50 percent of the required ventilation area located
in the upper part of the ventilation space as near the high point of the roof as practical and
above the probable level of any future ceilings.
Section 2 has a description of terms and specification of materials. Read thought the
whole section.
2.1.1 Control joint – a designed separation to allow for expansion and contraction.
2.1.2 Edge – paper bound edge
2.1.3 End (butt) mill cut or field cut end perpendicular to the edge, core is exposed.
2.1.4 Fastener is a, nail, screw, staple used to attach board.
2.1.5 Finishing – taping of joints, concealment of taped joints, fastener heads and edge
corner bead.
2.1.6 Framing member – framing, furring, bridging, and blocking to attach gypsum on.
2.1.7 Gypsum Board "the generic name for a family of sheet products consisting of a
noncombustible core primarily of gypsum, with paper surfacing."
2.1.8 Parallel Application - gypsum board applied with edges oriented parallel to
framing members.
2.1.9 Perpendicular Application – gypsum board applied with edges oriented at
right angles to framing members.
2.1.10 Skim Coat – a thin coat of joint compound or material manufactured specifically
for this purpose, applied over an entire wall and / or ceiling surface to reduce surface
texture and porosity (suction) variations.
2.1.11 Treated Joint – a joint between gypsum boards which is reinforced and concealed
with tape and joint compound, or covered with strip moldings.
2.1.13 Untreated Joint – a joint between gypsum boards, which is left exposed.

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Materials:
2.2.1.4 Exterior Gypsum Soffit Board
2.2.1.5 Type X is special fire resistant gypsum wallboard.
2.2.1.6 Foil Backed Gypsum Board – regular gypsum or X type gypsum with a foil vapor
retarder laminated to the back surface.
2.2.2 Fiber Reinforced Gypsum Panels. Type X with Fiber Reinforced gypsum panes.
2.2.3 Joint Compound – mud must comply with ASTM 475
2.2.4 Water – H2O
2.2.5 Nails,
2.2.6 Screws
2.2.6.1 Type G screws, for attaching gypsum to gypsum. Type S screws, for attaching
gypsum board to light gage steel framing and wood framing. Type W screws, for
attaching gypsum board to wood framing members shall comply with ASTM C 1002.
2.2.6.2 Type S-12 screws for attaching gypsum to heavy gage steel framing members.
2.2.7 Staples shall be 16 gage, flattened, galvanized, divergent point wire staples
with not less than 7/16 in. wide crown outside measure.
2.2.8 Adhesives for attaching gypsum to wood and steel framing
2.2.9 Framing Members
2.2.9.1 wood
2.2.9.2 steel
2.2.9.4 Gypsum studs shall be not less than 6" wide and 1 inch thick and of lengths
approximately 6" less than the floor-to-ceiling height unless full-height lengths are
required for fire stops or for fire resistance. They shall be of either 1" gypsum
board or multi-layer gypsum board laminated to the required thickness.
3 Delivery, Identification, Handling, and Storage.
3.2 Materials shall be kept dry, above ground, fully protected from weather
3.3 Gypsum board shall always be stacked flat – Never on edge or end. Gypsum
stacked on edge or end is unstable and presents a serious hazard in the work place.
4 Application of Gypsum Board
4.1.2 Wood framing, members to which gypsum board is to be attached shall be
straight and true. The attachment surface of any framing member shall not vary
more than 1/8 inch from the plane of the faces of adjacent framing members.
4.1.3 When gypsum is attached to a ceiling, furring members shall not be less than 1 1/2
x 1 1/2 actual size (nominal)
Notice Table 1,2, and 3 for farming and spacing, fastener lengths.
4.3.1 Where materials are being mixed or used for joint treatment or for laminating
gypsum board the room temperature shall be maintained at not less than 50° F. for a

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