Flat Roof Joist Sizes

Dead load weight of structure and fixed loads 15 lbs ft 2.

Flat roof joist sizes.

The range of joist sizes used in homes varies though between 2 by 4 inches and 2 by 12 inches. Douglas fir maximum horizontal roof rafter span for lumber grade selected structural and no. These welded steel products are used to support a building s roof and floors. K series joists range in depth from 10 to 30 and can span up to 60.

Standard size of joists though there is no standard joist size for the ceilings in all buildings most average homes use ceiling joists in a board size of 2 by 6 inches. Rafter and joist span faq. Size of joists mm clear span c16 joist m clear span c24 joist m 47 x 95 47 x 120 47 x 145 47 x 170 47 x 195 47 x 220 1 77 2 40 2 89 3 38 3 87 4 36 2 04 2 75 3 47 4 20 4 93 5 66 floor joists flat roof joists assumptions at 400mm centers supporting permanent load excluding self weight of joists up to 50kg m2. Size of roof joist 400mm 450mm 600mm 47 x 97 1 84 1 81 1 74 47 x 120 2 43 2 39 2 27 47 x 145 3 08 3 02 2 87 47 x 170 3 75 3 67 3 42 47 x 195 4 41 4 31 3 92 47 x 220 5 04 4 85 4 41 75 x 170 4 50.

2 are indicated below. 1 ft 0 3048 m. The lengths and sizes of joists vary depending on the species and quality of the lumber used. 1 psf lb f ft 2 47 88 n m 2.

Live load is weight of furniture wind snow and more. As you may imagine there is a fair amount of weight involved here in terms of boards felt etc. This is the distance between joist centres. So any timber joists that are used need to be strong enough to support this weight.

About o donnell metal deck. Old asbestos roofs are often replaced with flat roofs. These joists easily handle spans that wood systems cannot handle while their lightweight construction makes them much less costly than steel beams.