Modern timber roofs are mostly framed with pairs of common rafters or prefabricated wooden trusses fastened together with truss connector plates.
Timber roof spars.
All the figures are based on roofing tiles or slates laid on timber laths over sarking felt.
3 part of a suspended timber floor construction that provides a level.
2 part of a flat roof structure that receives the ends of the flat roof joists.
The edge of a roof which runs from eaves to ridge at a gable.
Replacement roof tiles may be heavier than those the structure was designed to support timbers may have become rotten other planned structural alterations may necessitate strengthening or perhaps the structure was not strong enough in the first place.
8 2 most commonly used in the construction of floor joists and roof applications but very adaptable and can be used in many other areas this size is great for raised beds all treated and good for outdoor use.
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.
Timber framed and historic buildings may be framed with principal rafters or timber roof trusses.
Cutting and laying roof rafters for the vaulted roof duration.
Pitched roof timber sizes.
Timber roof on a single storey extension duration.
In this diy guide you will learn how to install a roofing joist or rafter that includes how to work out the pitch of a roof cut a ridge or plumb cut at the correct angle work out the correct length of joist you need and the exact location for a birds mouth joint how to correctly cut a birds.
Surveyors span tables for designing roof rafters.
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.
Lifetime coverage on shingles requires the use of gaf lifetime shingles only.
The following tables give details of the allowable spans and spacing for some of the more common timber sizes used in traditional roofing construction.
1 lifetime refers to the length of warranty coverage provided and means as long as the original individual owner s of a single family detached residence or the eligible second owner s owns the property where the qualifying gaf products are installed.
1 part of a pitched roof construction that receives the feet of the spars sp ars and ceiling joist ends.
Birdsmouth joint how to cut a birdsmouth and how to cut and install roofing rafters and joists.
For other owners structures lifetime coverage is not applicable.
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.
