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.
Traditional cut rafter and purlin roof.
The overall construction of a traditional cut roof is to ensure that the load of the roof is evenly transmitted to the walls below.
9 complex purlin roofs.
The rafters are the main load bearing elements of the roof.
This diagram illustrates the typical arrangement of a rafter and purlin roof and shows the dimensions referred to in the tables above.
The longitudinal horizontal beam that is sitting on a post or the principal rafter of a truss and used to support common rafters.
From the 1970s onwards most low rise domestic pitched roofs have been formed with trussed rafters.
5 eaves details less common.
It also makes up a web of braces in modern trussed roofs.
Traditional cut roofs contents.
8 simple purlin roofs.
2 lean to roofs simple.
Post roofs are internal support struts in the loft it props up the rafters and purlins in traditional cut and pitched roofs.
A common arrangement is a rafter and purlin system which combines purlins and rafters.
Purlin plates under purlin principal purlins and common purlins.
10 complex new roofs.
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.
These are normally only required to trussed rafter roofs and not for traditional purlin and rafter roof construction.
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.
Traditional or cut roofs usually comprise a series of.
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.
There are three types of purlins in wood construction.
Parts of a traditional queen post roof truss.
3 lean to roofs less common.
Boarded roof is a roof where the rafters are covered in boarding just before the roofing felt and tiles slates are fixed on to the structure.
Building control guidance note purlin and rafter roofs timber sizes and construction details.
4 eaves details simple.
There are two basic methods of pitched roof construction.
7 simple traditional roofs.
In finished space insulation is placed between the rafter boards and drywall or other material is fastened to the face.
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.
Gable walls need to be strapped to the roof at the maximum 2m centres using 30 x 5m galvanised mild steel straps.
