Roof Purlin Wood Purlin Size And Spacing

Roof lumber dead load 62 4 pcf 43 lbs ft.

Roof purlin wood purlin size and spacing.

Ft psf in purlin weight based on 43 g nds total purlin dead load 1 638 psf. Usually 400 450 or 600mm but any value can be used up to 610mm max. 15 3 12 in. Roof steel dead load 63 psf steel american building components catalogue.

Purlin spacing 23 75 in. However engineering determines the optimal spacing between the purlins. Twist is measured with the zee laying on a flat surface under its own weight. For 2x4s purlins the posts are spaced in 4 feet distance.

This is the distance between rafter centres. If you want to know how to support roof purlins they are usually supported by 2 4 or 2 6 struts or posts. For heavier material such as gage steel the metal roof purlins spacing length could go up to 4 feet. The typical spacing standards for residential and commercial buildings are about 1 to 2 foot.

For the lighter material such as lightweight aluminum the common spacing length is 4 inches of clear gap. Spacing for purlins on a standard load most designs call for purlin placement at five foot intervals. 7 25 12 in. Net variation for combned dimension.

3 009 19 1 0019 1 5 12 in. Ft 15 23 75 12 in.