This document discusses different types of timber roof structures. It describes lean-to roofs, which consist of rafters sloping on one side and are supported by a single wall. Collared roofs have a horizontal collar beam placed between rafters to prevent their spreading. King post roofs contain a central vertical post to support the tie beam below. Queen post roofs are similar but use two vertical queen posts instead of a single king post. Details and dimensions are provided for each type of roof.

1. TIMBER ROOF
a) Lean to roof
b) Collared Roof
c) King post roof
d) Queen Post Roof
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Presentation By- Ar. Roopa Chikkalgi

2. Classification of Roof
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Roof is classified as per functional requirements. The
roofs are mainly classified into three types.
•Pitched or Sloping Roof
•Flat Roof or Terrace Roof
•Shell Roofs or curved Roof
a) Single roofs
• Lean-to-roof
• Couple roof
• Couple-close roof
• Collar-beam roof or collar tie
b) Double or purlin roofs
c) Triple-Membered or Framed or Trussed Roof
•King-post roof Truss
•Queen-post roof Truss
•Combinations of King-post and Queen-post Trusses
•Mansard roof Truss
•Truncated roof Truss
•Belfast roof Truss
•Composite roof Trusses
•Steel sloping roof Trusses
Presentation By- Ar. Roopa Chikkalgi

3. TIMBER ROOF
■ A timber roof truss is a structural
framework of timbers designed to bridge
the space above a room and to provide
support for a roof.
■ Trusses usually occur at regular
intervals, linked by longitudinal timbers
such as purlins. The space between
each truss is known as a bay.
■ Truss is basically a triangle or arch
shapes frame used the majority in roof
cover it.
3Presentation By- Ar. Roopa Chikkalgi

4. Lean to Roof
■ The lean to roof is defined as single slope roof with its upper edge adjoining a wall or
building.
■ This is the simplest type of pitched roof consisting of rafters sloping on one side only.
4Presentation By- Ar. Roopa Chikkalgi

5. ■ Lean to roof is a free standing structure. The wall of one side of the room is
taken higher than the wall on the other side.
■ Length of this roof is suitable for maximum span of 2.5 meters.
■ This lean to roof is constructed against an existing wall or other roof.
■ Main use of this roof is for constructing sheds, simple extensions, car ports,
for covering verandahs, etc. When any storage building will require additional
space than the lean to roof is constructed with existing wall.
■ Construction of lean to roof is easy and inexpensive.
■ Due to slope of the roof, water and snow easily run off and reduces
necessary extra waterproofing.
■ So this roof is best for constructing in high rain fall and snow fall regions.
This may be done either as a part of original construction or even during
execution after some year.
■ In this roof, the roof covers may be of Mangalore tiles, A.C sheets or even
pre-coated sheet and this roofing sheet also add beauty to the structure
apart from it functional use.
■ This roof is not adequate for a long span where its width is more as
minimum clearance of 2.0 m to 2.5 m at eaves level is needed.
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6. Lean to Roof
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7. Collar Beam Roof
■ A collar beam or collar is a horizontal member between two rafters and is very common in
domestic roof construction. Often a collar is structural but they may be used simply to frame a
ceiling.
■ In this Roof, Horizontal tie is raised up from the feet of the rafters to almost middle of the rafters.
This raised up horizontal tie is known as the collar Beam. Collar beam should not be fixed more
than one-third or one- half of the rise of the roof up from the wall plate.
7Presentation By- Ar. Roopa Chikkalgi

8. ■ Collar beam is used to prevent spreading the foot of the rafter. When the span increases, or when
the load is more, the rafters of the couple close roof have the tendency to bend. So in this
condition, the raising-up of collar beam checks the tendency of sagging due to further increase in
span or excessive loading conditions.
■ This collar beam roof is suitable for the span varying from the 4 to 5.5m. This roof is used for
maximum span of 4.8 m.
■ Disadvantage of this collar roof is that the head of the windows formed in a wall will be some
distance below ceiling and give less penetration of light.
■ So in this collar beam roof, dormer window is provided which is partly built into the wall and party
in the roof.
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Presentation By- Ar. Roopa Chikkalgi

9. SHEET NO.1
■ A1 SHEET ON Timber Lean to roof & Collared roof IN 1:10 SCALE
■ With one Interesting detail of the joinery for each roof type in 1:5 Scale.
9Presentation By- Ar. Roopa Chikkalgi

10. Presentation By- Ar. Roopa Chikkalgi 10

11. King Post Roof Truss
■ Truss is basically a triangle or arch shapes frame in roof to cover it.
■ A King post is a central vertical post used in architectural or bridge
designs, taking tension to support a beam below from a truss above.
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Presentation By- Ar. Roopa Chikkalgi

12. ■ In king post truss, purlins are supported by principal rafter. The purlins support the closely spaced
common rafters.
■ The slope of common rafters is same as that of principal rafter. The common rafters support the roof
covering.
■ In king Post Roof truss, The Bottom chord of the truss is act as tie beam and this tie beam receives the
ends of the principal rafters and prevents the wall from spreading out due to thrust.
■ The vertical king post is used to prevent the sagging of tie beam at centre of span. The Struts are
connected to the tie beams and the principal rafters in inclined direction. The Struts are used to prevent
the sagging of principal rafters.
12Presentation By- Ar. Roopa Chikkalgi

13. Presentation By- Ar. Roopa Chikkalgi 13
• Ridge beam is provided at the apex of the roof to provide end support of the common rafters. The trusses
are supported on the bed blocks of stone or concrete which is fixed in the supporting walls.
• The Spacing of King Post truss is limited to 3 m centre to centre. The truss is suitable for spans varying
from 5 to 8 meter.
• It is not suitable for long span.
• The king post truss does not provide storage space, because the frames are usually exposed and does not
allow extra room.
• King post truss is used when there is a need to support the weight of an expansive roof.
• This roof provides not only functionally, but also adds beauty as well.
• The king post truss is also used for simple roof lines and short span bridges.

14. SHEET NO.2
■ A1 SHEET ON King post roof IN 1:10 SCALE
■ With two Interesting details of the joinery for the roof type in 1:5 Scale.
14Presentation By- Ar. Roopa Chikkalgi

15.  Truss is basically a triangle or arch shapes frame used majority in roof
cover it.
 Queen Post truss is defined as a pitched roof support using two
vertical tie posts connected between the tie beam and the rafters
Queen Post Roof Truss
15Presentation By- Ar. Roopa Chikkalgi

16. ■ The wooden queen post roof differs from a king-post truss in having two wooden uprights or vertical
member which is known as queen post. In this roof, Queen – posts is used instead of king post.
 In this roof, The Queen posts are the tension members which are used to prevent the sagging of tie
beam.
 A straining sill is fixed on the tie beam and also fixed between the feet of queen post. This straining
sill is used for reducing the thrusts from struts. The principal rafters, Straining beams, struts and
straining sill are in compression whereas the queen posts and tie beam are in tension.
 Purlins are horizontal wooden members laid on principal rafters on wall-to-wall to support common
rafter of a roof which is fixed with cleat.
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17. 17
• Queen post trusses are suitable for 8 to 12 meters.
• These trusses are made from a variety of materials such as timber or steel.
• The Queen post truss is simpler and lighter in weight. It does not put weight on the centre of the
main tie beam, as the king post truss.
• Queen post trusses are used when there is a need to cover large areas.
• They are relatively low-cost and can be made to fit almost any size or slope of roof.
• It can also provide striking ceiling design that differentiates a home.
Presentation By- Ar. Roopa Chikkalgi

18. SHEET NO.3
■ A1 SHEET ON Queen post roof IN 1:10 SCALE
■ With two Interesting details of the joinery for the roof type in 1:5 Scale.
18Presentation By- Ar. Roopa Chikkalgi

19. King Post Roof Truss Queen Post Roof Truss
A king post has a central vertical post as used in
architectural or bridge designs, working in tension to
support a beam below from a truss apex above.
Queen Post truss is define as a pitched roof support using
two vertical tie posts connected between the tie beam and
the rafters.
The king post roof truss consists following components:
Tie Beam
Two Inclined principal rafter
Two struts
King post
Ridge Beam
The Queen post Truss consists of following components.
Two Queen posts
Two Principal Rafters
Struts
Tie Beam
Straining beams
Straining sills
Purlins
King post roof truss is used when the length of span is in
the range of 5 to 8 m.
Queen post roof truss is used when the length of span is
in the range of 8 to 12 m.
One vertical post is provided at the centre of the roof
which is called king post.
Two vertical posts are provided in 2 sides at distance
which is called queen post.
Straining beam and straining sill are not necessary. Straining beam and straining sill are used to keep the
queen post in stable position.
King-post is connected with principal rafter, strut and tie
beam.
Queen-post is connected with principal rafter, strut,
Straining beam, straining sill and tie beam.
The top ends of two main rafters are connected to ridge
pitch.
Top ends of two main rafters are joined with the queen
posts heads. 19
Presentation By- Ar. Roopa Chikkalgi