This document discusses different types of roofs and roofing materials. It defines a roof as a covering that protects a building from rain, sun, wind and other elements. Roof type depends on climate and available materials, and should be strong, durable, waterproof and provide insulation. Pitched roofs are suitable for heavy rainfall areas while flat roofs work for dry, hot regions. Various terms related to pitched roofs like span, rise, pitch, eaves and ridge are explained. Common materials include thatch, wood, tiles, slates, asbestos sheets, galvanized iron sheets and newer options like fiber sheets. Advantages and disadvantages of flat roofs are also outlined.

1. Roof and roofing material

2. Roof- definition ,necessity and
purpose
• Definition- is defined as a covering provided over
the top of a building with a view to keep out
rain,sun ,wind to protect the building from the
adverse effects of these elements.
• Roof covering is supported on a structure on
building top.
• The structural element may be truss,dome, flat
slab ,shell or frame .
• Roof covering may be thatch,wooden
single/planks,tiles,slates,AC sheets, GI sheets.

3. Selection of type of roof
• Depends upon the climatic conditions,availability
of selected materials at site.
• Requirements of well planned roof- 1) should
strong to carry anticipated dead and live loads
safely. 2) should be durable against adverse
effects of rain,snow,sun,wind. 3) should have
efficient waterproofing and drainage provisions
(slope) 4)should insulation against
temperature(heat) and sound.

4. Classification of roof
• Pitched roof-suitable in coastal region of heavy
rain fall,snow fall.
• Flat or terraced roof- for buildings in plains or in
hot regions where rainfall is scanty.
• Some times roof other than pitched or flat to
meet the functional as well as asthetical
requirement is provided.
• For eg .- 1) domes- large circular halls,assembly
,gymnassium 2)libraries,theatres,recration
hall,factories-shell roof of folded roof.

5. Terms used in pitched roof
• Span –the clear distance between the supports of
an arch,beam or roof truss.
• Rise of roof- it is the vertical distance between
wall plate and the top of the ridge.
• Pitch of the roof-the inclination of the sides of a
roof to the horizontal.
• Eaves-The lower edge of the inclined roof surface
of a pitched roof.
• Ridge - the apex of the angle formed by
termination of the inclined surface at the top of a
slope.

8. Terms used in pitched roof cotd…
• Ridge piece/beam/board-horizontal timber piece
provided at the apex of the roof truss.common
rafters are fixed to this piece and supported by it.
• Valley- the acute angle or gutter formed by the
intersection of two slopes in pitched roof.
• Hip-the ridge formed by the intersection of two
sloped surfaces having an exterior anglr greater
than 180 .
• Hipped end- the sloped triangular surface formed
at the end of a roof.

11. Terms used in pitched roof cotd…
• Gable-the triangular portion of the end wall of sloped
roof formed by continuing the end wall up withinn the
roof.
• Verge-the edge of the sheets,slates or tiles projecting
beyound the gable of the sloped roof.
• Barge board – it is the timber board used to hold the
common rafters forming verge.
• Eaves board or facia board-it is a wooden plank usually
25 mm thk and 15 cm wide fixed along the eaves
connecting the feet of the common rafters.
•

15. Terms used in pitched roof cotd…
• Common rafter- these are inclines wooden
members laid from the ridge to the eaves. They
are bevelled against the ridge piece at the head
and are fixed to purlins at the intermediate
points.they are spaced 30 to 45 cm apart.
• Purlins- these are horizontal members of wood or
steel used to support common rafters.
• Cleats –these are short sections of wood or steel,
nailed screwed or bolted to the rafters of the
truss for supporting purlins.
•

17. Terms used in pitched roof cotd…
• Wall plate-timber pieces which are provided
over the top of a stone or brick wall for the
purpose of fixing the feet of the common
rafters.

18. Wall plate

19. Cotd…
• Template- this is a block of stone or concrete
provided under the end of the tie beam to
spread the load from the roof over a large
area of bearing.
• Hip rafter- these are the rafters which form
the hip of a sloped roof.these run from the
ridge to corners of the wall to support the
covering over the hip.they also receive the
ends of purlins and jack rafters.

20. Hip and jack rafters

21. Valley rafter
• Valley rafter –these are the rafters provided at
the slope to support the valley gutters.
• Post plates-
• Battens –small scantlings which are nailed to
the rafters for laying tiles over the sloped roof.

26. • https://youtu.be/L2iXgby0Ffg -king post Vs
queen post truss
• https://youtu.be/fppMs_fl4ag- king post truss
very imp video
• https://youtu.be/czH4MqWkFGc- couple roof

27. Lean to Roof

28. RCC, Mangalore Tiles, AC Sheets, G.I. and Painted Corrugated G.I.
Sheets, Plastic and Fiber Sheets.

29. Flat roof
• A roof is said to be flat if it laid at an angle less than 100
to horizontal.
• May be of RCC,precast,flag stones supported on rolled
steel joists.
• Efficient waterproofing and drainage arrangements is
very imp. For flat roof
• An additional layer of insulating material is provided(
mud) for thermal insulation.(this layer is known as
terracing or grading)
• In case of RCC slab slope of 1 in 40 to 60 is desirable
for proper drainage.
•

30. Advantages of flat roof
• The roof can be convienientlyused as terrace for
playing gardening or sleeping.
• It is easy to tender flat roof fire resistant.
• It avoids the enclosure of triangular space.
• Good insulating properties.
• Construction is more simpler and architecturally
suitable.
• For multistoried building it is an best option.
• Flat roofs require lesser area of roofing material
than sloped roofs.

31. Disadvantage of flat roof
• The span is restricted as it can not be provided over
large span unless coumns and beams are provided.
• Self weight of the flat roof is considerable which makes
the construction more expensive.
• Flat roof are exposed to sun and rain may lead to
cracks.
• Difficult to trace out and rectify leaks.
• Initial cost is more.
• Progress of construction of flat roof is less than pitched
roof.

32. Manglore tiles

33. shingles

34. Roof with wood shingles

35. Asbestos-cement sheets as roof
covering

36. TRAFFORD SHEETS

37. CORRUGATED SHEETS

38. FIBRE SHEETS