1. Chapter 22
Roof Plan Components

2. Introduction Roof design is considered before the plan
Designer considers shape, type, and aesthetics as floor plan and elevations are drawn
Drafter should understand types, pitches, shapes, and materials

3. Types of Roof Plans Roof plan Roof framing plan
Used to show roof shape
Roof framing plan
Usually required for complicated roof shapes
Shows size and direction of construction members required to frame the roof

7. Common Roof Terms Common terms: Ridge Overhangs Eaves and rakes
Roof pitch (e.g., slight, gradual, moderate, and steep slopes)
Sun angle
Overhang size
Eaves and rakes
Boxed and soffited eaves
Cornice
Fascias and barge rafters

10. Roof Shapes Common roof shapes include: Flat Shed Gable A-frame
Gambrel
Hip and Dutch hip
Mansard

15. Roofing Materials Material depends on: Pitch Exterior style Cost
Weather

16. Roofing Materials (cont’d.)
Types of materials:
Built-up roofing
Felt and asphalt used on flat or low-sloped roofs
Shingles
Asphalt, fiberglass, and wood
Wood is also used for shakes (thicker shingles with irregular texture)
Masonite and metal

18. Roofing Materials (cont’d.)
Types of materials (cont’d):
Clay and cement tiles
Used for high end homes or risk of fire is extreme
Metal panels
Provide savings
Speed and ease of installation
Metal is also used for flashing at all levels

20. Roof Ventilation and Access
Attic is the space formed between ceiling joists and rafters
Typically provided with vents covered with 1/16" minimum and ¼" maximum screen mesh
Vents must have an area equal to 1/150 of attic
Area can be reduced to 1/300
50% (not more than 80%) of ventilating area is provided by ventilators in the upper portion of space

21. Roof Ventilation and Access (cont’d.)
Unvented attics
Area is completely contained in building thermal envelope
Additional requirements
Refer to the text

22. Roof Ventilation and Access (cont’d.)
Attic access
Drafter must specify how to get in if area is 30 sq ft or more and height is 30" or more
Actual opening is usually shown on floor plan
Location must be considered when roof plan is being drawn
Minimum size is 22" × 30" with 30" minimum headroom