Note that these are normally only required to trussed rafter roofs and not for traditional purlin and rafter roof construction.
Traditional rafter and purlin roof construction.
Traditional or cut roofs usually comprise a series of sloping timbers rafters fixed to a wall plate at their feet and a ridge board or possibly a wall plate at their head.
There are three types of purlins in wood construction.
All the figures are based on roofing tiles or slates laid on.
The overall construction of a traditional cut roof is to ensure that the load of the roof is evenly transmitted to the walls below.
Purlin plates under purlin principal purlins and common purlins.
By supporting the rafters they allow longer spans than the rafters alone.
The rafters are the main load bearing elements of the roof.
They span from the wallplate to the ridge board providing a platform for the underlay battens and tiles.
Exposed rafters are a feature of some traditional roof styles.
The term plate means a major horizontal supporting timber.
A purlin plate in wood construction is also called an arcade plate in european english under purlin and principal purlin.
Building control guidance note purlin and rafter roofs timber sizes and construction details.
Sizes used in traditional roofing construction.
7 simple traditional roofs.
Purlin plates in wooden construction.
A common arrangement is a rafter and purlin system which combines purlins and rafters.
This is the right way to fix truss clips connecting the rafter and wall plate.
8 simple purlin roofs.
In architecture structural engineering or building a purlin or historically purline purloyne purling perling is any longitudinal horizontal structural member in a roof except a type of framing with what is called a crown plate.
Pitched roof construction.
There are two basic methods of pitched roof construction.
10 complex new roofs.
These are normally only required to trussed rafter roofs and not for traditional purlin and rafter roof construction.
Purlin plates are beams which support the mid span of rafters and are supported by posts.
Parts of a traditional queen post roof truss.
A cut roof this is the traditional method of cutting the timber on site and building up the roof using rafters ridge boards joists and purlins etc the exact details being determined by the size of roof size of timbers etc.
The longitudinal horizontal beam that is sitting on a post or the principal rafter of a truss and used to support common rafters.