9 complex purlin roofs.
Traditional cut rafter and purlin roof.
Traditional cut roofs contents.
The longitudinal horizontal beam that is sitting on a post or the principal rafter of a truss and used to support common rafters.
It also makes up a web of braces in modern trussed roofs.
Building control guidance note purlin and rafter roofs timber sizes and construction details.
The boards creating the slope of the roof are wider than lumber used to build trusses 2x8s 2x10s and 2x12s are most common in rafters vs.
A traditional cut timber roof incorporating a collar for lateral restraint purlins for rigidity and struts to distribute some of the load to an internal load bearing wall.
There are three types of purlins in wood construction.
A rafter and purlin roof and shows the dimensions referred to.
They span from the wallplate to the ridge board providing a platform for the underlay battens and tiles.
Rafter boards are fastened to the ridge board at the peak and the top plate where they join the wall.
The rafters are the main load bearing elements of the roof.
The roof support system is a ridgepole and either rafters which run perpendicular from the top of the walls to the ridge or purlins which run parallel to the ridge.
7 simple traditional roofs.
Purlin plates under purlin principal purlins and common purlins.
These are normally only required to trussed rafter roofs and not for traditional purlin and rafter roof construction.
2 lean to roofs simple.
This diagram illustrates the typical arrangement of a rafter and purlin roof and shows the dimensions referred to in the tables above.
In finished space insulation is placed between the rafter boards and drywall or other material is fastened to the face.
The overall construction of a traditional cut roof is to ensure that the load of the roof is evenly transmitted to the walls below.
Pitched roof construction.
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.
From the 1970s onwards most low rise domestic pitched roofs have been formed with trussed rafters.
Post roofs are internal support struts in the loft it props up the rafters and purlins in traditional cut and pitched roofs.
10 complex new roofs.
Gable walls need to be strapped to the roof at the maximum 2m centres using 30 x 5m galvanised mild steel straps.
5 eaves details less common.
11 some examples of older traditional roofs.
3 lean to roofs less common.
8 simple purlin roofs.
A common arrangement is a rafter and purlin system which combines purlins and rafters.
Traditional or cut roofs usually comprise a series of.
