Reference tables

Look-up charts built from geometry and stable constants — pitch multipliers, shingle bundles, gutter capacity, insulation R-values and siding exposure.

Roof pitch multiplier & angle chartThe pitch multiplier, angle and percent grade for every common roof pitch from 1/12 to 24/12, with the derivation.Shingle bundles by roof size & wasteBundles of shingles needed for common roof sizes at 10% and 15% waste, from 3 bundles per square.K-style gutter & downspout capacity chartIndustry/SMACNA-derived drainage-area capacities for 5-inch and 6-inch K-style gutters and 2×3 / 3×4 downspouts at 1 in/hr.R-per-inch & depth for R-38/R-49/R-60R-value per inch of common insulation materials and the depth each needs to reach R-38, R-49 and R-60.Vinyl siding panel coverage by exposureSquare feet covered per panel by exposure and panel length, from coverage = exposure/12 × length.