Post on 18-Jan-2016
transcript
Roof Designs & Construction
Calculating a Roof Pitch
Architecture I
What is the Roof Pitch?
The roof's Pitch is what is called "slope" in geometry
Pitch = Rise/Run Run = ½ Span
Roof Pitch to Degree Equivalents
This drawing demonstrates how many degrees rise for each pitch of a typical roof. Look at the column labeled pitch, then look under degrees to get the corresponding amount of degrees.
Example;
8/12 pitch = 33.75 degrees.
Common
Roof Pitches
Various Roof Pitches
The roof pitch is defined in ranges which can reasonably be determine from field observation without precise measurement.
o Very Low or Flat Roofs are < 1 in 12 pitch
o Low Pitched Roofs are < 4 in 12 pitch
o Medium Pitched Roofs are < 9 in 12 pitch
o Steep Roofs are < 12 in 12 pitch
o Very Steep Roofs are > 12 in 12 pitch
Roof Plan
Sketch the Front Elevation
Roof Pitch & Roof Plan Problem
Calculate the roof pitch and sketch the roof plan for the following house:
2 STORY HOUSE 2 CAR GARAGE
48’-0”
32’
-0”
24’-0”
2
2’-0
”
Roof Framing Systems
Architecture IFairport High School
Roof Members
Conventional Framed Roof
Wood Trussed Roof
Carpenter Truss Components
Trussed Rafter Components
Trussed Gambrel Components
Flat Roof Truss Components
Truss Types
Cornice Framing Details
Drawing a Cornice Section
Roof Plan
Detailed Roof Framing Plan
Roof Framing Plan Detail
Rafter SpansMaximum Span Size
Rafter Spacing Rafter Group 1 Group 2 Group 3 Group 4
12” 10’-0” 9’-0” 7’-0” 4’-0”
16” 9’-0” 7’-6” 6’-0” 3’-6”
24” 7’-6” 6’-6” 5’-0” 3’-0”
2 x 4
32" 6’-6” 5’-6” 4’-0” 2’-6”
12” 17’-6” 15’-0” 12’-6” 9’-0”
16” 15’-6” 13’-0” 11’-0” 8’-0”
24” 12’-6” 11’-0” 9’-0” 6’-6”
2 x 6
32" 11’-0” 9’6” 8’-0” 5’-6”
12” 23’-0” 20’-0” 17’-0” 13’-0”
16” 20’-0” 18’-0” 15’-0” 11’-6”
24” 17’-0” 15’-0” 12’-6” 9’-6”
2 x 8
32" 14’-6” 13’-0” 11’-0” 8’-6”
12” 28’-6” 26’-6” 22’-0” 17’-6”
16” 25’-6” 23’-6” 19’6” 15’-6”
24” 21’-0” 19’-6” 16’-0” 12’-6”
2 x 10
32" 18’-6” 17’-0” 14’-0” 11’-0”
Wood Ceiling Joist Spans
Maximum Span Size Ceiling J oists
Spacing Ceiling J oists
Wood Group 1
Wood Group 2
Wood Group 3
Wood Group 4
12” 11’-6” 11’-0” 9’-6” 5’-6” 2 x 4 16” 10’-6” 10’-0” 8’-6” 5’-0”
12” 18’-0” 16’-6” 15’-6” 12’-6” 2 x 6 16” 16’-0” 15’-0” 14’-6” 11’-0”
12” 24’-0” 22’-6” 21’-0” 19’-0” 2 x 8 16” 21’-6” 20’-6” 19’-0” 16’-6”