Timber Roof Purlin Sizes

Purlin and rafter roofs timber sizes and construction details author.

Timber roof purlin sizes.

But for our calculations we are using 900mm. 2 by 3 i e 50mm by 75mm. Roof pitch between 15 and 22 5 degrees with rafter spacing. Roof pitch between 15 and 22 5 degrees with rafter spacing strength class c16.

J l neal subject. 2 by 4 i e 50mm by 100mm. Purlins near roof edges or changes of roof slope are subject to higher wind forces than interior purlins. All the figures are based on roofing tiles or slates laid on.

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. Usually 400 450 or 600mm but any value can be used up to 610mm max. Purlins are spaced based on designs or type of roofing sheets. 2 by 2 i e 50mm by 50mm.

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. 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. Maximum clear span of rafters in metres for roof pitches of between 15 and 45 degrees.

They both can be combined well to make sure that the space below the roof. Wood timber are sawn into various sizes amongst are. Roof pitch between 15 and 22 5 degrees with rafter spacing strength. Building control guidance note purlin.

It is suitable to use for roof sheeting from fiber cement. For pitched roofs flat roofs and ceiling joists. The following tables give details of the allowable spans and spacing for some of the more common timber sizes used in traditional roofing construction. If so you should use dimension lumber like 2x4.

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. All about purlin span for metal roof.