Timber Roof Purlin Sizes

Roof pitch between 15 and 22 5 degrees with rafter spacing strength class c16.

Timber roof purlin sizes.

Purlin and rafter roofs timber sizes and construction details author. Wood timber are sawn into various sizes amongst are. The following tables give details of the allowable spans and spacing for some of the more common timber sizes used in traditional roofing construction. Surveyors span tables for designing roof rafters.

Now if you are strapping the rafters 1x4 pt is usually used set at 2 intervals or closer and you double the first one at the edge of the metal. Purlins near roof edges or changes of roof slope are subject to higher wind forces than interior purlins. Purlins are the wood of 2 by 2 or 50mm by 50mm we nail the roofing sheets on. This is the distance between rafter centres.

It is suitable to use for roof sheeting from fiber cement. Roof pitch between 15 and 22 5 degrees with rafter spacing strength. If so you should use dimension lumber like 2x4. All the figures are based on roofing tiles or slates laid on.

2 by 2 i e 50mm by 50mm. Maximum clear span of rafters in metres for roof pitches of between 15 and 45 degrees. 2 by 4 i e 50mm by 100mm. But for our calculations we are using 900mm.

Building control guidance note purlin. Usually 400 450 or 600mm but any value can be used up to 610mm max. Roof pitch between 15 and 22 5 degrees with rafter spacing. You don t have a nailing surface on the end of a 1x4.

As per as1684 and as4055 spanman adopts a nett pressure coefficient applied along the full length of the purlin of cpn 2 0 for non cyclonic zones n1 to n6 and cpn 2 5 for cyclonic zones c1 to c4. Purlins are spaced based on designs or type of roofing sheets. 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.

Vc row vc column vc column text timber purlins supplier we have a large range of tanalised purlins in stock for timber contruction of farm and agricultural. All about purlin span for metal roof.