Roof Purlin Wood Purlin Size And Spacing

The typical spacing standards for residential and commercial buildings are about 1 to 2 foot.

Roof purlin wood purlin size and spacing.

15 3 12 in. The standard of purlin length will vary anywhere between 100 to 300 mm while the thickness will vary anywhere between 1 to 3 mm. However engineering determines the optimal spacing between the purlins. For 2x4s purlins the posts are spaced in 4 feet distance.

Usually 400 450 or 600mm but any value can be used up to 610mm max. 3 009 19 1 0019 1 5 12 in. Spacing for purlins on a standard load most designs call for purlin placement at five foot intervals. For the lighter material such as lightweight aluminum the common spacing length is 4 inches of clear gap.

7 25 12 in. Purlin spacing 23 75 in. Twist is measured with the zee laying on a flat surface under its own weight. Ft psf in purlin weight based on 43 g nds total purlin dead load 1 638 psf.

The heavier the expected load is the shorter the distance between the purlins. Roof steel dead load 63 psf steel american building components catalogue. This is the distance between rafter centres. For heavier material such as gage steel the metal roof purlins spacing length could go up to 4 feet.

Net variation for combned dimension. Roof lumber dead load 62 4 pcf 43 lbs ft.