1. Chapter 20
Roof Plan Components

2. Links for Chapter 20 Roof Plan Types Roof Shape Roof Materials
Related Web Sites

3. Roof Plan Types
Roof plan is used to show the shape of the roof including roofing material, vent, and underlayment
Size and direction of construction members are drawn
Required for only complex roof designs

4. Roof Pitch
Slope or roof pitch is the description of the angle of the roof as horizontal run and vertical rise
Pitch is represented with a fraction which converts to an angle

5. Roof Shape Flat Roof Economical
Built with slight pitch so water can run off
Parapet (false wall) is built around the roof

6. Roof Shape Shed Roof Less drainage problems compared to flat roof
Can be built at any pitch

7. Roof Shape Gable Roof Two shed roofs meet at a ridge
Two or more gables meet to form a hip or valley

8. Roof Shape A-Frame Roof Rafters are used as supporting walls
The structure appears to form the letter “A”

9. Roof Shape Gambrel Roof Traditional shape from colonial period
Upper roof is greater pitch than lower roof
Reduces cost of siding

10. Roof Shape Hip Roof Eliminates roof mass Structure appears smaller
Two hips form a valley

11. Roof Shape Dutch Hip Roof Combination of hip and gable roof
Center is similar to a gable roof
Ends are similar to a hip roof

12. Roof Shape Mansard Roof
Similar to a gambrel but angled lower roof is on all four sides

13. Roof Shape Dormers Opening in a roof to allow for a window
Used in gable or hip roof

14. Roofing Materials
Roof materials depend on the pitch, style, structure cost, and weather
Squares are used to order roofing materials
A square covers 100 sq. ft. of surface
Roofing materials also effect the framing members and foundation

15. Built-up Roofing Used with pitch below 3/12
Felt and asphalt is commonly use for flat or low-sloped roof
Hot asphalt is spread between the layers of roofing material

16. Shingles Minimum pitch is 4/12 with 15-lb felt underlayment
Made of wood, asphalt, or fiberglass
Most shingles are three-tab with a self-sealing adhesive on the back
Wood shakes are thicker than shingles and more irregular in shape

17. Clay and Cement Tiles
Used on expensive homes where the threat of fire is extreme
Available in both curved and flat designs
Pitch is usually 2½/12 or greater
Roof will be much heavier with tiles

18. Metal Panels Easy to install and therefore less expensive
Panels are made of 22- or 24-gage metal
Provide good water and fire protection
Available in widths of 18” or 24”
Variety of metals are available including copper, stainless steel, aluminum and zinc

19. Related Web Sites
Asphalt Roofing Manufactures -
Cedar Shake & Shingle Bureau -
Roofing Industry Educational Institute-
Single Ply Roofing Institute-