Care needs to be taken in understanding the sizes stated some are stated in sawn sizes and others in finished ie planed.
Roof timber sizes uk.
Compliment our range we stock batten firrings arris rail and a range of treated timbers in various sizes and can quickly source and supply any of your timber requirements.
Most independent timber merchants in the uk will offer a range of both sawn and planed timber.
Pitched roof timber sizes.
High quality timber supplies for virtually any construction project.
The following tables give details of the allowable spans and spacing for some of the more common timber sizes used in traditional roofing construction.
Imposed loads of 1 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.
Should refer to trada document span tables for solid timber members in floors ceilings and roofs excluding trussed rafter roofs for dwellings or ask your lbc surveyor for advice.
Surveyors span tables for designing roof rafters.
1 2 timber strength class and joist size automatically calculate sizes suitable for supporting the loads below c16 cost effective for most applications c24 stronger more demanding c14 c18 c22 c27 c30 c35 c40.
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.
Suitable for uk building regulation approval.
For pitched roofs flat roofs and ceiling joists.
Structural calculations for timber joists timber beams glulam beams flitch beams using the latest design codes.
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.
Including osb plywood and chipboard for flooring roofing and other structural applications.
C16 timber is kiln dried timber certified to comply with the criteria of strength grade c16.
C16 timber is commonly used in floor and roof joists for internal building work.
Imposed loads roof snow load and short term point load altitude not exceeding 100m.
It s often chosen as the standard timber for roof extensions or joist refurbishment as it s the most cost effective internal structural timber.
All the figures are based on roofing tiles or slates laid on timber laths over sarking felt.