Roof Timber Sizes And Spans

Find the column for your dead load and spacing and the row for your timber size to find the permissible clear span in metres.

Roof timber sizes and spans.

All the figures are based on roofing tiles or slates laid on timber laths over sarking felt. In any other situation you should refer to trada document span tables for solid timber members in floors. Rafter spans can be extended slightly beyond what the rafter tables suggest when there is a cantelever extending beyond the supporting wall. For heavy roofs or in areas with substantial snowfall or winds call your local building department for code requirements.

Maximum rafter spans for a patio roof in areas with mild climates patio roofs are generally designed for loads of 30 psf pounds per square foot. This span table is to the format and methodology given in bs 5268 7 2. These spans were calculated using our flat roof joist calculation. Pitched roof timber sizes.

Ceiling joist span use this table to determine the maximum lengths of ceiling joists based on species of lumber joist spacing and joist size. Surveyors span tables for designing roof rafters. All figures are based on normal loading conditions found in domestic construction. For pitched roofs flat roofs and ceiling joists.

Surveyors and structural engineers utilise data from tables below to help calculate the correct size strength and centres of roof timbers for the required spans and loadings.