04 masonry

1. MORTARS AND PLASTERS

- a proportioned mixture of siliceous materials (sand, crushed stone)
and cement (lime, Portland) which, after being prepared in a plastic
state with water, hardens into a stonelike mass.
• Mortar is cement mix used to glue masonry units to each other, or
other surface finishing materials like tiles, bricks, stones to a
receiving structure like a wall or floor.
• Plaster is mortar applied to wall surfaces as a preparation or a hard
finish coat.


1.01 CEMENT MORTAR

- is a proportioned mixture of cement, fine aggregate and water.

- For first-class mortars 1 part of cement should be added to not more
than 3 parts of sand.

- Replacing 10 or 15 percent of the cement by volume with hydrated
lime gives greater workability and increases the strength of the mortar.

- For rubble stonework, 1 : 4 will be much stronger than lime mortar.

- For the top surface of floors and walks, use 1 : 1 to 1-1/2.

- Mortar made with fine sand requires a much larger quantity of cement
to obtain a given strength than mortar made with coarse sand.


1.01 CEMENT MORTAR

- Mortar may be mixed by hand or mechanical mixers, the latter
being preferred for large quantities.
- When the mixing is done by hand, it should be done on
platforms made watertight to prevent the loss of cement.
- The cement and sand should be mixed dry in small batches in
the proportions required on a clean platform.
- Water is added and the whole remixed until it is homogeneous
in color and leaves the mixing hoe clean when drawn out.
- Mortar should never be retempered after it has begun to set


1.02 PLASTER

- is a mortar of cementitious material ( lime, gypsum or cement),
sand and water which is applied in coats (layers) to masonry
surfaces, lath or various types of plaster board to give a hard finish
surface to interior or exterior walls and ceilings.
- the word “plaster” refers to gypsum plaster and the words gypsum
and plaster are often used interchangeably.
- Fiber or hair is sometimes added to the mixture to give increased
strength as when used for the first coat.
- Plastering is done according to two basic methods: two-coat and
three-coat. A three-coat job consists of :
• a first binding coat called scratch coat;
• a second straightening coat called the brown-coat; and
• a final coat called the finish coat.
In the two-coat work, the scratch and brown coats are combined into one.


1.03 TYPES OF PLASTER AND THEIR USES
a. Lime Plaster

Lime putty (hydrated lime and water), mixed on the job with sand
and gypsum plaster, used for two and three-coat finish surfaces
for interior walls and ceilings.
Scratch coat : 1 part lime putty, 1 part Portland cement or
Keene’s cement, 2-3/4 parts sand by weight.
Brown coat : 1 part lime putty, 1part Portland cement or
Keene’s cement, 3 parts sand by weight.
Finish coat:
Hard finish : 1 part lime putty, 1/3 gypsum plaster by volume
Sand float : 1 part lime putty, ¼ gypsum plaster, 2 parts sand
by volume


b. Gypsum Plaster

• Gypsum plaster. Plaster of Paris mixed with clay, lime and
other materials in combinations covered by trademarks or
patents. Mixed on the job with water, sand, lime putty, hair or
fiber for two or three-coat finish surfaces for interior walls and
ceilings; or used dry as ingredient for hard or sand float finish
with lime plaster (see above).

• High-strength gypsum plaster. Same as gypsum plaster but
mixed to meet established standards. Mixed on the job with
water, sand, lime putty, hair or fiber for two and three-coat finish
surfaces for both exteriors and interiors.
- Scratch and brown coats : 1 part high-strength gypsum
plaster to 2 parts sand by weight.
- Hard finish : ¼ lime putty to 1 part high-
strength gypsum plaster by volume


b. Gypsum Plaster

• Fibered gypsum plaster. Gypsum plaster premixed with
fibers. Mixed on the job with water and sand for scratch coat for
three-coat plastering job

• Prepared gypsum plaster. Gypsum plaster mixed with fine
white sand. Used for two and three-coat finish surfaces for
interior walls and ceilings .
- Scratch and brown coats : mix per manufacturer’s instructions.
- Finish coat: Any type of final coat plaster
(gypsum, Keene’s cement, lime or
prepared finish coat


b. Gypsum Plaster

• Bonding plaster. Gypsum plaster mixed with ingredients
develop more adhesive strength in combinations covered by
trademarks or patents. Used for interior finish for smooth
concrete walls or ceilings. Mix and apply as per manufacturer’s
directions

• Lightweight gypsum plaster, fire-resistant plaster. Gypsum
plaster mixed on the job with water, perlite, vermiculite or other
suitable mineral aggregate. Lightweight gypsum plaster is used
when weight is important, and for fire-proofing other materials
such as steel. Applied on lath. For interior use only .
- Scratch and brown coats : 2 sand, 2 cu. ft. perlite or vermiculite per 100 lb.
of plaster.
- Brown coat: 3 sand, 3 cu ft. perlite or vermiculite per 100 lb.
of plaster.
- Finish coat:
Hard finish: 1/3 gypsum plaster, 1 lime putty by volume
Sand Float Finish: 1 gypsum plaster, 1-1/2 sand by volume


b. Gypsum Plaster

• Keene’s cement. Plaster of Paris mixed with alum or borax or
other materials and burned (calcined) at 932 F. Mixed on the
job with water, lime putty and fine white sand as hard finish for
two and three-coat gypsum plaster. For interior use only
- Hard finish : 1 Keene’s cement, ¼ lime putty,
1/10 fine white sand by weight .
- Sand float finish : ½ Keene’s cement, 2 lime putty, 4 ½
sand by volume.
• Plaster of Paris. For ornamental plaster work and castings.

• Molding plaster. For ornamental plaster work and castings. Mix
with water as per manufacturer’s directions.

• Acoustics plaster. For acoustic treatment of interior walls and
ceilings. Applied on gypsum plaster base coats. Mix with water as
per manufacturer’s directions.


c. Portland Cement Plaster

• Mixed with water, sand and lime putty. Used for two and three-
coat finish surfaces for exterior and interior walls and ceilings
- Scratch and brown coats : 1 cement, ¼ lime putty, 3 sand.
- Sand float finish : 1 cement, ¼ lime putty, 3 sand.
• Thickness of plaster coats depends on the type of material to
which the plaster is applied. Generally, the total thickness is
5/8” on metal lath and ½” on lathing board and gypsum block.

• In three-coat plastering work, the scratch and brown coats are
¼” thick at minimum; the finish coat is 1/8” with a minimum of
1/16” at any point.

• For two-coat work, the base coat is ½” and the finish coat is the
same as three-coat work.


d. “Sgraffito”
• is highly decorative type of plaster work developed in Italy during
the Renaissance. This type of technique consists of applying two or
three thin coats of plaster different colors and then cutting away
certain areas of one or two coats to produce a three-dimensional
colored design.

2. UNIT MASONRY

2.01 DEFINITION
Masonry - is a built-up construction or combination of building
materials as clay, concrete, or stone set in mortar; or
plain concrete.

Masonry Terms:
a. Bed – The horizontal surfaces on which the
stones or bricks of walls lie in the courses.

b. Course – A continuous layer of bricks, stones,
Course
or other masonry units

c. Wythe or Tier – Each continuous, vertical
section of the wall, one masonry unit thick.
Wythe
or Tier

2. UNIT MASONRY

2.01 DEFINITION

Masonry Terms:

d. Bond – That connection between bricks, stones
or other masonry units formed by lapping them
one upon another carrying up the work, so as to
form an inseparable mass of building, by
preventing the vertical joints falling over each English Bond
other (also called a breaking joint).

e. Stretcher – A brick or block masonry laid
lengthwise of a wall Stretcher

f. Header – A brick or block masonry extending
over the thickness of the wall
Header

2. UNIT MASONRY

2.01 DEFINITION

Masonry Terms:

g. Heading course – A course in which the bricks
or other masonry units are all headers.

h. Soldier – A unit laid on its end with its face
perpendicular to the face of the wall.
Soldier

i. Quoins – The corner stones at the angles of
buildings, usually rusticated so as to project
from the normal surface of the wall.

j. Bond Stones – Stones running through the
thickness of the wall at right angles to its face,
in order to bind it together.

k. Blocking or Blocking Course – A course of
stones placed on top of cornice crowning the
walls

2. UNIT MASONRY

2.02 STONE

- Stone, together with wood and clay, are the basic building material
of man. The history of architecture until as late as 1900 was largely
the history of stone in architecture,

- Stone was the structural material, the
exterior and interior finishing material,
the flooring material and in many cases
the roofing material.

- It was also used for all types of
sculpture, statuary, and decorative and
ornamental applications.

- Today, stone is largely used as a
surface finishing material for both the
exterior and interior of buildings.

2. UNIT MASONRY

2.02 STONE

- Stone commonly used for architectural purposes include

granite limestone

marble sandstone

travertine slate.

2. UNIT MASONRY

2.02 STONE

They are commonly classified as:

a. Rubble Stone. Stone
delivered from the quarries
rough and irregular shape.

b. Dimension Stone. Stone
cut into specific size,
squared to dimensions, and
to a specific thickness

2. UNIT MASONRY

2.02 STONE

- STONEWORK: The types of stonework are based on the shape
and the surface treatment of finish of the stone :

a. Rubble work. Masonry of
rough, undressed stones.

When only the roughest
irregularities are knocked off, it
is called scabbled rubble, and

when the stones in each course RUBBLE WORK

are rudely dressed to a nearly
uniform height, range rubble .

b. Random work. Stones fitted
together at random without any
attempt to lay them in course.
RANDOM WORK

2. UNIT MASONRY

2.02 STONE

- STONEWORK:
c. Ashlar. Squared stones in regular courses, in contradistinction to
rubble work .

• Ranged work or coursed
ashlar – Uniform courses with
stones uniform in size.

RANGED WORK

• Broken range ashlar – Course
laid with the horizontal joints
uninterrupted but the width of the
courses and the length of the
stones are varied to produce a BROKEN
wall with a less regular pattern. RANGED WORK

2. UNIT MASONRY

2.02 STONE

- STONEWORK:
c. Ashlar

• Random course their rectangular
shape and are laid on horizontal
beds but no effort is made to RANDOM
COURSE WORK
continue the horizontal beds
through in an uninterrupted
manner. Large stones combine with
small ones in a convenient and, if
possible, an interesting manner.
• Rustic or Rock work - RUSTIC OR
Courses of stone face which ROCK WORK

is jagged, so as to present a
rough surface. * Rustication occurs when heavier
stones or areas of stone project
from the normal face of the
surrounding wall or of the joint
themselves.

2. UNIT MASONRY

2.03 BRICKS

- are structural units of clay or shale formed while plastic and
subsequently fired.

- The manufacture of brick consists essentially of screening,
grinding, or working the clay to the desired consistency for
moulding, whether by hand or machine.

- After moulding, the bricks are dried and then burned in kilns for
many hours at high temperatures, approximately 2000 F.

- These processes purify the raw products, make it uniform and
homogeneous, burn out all combustible matter, and result in a
product which is both stable and physically permanent .

2. UNIT MASONRY

2.03 BRICKS

The types of bricks most frequently used in architecture are :

a. Common or building brick. Used for all
purposes, including facing.

b. Facing brick. Specially processed to give certain
specific surface characteristics. Used for
exposed masonry surfaces.

c. Glazed brick. These have a smooth outer
surface with a dull satin or high gloss finish. They
are load bearing, fire resisting, and impervious.
They are usually formed with vertical hollow
cores through the body with scoring on the back.

d. Fire (refractory) brick. These are ordinarily
made from a mixture of flint clay and plastic clay,
and are used for the lining of furnaces,
fireplaces, and chimneys.

2. UNIT MASONRY

2.03 BRICKS

BRICK WORK. The usual methods of laying brick are as follows :

a. Common Bond. Consists of five
stretcher courses and then a
header course. It is generally
begun with a row of headers at
the bottom course COMMON BOND

b. English Bond. Consists of
alternate courses of stretchers
and headers .

c. Flemish Bond. Consists of ENGLISH BOND

alternate headers and stretchers
in each course .

d. Herringbone. The bricks are
laid diagonally to form a herring-
bone pattern. FLEMISH BOND

2. UNIT MASONRY

2.03 BRICKS

Mortar joints
between brick
courses are
usually from
4.5mm (3/16”)
to 12mm (½”).

2. UNIT MASONRY

2.04 CONCRETE HOLLOW BLOCK

• Concrete Hollow Block (CHB) is a hollow masonry unit, with two
or three cells or cores, made of the following ingredients: water,
Portland cement, and various types of aggregate such as sand,
gravel, and crushed stone.

• Lightweight concrete hollow blocks are also manufactured with
such aggregates as cinders, expanded slag, expanded shale or
clay. Expanded blast furnace slag rates the highest in fire
resistance, and due to its cellular structure, has high sound and
thermal insulation quality.

• These are manufactured by machine-mixing the ingredients,
pouring the mix into molds, and curing the block by air drying. A
steam-and-pressure curing process is also used which can
produce concrete hollow block in a few hours.

2. UNIT MASONRY


• Standard CHB sizes are from
thicknesses of 100mm (4”), 150mm (6”)
and 200mm (8”) x height of 200mm (8”)
x length of 400mm (16”).

• CHB of 100mm (4”) thickness should
be used only for interior partition walls
where weather-tightness is not
required.

2. UNIT MASONRY


• The different types of concrete hollow block
include:

a. Stretchers c. Corner blocks e. Beam or lintel
blocks

b. Headers d. Jamb blocks

2. UNIT MASONRY


• Concrete hollow blocks should be laid on a full bed
of mortar with horizontal and vertical joints 10mm
(3/8”) thick.

• Reinforcement for 100mm (4”) and 150mm (6”)
thick wall shall be 10mm vertical bars at 600mm
on centers and 10mm horizontal bars every third
course.

• Reinforcement for 200mm (8”) thick walls shall be 12mm vertical bars
at 600mm on center and 12mm horizontal bars every third course.

• All horizontal reinforcement shall be tied to the vertical reinforcement at
their intersections.

• Dowel bars should be placed into the piers, columns, slabs, leaving 20
bar diameters exposed to splice with the reinforcement of the hollow
blocks.

2. UNIT MASONRY


• Block cells with reinforcement are filled with cement mortar.

• Concrete hollow block walls should have a reinforced concrete lintel
or beam block course every twelfth course; and a concrete column
stiffener at every 4.80 meters length.

2. UNIT MASONRY

2.05 “DURISOL” BLOCK

- “DURISOL” block is lightweight block
made from fiber and cement.

- “DURISOL” block units are two-core,
100mm (4”) or 150mm ( 6”) x 87mm (7-
1/2”) x 600mm (24”).

- Reinforcement shall be 10mm vertical
bars at 720mm (36”) on center and at
every 4th course. Every 4th course
should be a beam block course. Cores
shall be solidly filled with cement mortar.

2. UNIT MASONRY

2.06 PLASTER BLOCK

- also known as gypsum partition blocks, are usually made of gypsum,
vegetable fibers as binders, and reinforcement.

- used for lightweight, fire-resistant interior partitions and for furring and
fireproofing columns.

- Gypsum hollow blocks are manufactured in units of 75mm (3”), 100mm
(4”) or 150mm ( 6”) thicknesses, x 300mm (12”) height x 700mm (30”)
length.

- Gypsum solid block is manufactured only with a 50mm (2”) thickness.

2. UNIT MASONRY

2.07 STRUCTURAL CLAY TILE

- Structural clay tile are hollow masonry units, open at two ends with
interior webs or partitions 19mm (¾”) to 25mm (1”) dividing the block
into longitudinal cells.

- In its manufacture, the various shapes of clay tile are formed through
special dies and then wire-cut into the required lengths.

- It may have a smooth or scored (grooved) surface. Structural clay tile
is classified into:
a. Load-bearing wall tile. 300mm x
300mm x 300mm (12” x 12” x 12”)
b. Non-load bearing, fireproofing,
partition, and furring tile. 100mm
(4”) or 125mm (5”) x 200mm x
300mm

04 masonry

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