Building span = 28’-0” Roof = 5:12 (1.083) Exterior wall height = 8’-0” Foundation wall height = 4’-0” Overhang = 18” (both Soil bearing strength = 2000 lbs per sqft. Rafter length: Span + Overhang = “Run” 2 Run x Mult. Fact. = Rafter Lgth 28’ + 3’ = 15.5’ ( or 15’-6”) 2 15.5 x 1.083 = 16.79’ (16’-9 1/2”) 30.0 Roof: Live load = psf Dead load (asphalt shingles) = 2.0 Dead load (1/2” plywood) = psf Dead load (2x6 rafters @ 16” o.c.) 1.6 Load = psf 2.5 psf 16.79’ x 36.1 36.1 Rafter length = psf 606.1 lbs 20.0 Ceiling: Live load = psf Dead load (1/2” sheet rock) = 2.2 Dead load (1/2” plywood) = psf Dead load (2x6 joists @ 16” o.c.) 1.6 Total Load = psf 14.0’ x 28.8 = 5.0 Half Span psf 28.8 psf 403.2 lbs
Building span = 28’-0” Roof = 5:12 (1.083) Exterior wall height = 8’-0” Foundation wall height = 4’-0” Overhang = 18” (both Soil bearing strength = 2000 lbs per sqft. Rafter length: Span + Overhang = “Run” 2 Run x Mult. Fact. = Rafter Lgth 28’ + 3’ = 15.5’ ( or 15’-6”) 2 15.5 x 1.083 = 16.79’ (16’-9 1/2”) Roof: Live load = Dead load (asphalt shingles) = Dead load (1/2” plywood) = Dead load (2x6 rafters @ 16” o.c.) Load = Rafter length 16.79’ x 36.1 = 30.0 psf 2.0 psf 1.6 psf 2.5 psf 36.1 psf 606.1 lbs Ceiling: Live load = Dead load (1/2” sheet rock) = Dead load (1/2” plywood) = Dead load (2x6 joists @ 16” o.c.) Total Load = Half Span 14.0’ x 28.8 = 20.0 psf 2.2 psf 1.6 psf 5.0 psf 28.8 psf 403.2 lbs