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Chapter 20. Roof Plan Components. Links for Chapter 20. Roof Plan Types. Roof Shape. Roof Materials. Related Web Sites. 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
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Chapter 20 Roof Plan Components
Links for Chapter 20 Roof Plan Types Roof Shape Roof Materials Related Web Sites
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
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
Roof Shape • Flat Roof • Economical • Built with slight pitch so water can run off • Parapet (false wall) is built around the roof
Roof Shape • Shed Roof • Less drainage problems compared to flat roof • Can be built at any pitch
Roof Shape • Gable Roof • Two shed roofs meet at a ridge • Two or more gables meet to form a hip or valley
Roof Shape • A-Frame Roof • Rafters are used as supporting walls • The structure appears to form the letter “A”
Roof Shape • Gambrel Roof • Traditional shape from colonial period • Upper roof is greater pitch than lower roof • Reduces cost of siding
Roof Shape • Hip Roof • Eliminates roof mass • Structure appears smaller • Two hips form a valley
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
Roof Shape • Mansard Roof • Similar to a gambrel but angled lower roof is on all four sides
Roof Shape • Dormers • Opening in a roof to allow for a window • Used in gable or hip roof
Roof Slope Flat Roof: 2/12 Low Slope: 2/12-4/12 Conventional Slope Roof: 4/12-9/12 Steep Slope: 9/12 and higher
Pitch= Rise/ Clear Span • Slope (pitch)= Rise : Run • Example: 5:12 • Pitch = Rise • ___________ Span = 5/24
Roof Pitch Command: Line<45 & Dimension http://www.pole-barn.info/roof-pitch.html
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
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
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
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
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
Related Web Sites • Asphalt Roofing Manufactures - www.asphaltroofing.com • Cedar Shake & Shingle Bureau - www.cedarbureau.org • Roofing Industry Educational Institute- www.riei.com • Single Ply Roofing Institute- www.spri.com