Timber roof

1.Lean to Roof 2.Collar Beam Roof 3.King Post Roof Truss 4.Queen Post Roof Truss

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 purlinroofs
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
■Atimberrooftrussisastructural
frameworkoftimbersdesignedtobridge
thespaceabovearoomandtoprovide
supportforaroof.
■Trussesusuallyoccuratregular
intervals,linkedbylongitudinaltimbers
suchaspurlins.Thespacebetween
eachtrussisknownasabay.
■Trussisbasicallyatriangleorarch
shapesframeusedthemajorityinroof
coverit.
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.
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Presentation By-Ar. Roopa Chikkalgi

5. ■Leantoroofisafreestandingstructure.Thewallofonesideoftheroomis
takenhigherthanthewallontheotherside.
■Lengthofthisroofissuitableformaximumspanof2.5meters.
■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 sheetand 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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Presentation By-Ar. Roopa Chikkalgi

6. Lean to Roof
6Presentation By-Ar. Roopa Chikkalgi

7. Collar Beam Roof
■Acollar beamorcollaris a horizontal member between two rafters and is very common in
domesticroof construction. Often acollaris 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. ■Collarbeamisusedtopreventspreadingthefootoftherafter.Whenthespanincreases,orwhen
theloadismore,theraftersofthecouplecloseroofhavethetendencytobend.Sointhis
condition,theraising-upofcollarbeamchecksthetendencyofsaggingduetofurtherincreasein
spanorexcessiveloadingconditions.
■Thiscollarbeamroofissuitableforthespanvaryingfromthe4to5.5m.Thisroofisusedfor
maximumspanof4.8m.
■Disadvantageofthiscollarroofisthattheheadofthewindowsformedinawallwillbesome
distancebelowceilingandgivelesspenetrationoflight.
■Sointhiscollarbeamroof,dormerwindowisprovidedwhichispartlybuiltintothewallandparty
intheroof.
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Presentation By-Ar. Roopa Chikkalgi

9. SHEET NO.1
■A1 SHEET ON Timber Lean to roof & Collared roof IN1:10 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 postis a central vertical postused in architectural or bridge
designs, taking tension to support a beam below from atrussabove.
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Presentation By-Ar. Roopa Chikkalgi

12. ■Inkingposttruss,purlinsaresupportedbyprincipalrafter.Thepurlinssupportthecloselyspaced
commonrafters.
■Theslopeofcommonraftersissameasthatofprincipalrafter.Thecommonrafterssupporttheroof
covering.
■InkingPostRooftruss,TheBottomchordofthetrussisactastiebeamandthistiebeamreceivesthe
endsoftheprincipalraftersandpreventsthewallfromspreadingoutduetothrust.
■Theverticalkingpostisusedtopreventthesaggingoftiebeamatcentreofspan.TheStrutsare
connectedtothetiebeamsandtheprincipalraftersininclineddirection.TheStrutsareusedtoprevent
thesaggingofprincipalrafters.
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13. Presentation By-Ar. Roopa Chikkalgi 13
•Ridgebeamisprovidedattheapexoftherooftoprovideendsupportofthecommonrafters.Thetrusses
aresupportedonthebedblocksofstoneorconcretewhichisfixedinthesupportingwalls.
•TheSpacingofKingPosttrussislimitedto3mcentretocentre.Thetrussissuitableforspansvarying
from5to8meter.
•Itisnotsuitableforlongspan.
•Thekingposttrussdoesnotprovidestoragespace,becausetheframesareusuallyexposedanddoesnot
allowextraroom.
•Kingposttrussisusedwhenthereisaneedtosupporttheweightofanexpansiveroof.
•Thisroofprovidesnotonlyfunctionally,butalsoaddsbeautyaswell.
•Thekingposttrussisalsousedforsimplerooflinesandshortspanbridges.

14. SHEET NO.2
■A1 SHEET ON King post roof IN1:10 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 apitched roofsupport using two
verticaltieposts connected between thetie beamand therafters
QueenPost Roof Truss
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Presentation By-Ar. Roopa Chikkalgi

16. ■Thewoodenqueenpostroofdiffersfromaking-posttrussinhavingtwowoodenuprightsorvertical
memberwhichisknownasqueenpost.Inthisroof,Queen–postsisusedinsteadofkingpost.
Inthisroof,TheQueenpostsarethetensionmemberswhichareusedtopreventthesaggingoftie
beam.
Astrainingsillisfixedonthetiebeamandalsofixedbetweenthefeetofqueenpost.Thisstraining
sillisusedforreducingthethrustsfromstruts.Theprincipalrafters,Strainingbeams,strutsand
strainingsillareincompressionwhereasthequeenpostsandtiebeamareintension.
Purlinsarehorizontalwoodenmemberslaidonprincipalraftersonwall-to-walltosupportcommon
rafterofaroofwhichisfixedwithcleat.
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•Queenposttrussesaresuitablefor8to12meters.
•Thesetrussesaremadefromavarietyofmaterialssuchastimberorsteel.
•TheQueenposttrussissimplerandlighterinweight.Itdoesnotputweightonthecentreofthe
maintiebeam,asthekingposttruss.
•Queenposttrussesareusedwhenthereisaneedtocoverlargeareas.
•Theyarerelativelylow-costandcanbemadetofitalmostanysizeorslopeofroof.
•Itcanalsoprovidestrikingceilingdesignthatdifferentiatesahome.
Presentation By-Ar. Roopa Chikkalgi

18. SHEET NO.3
■A1 SHEET ON Queen post roof IN1:10 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 posthas a central vertical postas used in
architectural or bridge designs, working in tension to
support a beam below from atrussapex above.
Queen Post truss is define as apitched roofsupport using
two verticaltieposts connected between thetie beamand
therafters.
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.
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Presentation By-Ar. Roopa Chikkalgi