Size Of Purlins For Metal Roof

Purlins are non pressure treated 1 x 4 x 12 lumber that is installed on to the roof in a specific layout pattern and screw pattern.

Size of purlins for metal roof.

7 25 12 in. Net variation for combned dimension. Roof steel dead load 63 psf steel american building components catalogue. Purlins are 2 by 4 feet and are installed much like metal roofing.

3 1 43 lbs ft. Ft 15 23 75 12 in. Available in cee or zee shape red oxide primed or galvanized 16 14 or 12 gauge sizes from 4 up to 12 flange widths of 1 1 2 up to 4 cut to your specified lengths hole punching available load tables available for all material. You don t have a nailing surface on the end of a 1x4.

Twist is measured with the zee laying on a flat surface under its own weight. Roof lumber dead load 62 4 pcf 43 lbs ft. The purpose of the purlins is to provide a solid foundation for the metal roofing panels and trim to be screwed to. Purlin spacing 23 75 in.

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. The typical spacing standards for residential and commercial buildings are about 1 to 2 foot. Cee purlin lengths are cut to length from 6 45 in 1 8 increments though 20 and 25 are the most commonly chosen lengths. For the lighter material such as lightweight aluminum the common spacing length is 4 inches of clear gap.

Step 1 run a tape measure from end to end along the rafters of the roof to determine how many purlins will be needed for installation. They give added support to the roof and also provide a nailing surface for the end panels and drip edge. If you want to know how to support roof purlins they are usually supported by 2 4 or 2 6 struts or posts. They are installed on top of the roof rafters with a felt underlayment or vapor barrier installed on top.

For 2x4s purlins the posts are spaced in 4 feet distance. Purlins are 2 by 4 feet and are installed much like metal roofing. For heavier material such as gage steel the metal roof purlins spacing length could go up to 4 feet. They give added support to the roof and also provide a nailing surface for the end panels and drip edge.

Metal mart offers a complete line of engineered purlin material. Ft psf in purlin weight based on 43 g nds total purlin dead load 1 638 psf. 15 3 12 in. If so you should use dimension lumber like 2x4.