broken hip roof
DESCRIPTION
Broken Hip Roof. Lay out of Broken Hip Roof. Roof Pitch = 25⁰. No new bevels need to be developed. Lay out of Broken Hip Roof. Roof Pitch = 25⁰. All Bevels and edge cuts are the same as a hip roof Broken Hip As Span is not the same the rise will not be the same. - PowerPoint PPT PresentationTRANSCRIPT
Broken Hip Roof
Lay out of Broken Hip RoofRoof Pitch = 25⁰
No new bevels need to be developed
Lay out of Broken Hip RoofRoof Pitch = 25⁰
All Bevels and edge cuts are the same as a hip roof
Broken Hip As Span is not the same the rise will not be the same
Lay out of Broken Hip RoofRoof Pitch = 25⁰
Rafter 90 x 35 @ 450 c to cHip Rafters 140 x 35Ridge 140 x 35
Common Rafter Major Span
Common Rafter Minor Span
Hip Rafter Major Span
Hip Rafter Minor Span
Valley Rafter Minor Span
Crown End Major Span
Crown End Minor Span
Centring Rafter Major Span
Centring Rafter Minor Span
Crippled Centring RafterBroken Hip
Gathering Point
Lay out of Broken Hip RoofRoof Pitch = 25⁰
Determine Centreline LengthCommon Rafter Major Span =
Rafter 90 x 35 @ 450 c to cHip Rafters 140 x 35Ridge 140 x 35
1000/ Cos 25 =
Lay out of Broken Hip RoofRoof Pitch = 25⁰
Determine Centreline LengthCommon Rafter Major Span =1103
Rafter 90 x 35 @ 450 c to cHip Rafters 140 x 35Ridge 140 x 35
Lay out of Broken Hip RoofRoof Pitch = 25⁰
Determine Centreline LengthCommon Rafter Major Span = 1103Common Rafter Minor Span =
Rafter 90 x 35 @ 450 c to cHip Rafters 140 x 35Ridge 140 x 35
675/ Cos 25 =
Lay out of Broken Hip RoofRoof Pitch = 25⁰
Determine Centreline LengthCommon Rafter Major Span = 1103Common Rafter Minor Span = 745
Rafter 90 x 35 @ 450 c to cHip Rafters 140 x 35Ridge 140 x 35
Lay out of Broken Hip RoofRoof Pitch = 25⁰
Determine Centreline LengthCommon Rafter Major Span = 1103Common Rafter Minor Span = 745Rise Main Roof =
Rafter 90 x 35 @ 450 c to cHip Rafters 140 x 35Ridge 140 x 35
Tan 25 x 1000 =
Lay out of Broken Hip RoofRoof Pitch = 25⁰
Determine Centreline LengthCommon Rafter Major Span = 1103Common Rafter Minor Span = 745Rise Main Roof = 466
Rafter 90 x 35 @ 450 c to cHip Rafters 140 x 35Ridge 140 x 35
Tan 25 x 1000 =
Lay out of Broken Hip RoofRoof Pitch = 25⁰
Determine Centreline LengthCommon Rafter Major Span = 1103Common Rafter Minor Span = 745Rise Main Roof = 466Rise Minor Roof =
Rafter 90 x 35 @ 450 c to cHip Rafters 140 x 35Ridge 140 x 35
Tan 25 x 675 =
Lay out of Broken Hip RoofRoof Pitch = 25⁰
Determine Centreline LengthCommon Rafter Major Span = 1103Common Rafter Minor Span = 745Rise Main Roof = 466Rise Minor Roof = 315
Rafter 90 x 35 @ 450 c to cHip Rafters 140 x 35Ridge 140 x 35
Lay out of Broken Hip RoofRoof Pitch = 25⁰
Determine Centreline LengthCommon Rafter Major Span = 1103Common Rafter Minor Span = 745Rise Main Roof = 466Rise Minor Roof = 315Hip Length Major Span =
Rafter 90 x 35 @ 450 c to cHip Rafters 140 x 35Ridge 140 x 35
=√(Rafter² + ½ Span²) √(1.103² + 1²)= 1.489
Lay out of Broken Hip RoofRoof Pitch = 25⁰
Determine Centreline LengthCommon Rafter Major Span = 1103Common Rafter Minor Span = 745Rise Main Roof = 466Rise Minor Roof = 315Hip Length Major Span = 1.489
Rafter 90 x 35 @ 450 c to cHip Rafters 140 x 35Ridge 140 x 35
Lay out of Broken Hip RoofRoof Pitch = 25⁰
Determine Centreline LengthCommon Rafter Major Span = 1103Common Rafter Minor Span = 745Rise Main Roof = 466Rise Minor Roof = 315Hip Length Major Span = 1.489Hip Length Minor Span =
Rafter 90 x 35 @ 450 c to cHip Rafters 140 x 35Ridge 140 x 35
=√(Rafter² + ½ Span²) √(0.745² + 0.500²)= 0.897
Lay out of Broken Hip RoofRoof Pitch = 25⁰
Determine Centreline LengthCommon Rafter Major Span = 1103Common Rafter Minor Span = 745Rise Main Roof = 466Rise Minor Roof = 315Hip Length Major Span = 1.489Hip Length Minor Span = 0.897
Rafter 90 x 35 @ 450 c to cHip Rafters 140 x 35Ridge 140 x 35
Lay out of Broken Hip RoofRoof Pitch = 25⁰
Determine Centreline LengthCommon Rafter Major Span = 1103Common Rafter Minor Span = 745Rise Main Roof = 466Rise Minor Roof = 315Hip Length Major Span = 1.489Hip Length Minor Span = 0.897Hip Rise Major Span =
Rafter 90 x 35 @ 450 c to cHip Rafters 140 x 35Ridge 140 x 35
=Same as Rise Major Span
Lay out of Broken Hip RoofRoof Pitch = 25⁰
Determine Centreline LengthCommon Rafter Major Span = 1103Common Rafter Minor Span = 745Rise Main Roof = 466Rise Minor Roof = 315Hip Length Major Span = 1.489Hip Length Minor Span = 0.897Hip Rise Major Span = 466
Rafter 90 x 35 @ 450 c to cHip Rafters 140 x 35Ridge 140 x 35
Lay out of Broken Hip RoofRoof Pitch = 25⁰
Determine Centreline LengthCommon Rafter Major Span = 1103Common Rafter Minor Span = 745Rise Main Roof = 466Rise Minor Roof = 315Hip Length Major Span = 1.489Hip Length Minor Span = 0.897Hip Rise Major Span = 466Hip Rise Minor Span =
Rafter 90 x 35 @ 450 c to cHip Rafters 140 x 35Ridge 140 x 35
=Same as Rise Minor Span
Lay out of Broken Hip RoofRoof Pitch = 25⁰
Determine Centreline LengthCommon Rafter Major Span = 1103Common Rafter Minor Span = 745Rise Main Roof = 466Rise Minor Roof = 315Hip Length Major Span = 1.489Hip Length Minor Span = 0.897Hip Rise Major Span = 466Hip Rise Minor Span = 315
Rafter 90 x 35 @ 450 c to cHip Rafters 140 x 35Ridge 140 x 35
Lay out of Broken Hip RoofRoof Pitch = 25⁰
Determine Centreline LengthCommon Rafter Major Span = 1103Common Rafter Minor Span = 745Rise Main Roof = 466Rise Minor Roof = 315Hip Length Major Span = 1.489Hip Length Minor Span = 0.897Hip Rise Major Span = 466Hip Rise Minor Span = 315Creeper Shortening =
Rafter 90 x 35 @ 450 c to cHip Rafters 140 x 35Ridge 140 x 35
= 450/Cos 25= 497
Lay out of Broken Hip RoofRoof Pitch = 25⁰
Determine Centreline LengthCommon Rafter Major Span = 1103Common Rafter Minor Span = 745Rise Main Roof = 466Rise Minor Roof = 315Hip Length Major Span = 1.489Hip Length Minor Span = 0.897Hip Rise Major Span = 466Hip Rise Minor Span = 315Creeper Shortening = 497Ridge Major Span
Rafter 90 x 35 @ 450 c to cHip Rafters 140 x 35Ridge 140 x 35
= Length – (Hip Ends x( ½ Span + ½ Rafter)= 3603 – (2 x (1000+ 17)=1569
Lay out of Broken Hip RoofRoof Pitch = 25⁰
Determine Centreline LengthCommon Rafter Major Span = 1103Common Rafter Minor Span = 745Rise Main Roof = 466Rise Minor Roof = 315Hip Length Major Span = 1.489Hip Length Minor Span = 0.897Hip Rise Major Span = 466Hip Rise Minor Span = 315Creeper Shortening = 497Ridge Major Span = 1569
Rafter 90 x 35 @ 450 c to cHip Rafters 140 x 35Ridge 140 x 35
Lay out of Broken Hip RoofRoof Pitch = 25⁰
Determine Centreline LengthCommon Rafter Major Span = 1103Common Rafter Minor Span = 745Rise Main Roof = 466Rise Minor Roof = 315Hip Length Major Span = 1.489Hip Length Minor Span = 0.897Hip Rise Major Span = 466Hip Rise Minor Span = 315Creeper Shortening = 497
Rafter 90 x 35 @ 450 c to cHip Rafters 140 x 35Ridge 140 x 35 As both spans are the
same pitch they are SIMILAR so Creeper Shortening is the same for both spans
Lay out of Broken Hip RoofRoof Pitch = 25⁰
Determine Centreline LengthCommon Rafter Major Span = 1103Common Rafter Minor Span = 745Rise Main Roof = 466Rise Minor Roof = 315Hip Length Major Span = 1.489Hip Length Minor Span = 0.897Hip Rise Major Span = 466Hip Rise Minor Span = 315Creeper Shortening = 497
Rafter 90 x 35 @ 450 c to cHip Rafters 140 x 35Ridge 140 x 35
So the roofing members we have previously looked at are determined the same way
Lay out of Broken Hip RoofRoof Pitch = 25⁰
Crippled Centring Rafter
Rafter 90 x 35 @ 450 c to cHip Rafters 140 x 35Ridge 140 x 35
To develop other Roofing Members we need to determine the plan length first
Lay out of Broken Hip RoofRoof Pitch = 25⁰
Determine Crippled Centring Rafter
Distance Between Ridge Minor Span & Crippled Centring Rafter =
Difference Between the two half spans
Rafter 90 x 35 @ 450 c to cHip Rafters 140 x 35Ridge 140 x 35
To develop other Roofing Members we need to determine the plan length first
1000-675 = 325
Lay out of Broken Hip RoofRoof Pitch = 25⁰
Determine Crippled Centring Rafter
We recall that all hips & valleys bisect corners.
In this building it means that they are at 45⁰.
Rafter 90 x 35 @ 450 c to cHip Rafters 140 x 35Ridge 140 x 35
To develop other Roofing Members we need to determine the plan length first
Lay out of Broken Hip RoofRoof Pitch = 25⁰
Determine Crippled Centring Rafter
We recall that all hips & valleys bisect corners.
In this building it means that they are at 45⁰.
Therefore where the Broken Hip intersects the Ridge Minor Span must be 325mm from the Centreline of the Ridge Major Span
Rafter 90 x 35 @ 450 c to cHip Rafters 140 x 35Ridge 140 x 35
To develop other Roofing Members we need to determine the plan length first
Lay out of Broken Hip RoofRoof Pitch = 25⁰
Determine Crippled Centring Rafter
As the valley is at 45⁰ the intersection with the valley must be a further 325mm
Rafter 90 x 35 @ 450 c to cHip Rafters 140 x 35Ridge 140 x 35
To develop other Roofing Members we need to determine the plan length first
Lay out of Broken Hip RoofRoof Pitch = 25⁰
Determine Crippled Centring Rafter
Plan Centreline Length =
2 x (Half Span Major – Half Span Minor)
2 x (1000 – 675)
Rafter 90 x 35 @ 450 c to cHip Rafters 140 x 35Ridge 140 x 35
To develop other Roofing Members we need to determine the plan length first
Lay out of Broken Hip RoofRoof Pitch = 25⁰
Determine Crippled Centring Rafter
Plan Centreline Length =
2 x (Half Span Major – Half Span Minor)
2 x (1000 – 675)
= 650
Rafter 90 x 35 @ 450 c to cHip Rafters 140 x 35Ridge 140 x 35
To develop other Roofing Members we need to determine the plan length first
Lay out of Broken Hip RoofRoof Pitch = 25⁰
Plan Centreline Length = 650mm
Deduct ½ Ridge Thickness = 17.5 mm
Deduct/Add Long Point Correction
Rafter 90 x 35 @ 450 c to cHip Rafters 140 x 35Ridge 140 x 35
Develop True Length of Crippled Centring Rafter
Lay out of Broken Hip RoofRoof Pitch = 25⁰
Plan Centreline Length = 650mm
Deduct ½ Ridge Thickness = 17.5 mm
Deduct/Add Long Point Correction
•Deduct ½ Hip x 1.414
Rafter 90 x 35 @ 450 c to cHip Rafters 140 x 35Ridge 140 x 35
Develop True Length of Crippled Centring Rafter
Lay out of Broken Hip RoofRoof Pitch = 25⁰
Plan Centreline Length = 650mm
Deduct ½ Ridge Thickness = 17.5 mm
Deduct/Add Long Point Correction
•Deduct ½ Hip x 1.414 =25mm
•Add ½ Rafter Thickness =
Rafter 90 x 35 @ 450 c to cHip Rafters 140 x 35Ridge 140 x 35
Develop True Length of Crippled Centring Rafter
Lay out of Broken Hip RoofRoof Pitch = 25⁰
Plan Centreline Length = 650mm
Deduct ½ Ridge Thickness = 17.5 mm
Deduct/Add Long Point Correction
•Deduct ½ Hip x 1.414 =25mm
•Add ½ Rafter Thickness = 17.5
True Length = 650 – 17.5 – 25 + 17.5 Cos 25
Rafter 90 x 35 @ 450 c to cHip Rafters 140 x 35Ridge 140 x 35
Develop True Length of Crippled Centring Rafter
Lay out of Broken Hip RoofRoof Pitch = 25⁰
Rafter 90 x 35 @ 450 c to cHip Rafters 140 x 35Ridge 140 x 35
Develop True Length of Crippled Centring Rafter
Plan Centreline Length = 650mm
Deduct ½ Ridge Thickness = 17.5 mm
Deduct/Add Long Point Correction
•Deduct ½ Hip x 1.414 =25mm
•Add ½ Rafter Thickness = 17.5
•Long Point Correction = -7.5 mm
True Length = 650 – 17.5 – 7.5 Cos 25
True Length = 625 = 690 mm to Long Pt (red) Cos 25
Lay out of Broken Hip RoofRoof Pitch = 25⁰
Rafter 90 x 35 @ 450 c to cHip Rafters 140 x 35Ridge 140 x 35
Plumb Cut for Crippled Centring Rafter
Crippled Centring Rafter is in the same plane as the Common Rafters
Therefore it must be the same pitch as the Common Rafters, so it must have the SAME PLUMB CUT AT BOTH ENDS
Lay out of Broken Hip RoofRoof Pitch = 25⁰
Rafter 90 x 35 @ 450 c to cHip Rafters 140 x 35Ridge 140 x 35
Edge Bevel for Crippled Centring Rafter
What Triangle forms the Bevel ?
Lay out of Broken Hip RoofRoof Pitch = 25⁰
Rafter 90 x 35 @ 450 c to cHip Rafters 140 x 35Ridge 140 x 35
Edge Bevel for Crippled Centring Rafter
What Triangle forms the Bevel
Simple Bevel Development
1. Plumb Bevel Rafter2. Level Bevel Rafter3. Edge Bevel Creeper4. Edge Bevel Purlin5. Plumb Bevel Hip6. Level Bevel Hip7. Edge Bevel Hip8. Face Bevel Purlin
From Previous
Lay out of Broken Hip RoofRoof Pitch = 25⁰
Rafter 90 x 35 @ 450 c to cHip Rafters 140 x 35Ridge 140 x 35
Edge Bevel for Crippled Centring Rafter
Edge Bevel for Crippled Centring Rafter is the CREEPER EDGE BEVEL
The same is for•Valley Creepers•Crippled Creepers
Lay out of Broken Hip RoofRoof Pitch = 25⁰
Rafter 90 x 35 @ 450 c to cHip Rafters 140 x 35Ridge 140 x 35
Edge Bevel for Crippled Centring Rafter is the CREEPER EDGE BEVEL
The same is for•Valley Creepers•Crippled Creepers
It follows that all the The purlin bevels are The same as the hip end
Lay out of Broken Hip RoofRoof Pitch = 25⁰
Rafter 90 x 35 @ 450 c to cHip Rafters 140 x 35Ridge 140 x 35
Every Valley Creeper must have an opposing creeper
Lay out of Broken Hip RoofRoof Pitch = 25⁰
Rafter 90 x 35 @ 450 c to cHip Rafters 140 x 35Ridge 140 x 35
Every Valley Creeper must have an opposing creeper
Lay out of Broken Hip RoofRoof Pitch = 25⁰
Rafter 90 x 35 @ 450 c to cHip Rafters 140 x 35Ridge 140 x 35
Every Valley Creeper must have an opposing creeper
Lay out of Broken Hip RoofRoof Pitch = 25⁰
Rafter 90 x 35 @ 450 c to cHip Rafters 140 x 35Ridge 140 x 35
Every Valley Creeper must have an opposing creeper
From previous calculations we determined the following
Lay out of Broken Hip RoofRoof Pitch = 25⁰
Rafter 90 x 35 @ 450 c to cHip Rafters 140 x 35Ridge 140 x 35
Every Valley Creeper must have an opposing creeper
Centreline length is the same as distance from the gathering point
Lay out of Broken Hip RoofRoof Pitch = 25⁰
Rafter 90 x 35 @ 450 c to cHip Rafters 140 x 35Ridge 140 x 35
Every Valley Creeper must have an opposing creeper
To determine true length Long Pt
Centreline length 325
Deduct ½ Ridge 17.5
+/- Long Point Correction -7.5
TL = 300/cos 25 =
Lay out of Broken Hip RoofRoof Pitch = 25⁰
Rafter 90 x 35 @ 450 c to cHip Rafters 140 x 35Ridge 140 x 35
Every Valley Creeper must have an opposing creeper
To determine true length Long Pt
Centreline length 325
Deduct ½ Ridge 17.5
+/- Long Point Correction -7.5
TL = 300/cos 25 = 331 (RED)
NOTE - Long Point Correction will be the same if the Valley & Rafter are the same thickness
Lay out of Broken Hip RoofRoof Pitch = 25⁰
Rafter 90 x 35 @ 450 c to cHip Rafters 140 x 35Ridge 140 x 35
Determine Centreline Length Broken Hip
Lay out of Broken Hip RoofRoof Pitch = 25⁰
Rafter 90 x 35 @ 450 c to cHip Rafters 140 x 35Ridge 140 x 35
Determine Centreline Length Broken Hip
Lay out of Broken Hip RoofRoof Pitch = 25⁰
Rafter 90 x 35 @ 450 c to cHip Rafters 140 x 35Ridge 140 x 35
Broken Hip Run325 x 1.414 = 460
Lay out of Broken Hip RoofRoof Pitch = 25⁰
Rise will be the difference between each span
Hip Run = 460
Rise Main Roof = 466Rise Minor Roof = 315
= 151
Lay out of Broken Hip RoofRoof Pitch = 25⁰
Rise will be the difference between each span
Hip Run = 460
Rise Main Roof = 466Rise Minor Roof = 315
= 151
Broken Hip = √(460² + 151²) =
Lay out of Broken Hip RoofRoof Pitch = 25⁰
Rise will be the difference between each span
Hip Run = 460
Rise Main Roof = 466Rise Minor Roof = 315
= 151
Broken Hip = √(460² + 151²) = 484
Pitch = Tan-1 (151/460)= Tan-1 (0.328)= 18.17⁰
Lay out of Broken Hip RoofRoof Pitch = 25⁰
Rafter 90 x 35 @ 450 c to cHip Rafters 140 x 35Ridge 140 x 35
Determine True Length Broken Hip
Lay out of Broken Hip RoofRoof Pitch = 25⁰
Rafter 90 x 35 @ 450 c to cHip Rafters 140 x 35Ridge 140 x 35
Determine True Length Broken Hip
Plan Centreline Length =
Lay out of Broken Hip RoofRoof Pitch = 25⁰
Rafter 90 x 35 @ 450 c to cHip Rafters 140 x 35Ridge 140 x 35
Determine True Length Broken Hip
Plan Centreline Length = 460
Deduct Hip End Reduction = ½ Crown End x 1.414½ Hip Thickness
Lay out of Broken Hip RoofRoof Pitch = 25⁰
Rafter 90 x 35 @ 450 c to cHip Rafters 140 x 35Ridge 140 x 35
Determine True Length Broken Hip
Plan Centreline Length = 460
Deduct Hip End Reduction = -42
Lay out of Broken Hip RoofRoof Pitch = 25⁰
Rafter 90 x 35 @ 450 c to cHip Rafters 140 x 35Ridge 140 x 35
Determine True Length Broken Hip
Plan Centreline Length = 460
Deduct Hip End Reduction = -42
Deduct / Add Long Point Correction =less ½ Ridge x 1.414 = - 25add ½ Hip Thickness = +17.5
= -7.5
Lay out of Broken Hip RoofRoof Pitch = 25⁰
Rafter 90 x 35 @ 450 c to cHip Rafters 140 x 35Ridge 140 x 35
Determine True Length Broken Hip
Plan Centreline Length = 460
Deduct Hip End Reduction = -42
Deduct / Add Long Point Correction =less ½ Ridge x 1.414 = - 25add ½ Hip Thickness = +17.5
= -7.5
True Run = 460 -42 – 7.5 = 411.5
Lay out of Broken Hip RoofRoof Pitch = 25⁰ Hip Pitch 18.17⁰
Rafter 90 x 35 @ 450 c to cHip Rafters 140 x 35Ridge 140 x 35
Determine True Length Broken Hip
Plan Centreline Length = 460
Deduct Hip End Reduction = -42
Deduct / Add Long Point Correction =less ½ Ridge x 1.414 = - 25add ½ Hip Thickness = +17.5
= -7.5
True Run = 460 -42 – 7.5 = 411.5True Length Long Point = 411.5/ Cos 18.17
= 433mm
Lay out of Broken Hip RoofRoof Pitch = 25⁰
Rafter 90 x 35 @ 450 c to cHip Rafters 140 x 35Ridge 140 x 35
Plumb cut is the same as the hipEdge Bevels are the same as the hip
Lay out of Broken Hip RoofRoof Pitch = 25⁰
Rafter 90 x 35 @ 450 c to cHip Rafters 140 x 35Ridge 140 x 35
With the more complex roof. It is important to plan & set out the basic frame of the roof.