Timber Roof Purlin Sizes

All about purlin span for metal roof.

Timber roof purlin sizes.

But for our calculations we are using 900mm. You don t have a nailing surface on the end of a 1x4. J l neal subject. 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.

They both can be combined well to make sure that the space below the roof. It is suitable to use for roof sheeting from fiber cement. 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. Building control guidance note purlin.

Purlins are spaced based on designs or type of roofing sheets. 2 by 4 i e 50mm by 100mm. If so you should use dimension lumber like 2x4. 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.

Maximum clear span of rafters in metres for roof pitches of between 15 and 45 degrees. 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 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. Wood timber are sawn into various sizes amongst are.

Purlin and rafter roofs timber sizes and construction details author. Roof pitch between 15 and 22 5 degrees with rafter spacing strength class c16. 2 by 2 i e 50mm by 50mm. Roof pitch between 15 and 22 5 degrees with rafter spacing.

Purlins near roof edges or changes of roof slope are subject to higher wind forces than interior purlins. Roof pitch between 15 and 22 5 degrees with rafter spacing strength. Surveyors span tables for designing roof rafters. 2 by 3 i e 50mm by 75mm.

Usually 400 450 or 600mm but any value can be used up to 610mm max. For pitched roofs flat roofs and ceiling joists.