Roof

1. Ar.Anurag Khandelwal
Roofs

2. Roof is the covering on the uppermost part of a building. A roof protects the building and
its contents from the effects of weather.
Structures that require roofs range from a letter box to a cathedral or stadium, dwellings
being the most numerous.
A roof protects primarily against rain. against heat, against sunlight, against cold and against
wind.
What is The Roof

3. Roofing Terminology

4. Roofing Terminology
Valley
The less-than 180-degree angle where two sloping roof sections
come together.
Hip
The external angle at the junction of two sides of a roof whose supporting walls a adjoin.
Joist
In a flat roof, a horizontal structure member over which sheathing is nailed.
Rafter
A structural member (usually slanted) to which sheathing is nailed.
Flashing
Sheet metal or other material used at junctions of different planes on a roof to
prevent leakage.
Gable
The triangular upper part of a wall closing the end of
a ridged roof.
Ridge
The horizontal line at the top edge of two sloping roof
planes.

5. Roofing Terminology
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Drip
The strip of metal extending out
beyond the eaves or rakes to prevent
rainwater from rolling around the
shingles back onto the wooden
portion of the house.
Fascia
Trim board behind the gutter and
eaves.
Shingle Flashing
Flashing that is laid in strips under
each shingle and bent up the edge of a
chimney or wall
Underlayment
The material (usually roofing felt) laid on top of sheathing before shingles are applied.
Soffit
The boards that enclose the underside of that portion of the roof which extends out beyond
the sidewalls of the house.

13. Roof Types
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Flat
Shed
Gable
Hip
Dutch Hip
Gambrel
Mansard
Butterfly
Dome

14. Flat
A flat roof is covering which is at zero degree
inclination.

15. Shed
A shed roof is basically a flat roof with a slightly greater angle allowing
for greater runoff. They are relatively easy to build and inexpensive as
compared to most other roof types. They are usually used on home
extension rooms and porches

16. Gable
A gable roof consists of two shed roof structures joined at the peak
forming a ridge line.

17. Dormers are room construction extensions from the roof structure.
They usually have windows or doors on the front wall structure.
Dormers are often used in 1 ½ story construction to provide light and
ventilation to the upper story.
Gable Dormers

18. Hip
A hip roof is a gable roof with angled ends taking the place of the gable
end of the structure.

19. Dutch Hip
A Dutch roof design is a hip roof with small gable ends at the ridge
allowing for attic ventilation

20. Gambrel
Gambrel roof design is similar to gable construction With two angles
on each side. Steep lower surfaces and shallow angle top surfaces allow
greater floor space in 1 ½ story construction

21. Mansard
Mansard roof construction consists of a compound hip roof design with
a lower and upper hip format.

22. Butterfly
The butterfly roof is an inverted gable roof design creating a central
valley for runoff. The design is visually stunning but impractical for water
tightness.

23. Dome
Dome construction is one of the most
difficult to build but is often the most
interesting visually
Geodesic roof construction
consists of triangular framing
placed together to form a dome.
These structures have surprising
strength and visual interest.
Geodesic

24. Types of roof structure
Flat roof
Pitch roof
Space frame
Roof shell
Folded plate
Tensile structure

25. 1. Flat roof
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A roof is designated as flat if its
slope is less than ten degrees. Slope
less than 3:12 or 25 percent
Flat roofs have traditionally been
used in hot climates where water
accumulation is not a problem.
Structural decks ordinary used
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Wood panels over wood joist
Solid wood decking over heavy
timber framing
Corrugated steel decking
Sitecast concrete slab
Precast concrete slab
Panels of wood fibre bonded
together with portland cement
etc

26. ELEMENTS OF FLAT
ROOF
Concrete
gutter
Steel decking
concrete
Lines indented for expansion
caused by heat and easy to flatten
the roof in a uniform manner to
prevent any pool of water after
rain.
parapet

27. Water pool formed due to
poor workmanship
PROBLEMS OF LEAKING
ON FLAT ROOF

28. Weatherproofing the roof
The flat roof relied on some kind of membrane for keeping
moisture out. In dry climates this is done with clay tiles, butin
Canada asphalt, or rubber is necessary.
CONCRETE, TIMBER OR STEEL STRUCTURE
Waterproof layer and insulation
Cement screed
Finishes
 Flat roofs are never actually flat, a subtle slope directs
standing moisture to drains at edges, or inside.

29. Advantages Disadvantages of Flat roof
Design:
 No space lost below roof, i.e. no dead
space Less material is used than in a
sloped roof
 The rooftop is potentially useful as a terrace, or sleeping
porch Potentially pleasing appearance
 Easier to build than a sloped roof
 Advantages:
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 Disadvantages:
 Roof elements can not overlap, hence waterproofing must be
more complex, and more thorough
 Drainage is not automatic
 Support of snow load must be insured

30. Pitched Roof
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pitched roof is a roof structure where
the roof leans to one side of the house.
It is also known as lean-to roof.
The rafters are connected to the
highest wall and then it is inclined to a
lower wall, which then forms the
pitched roof.
The rafters are often connected into
the wall individually or even supported
on a wall plate bedded within the wall.

31. column
wall
columns
walls
A mono-pitched roof structure
A lean-to roof structure
A pitched roof
Pitched Roof Types

32. flashing
openings
SUNSHADING
wall
column
flashing
The Components

33. Roof Framing Plan

34. Terminology

35. Roof Terms
PITCHED ROOF
Waterproofing
layer and
insulation
Timber batten
Finishes:
Clay tiles or
Cement tiles
Metal decking
Ceiling

36. Calculating Pitch
 Roof with a pitch of 3:12 (25 percent) or greater called Steep
roof

37. PITCHED ROOF: TIMBER
STEEL
- truss
- truss
Truss built as from
individual members
Truss fabricated from factory
Whole roof structure built from
steel
Gang nails
Truss fabricated from factory
steel

38. rivetted
Placement of roof clay tiles as seen from below

39. ROOFING MATERIALS
  Roofing material is the outermost layer on the
roof of a building, sometimes self- supporting,
but generally supported by an underlying
structure. A building's roofing material provides
shelter from the natural
 elements, and insulation against heat and cold. The
outer layer of a roof shows great variation dependent
upon availability of material, and the nature of the
supporting structure.

40.  Thatch - roofing made of
plant stalks in overlapping
layers.
 Wheat straw - Widely used
in England, France and other
parts of Europe.
 Seagrass – Has a longer life that
straw.
 Rye straw – Most commonly
used in Europe.
ROOFING MATERIALS

41. ROOFING MATERIALS
 Shingles - the generic term for
a roofing material that is in
many overlapping sections,
regardless of the nature of the
material.
 Red Cedar - Life expectancy is
up to 30 years. High cost.
 Hardwood – Very durable
roofing found in
Colonial Australian architecture.

42.  Slate - High cost with a life
expectancy of up to 200 years.
 Stone Slab - Stone slabs
require a very heavyweight
roof structure, but their weight
makes them stormproof. An
obsolete roofing material, now
used commercially only for
building restoration.
ROOFING MATERIALS

43.  Ceramic tile - High cost, life of
more than 100 years.
 Imbrex and tegula - style dating
back to ancient Greece and
Rome.
 Monk and Nun - a style similar
to Imbrex and tegula, but
basically using two Imbrex tiles.
ROOFING MATERIALS

44.  Copper Sheet - Sheet copper
used as roofing is lighter than
wooden shingles and much
lighter than slate, tile, or lead.
 Metal shakes or shingles - Long
life. High cost, suitable for roofs
of 3/12 pitch or greater. Because
of the flexibility of metal, they
can be manufactured to lock
together, giving durability and
reducing assembly time.
ROOFING MATERIALS

45.  Mechanically seamed metal -
Long life. High cost, suitable for
roofs of low pitch such as 0.5/12
to 3/12 pitch.
 Concrete - usually reinforced
with fibers of some sort.
 Asphalt shingle - Cheaper than
slate or tiles. Various life span
expectancies
ROOFING MATERIALS

46.  Asphalt laminate shingles -
are beginning to replace
traditional asphalt shingles.
Laminates are thicker, heavier,
more wind resistant, and
appear three-dimensional.
 Asbestos shingles - Very long
lifespan, fireproof and low cost
but now rarely used because
of health concerns.
ROOFING MATERIALS

47.  Membrane roofing - Membrane
roofing is in large sheets,
generally fused in some way at
the joints to form a continuous
surface.
 Thermoset membrane (e.g. EPDM
rubber) - Primary application is big
box store with large open areas
 Thermoplastic (e.g. PVC, TPO, CSPE
) - Lends itself well to both big box
and small roof application because
of its hot air weld ability.
ROOFING MATERIALS

48.  Modified bitumen – heat-welded,
asphalt-adhered or installed with
adhesive. Lends itself well to most
applications.
 Built-up roof – Typically covered with a
thick coat of the water-proofing
material and covered with gravel. The
gravel provides protection from ultra-
violet degradation, stabilizes the
temperature changes, protects surface
of the roof and increases the weight of
the roof system to resist wind blow-off.
ROOFING MATERIALS

49.  Metal roofing
 Galvanized steel - frequently
manufactured with wavy corrugations
to resist lateral flexing and fitted with
exposed fasteners. Widely used for low
cost and durability.
 Copper roofs - can last for hundreds
of years. They offer durability, ease
of, fabrication, low maintenance
corrosion resistance, low thermal
movement, lightning protection,
radio frequency shielding, low
lifetime costs, and are 100%
ROOFING MATERIALS

50. ROOF FINISHES
PATTERNED CLAY ROOF
TILES
CLAY ROOF TILES
TATCH

51. ASBESTOS
PATTERNED STEEL
DECKING 2
PATTERNED STEEL
DECKING 1

52. ASPHALT WOOD
SLATEMATEL

53. A space frame or space structure is a truss-like, lightweight rigid structure
constructed from interlocking struts in a geometric pattern. Space frames usually
utilize a multidirectional span, and are often used to accomplish long spans with few
supports. They derive their strength from the inherent rigidity of the triangular frame;
flexing loads (bending moments) are transmitted as tension and compression loads
along the length of each strut.
3. Space frame

54. 4.Dome
A dome is a structural element of
architecture that resembles the hollow upper
half of a sphere. Dome structures made of
various materials have a long architectural
lineage extending into prehistory.

55. A thin shell is defined as a shell with a thickness
which is small compared to its other dimensions and
in which deformations are not large compared to
thickness. A primary difference between a shell
structure and a plate structure is that, in the
unstressed state, the shell structure has curvature
as opposed to plates structures which are flat
4. ROOF SHELL

56. Its an roof which has been moulded to an shape. which is in rcc,
steel etc.its for large covering for open spaces
5. FOLDED PLATE ROOF

57. A tensile structure is a construction of elements carrying only tension and no
compression or bending. The term tensile should not be confused with
tensegrity, which is a structural form with both tension and compression
elements.
6. Tensile structure

58. The CribPost System
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The CribPost System is best described as a series of
temporary hydraulic shoring posts that can be
continuously extended with the intent to lift a roof to a
higher elevation.
Main Features
 CribPosts can be extended to any desired elevation.
 CribPosts can be clustered to obtain higher lifting
capacities.
 The roof is monitored by laser instruments to
maintain close tolerances.
 Lateral stability is maintained and adjusted through
ROOFLIFTERS’ unique guying system.
 The entire roof can be lifted in a single section using
ROOFLIFTERS’ multi-point synchronization system.

61. What Are Green Roofs?
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A green roof is a roof of
a building that is partially or
completely covered with
vegetation and soil, or a growing
medium, planted over a
waterproofing membrane.
It may also include additional
layers such as a root barrier and
drainage and irrigation systems.
also known as vegetated roof
covers, eco-roofs or nature roofs.
water quality by filtering,
absorbing or detaining
rainfall. Green Roofs Are Great
for These Things ,great for the
environment.
On the green roof of the Mountain Equipment
Co-op store in Toronto, Canada.

62.  When the bottom
chord of the truss
extends beyond the
exterior wall,
additional insulation
may be added.
ROOF INSULATION

63. ROOF INSULATION

64. ROOF INSULATION MATERIALS
 Wood fiber –
 Perlite -
 Polyisocyanurate –
 Expanded Polystyrene -

65. ROOF INSULATION MATERIALS
 Extruded Polystyrene –
 Cellular Glass -
 Gypsum Board