Timber Roof Joist Span Tables Uk

Posi joists mitek manufactures the steel webs used in posi joists.

Timber roof joist span tables uk.

Solid timber strutting to be at least 38mm thick and be a minimum of three quarters of the joist depth. Surveyors span tables for designing roof rafters. Joist spans over 4 5m provide 2 rows of strutting at third span positions. Floor joist span tables for surveyors floor construction.

Span tables span tables can be used to determine the size of a timber member of a particular strength class required for a given span. Usually 400 450 or 600mm but any value can be used up to 610mm max usually 400 450 or 600mm but any value can be used up to 610mm max 1 2 timber strength class and joist size. Span tables for flat roof joists to bs 5268 7 2 imposed loads of 0 75 kn m for maintenance and snow load are applicable where there is no permanent access no fixed ladder or staircase and most areas where the altitude does not exceed 100 metres refer to bs 6399 3. The weight of the timber floor itself consists of the timber joists the plasterboard ceiling underneath it except for suspended timber ground floors the floorboards and the nails or screws used to fix both of the aforementioned coverings.

Where the tables do not apply or where there are concentrated loads floor joists should be designed by an engineer in accordance with technical requirement r5. Joist ik mitek d4 adhesive. Proprietary strutting is to be used in accordance with manufacturers recommendations. Timber to be covered these span tables do not apply to timber which is fully exposed to the elements.

Learn more about the many benefits and find a licensed fabricator. This is the distance between joist centres. Joists are to have minimum end bearing of 40mm. 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.

For pitched roofs flat roofs and ceiling joists. These span tables apply only to flat roof and roof with a slope of up to 10 degrees. Span tables for solid timber joists. These span tables are based on the imposed loads given in bs 5268 7 1 and bs 6399 1 with an imposed uniformly distributed load of 0 25kn m acting together with a concentrated point load of 0 9 kn.

They also tell you what the maximum spacing should be between each section or timber member size of joists mm clear span c16 joist m clear span c24 joist m 47 x 95 47 x 120 47 x 145 47 x 170 47 x 195 47 x 220 1 77 2 40. Posi rafters posi rafters combine the lightness of timber and strength of posi strut steel webs to provide a quality roof system that can span further than alternative timber products. Solid timber joist sizes are provided in the bs 8103 3 span tables.