Roof Joist Sizes

Dead load per square metre in kn m supported by joists.

Roof joist sizes.

K series joists range in depth from 10 to 30 and can span up to 60. This ceiling joist span table is based on the 2012 irc for uninhabitable attics with limited storage. It covers 2 common lumber species and sizes at 20 pounds per square foot load. These welded steel products are used to support a building s roof and floors.

About o donnell metal deck. Permissible clear span metres. 2 x 12 s are not listed because you can span pretty much whatever you want. Centre to centre spacing of joists in mm joist size width depth mm 400 450 600 400 450 600 400 450 600.

A 2 by 4 inch joist for instance hangs into the room by 4 inches which may leave the ceiling high while a 2 by 12 inch joist in the same position hangs 12 inches into the room which decreases the ceiling height by 8 inches. The range of joist sizes used in homes varies though between 2 by 4 inches and 2 by 12 inches. These joists easily handle spans that wood systems cannot handle while their lightweight construction makes them much less costly than steel beams. Not more than 0 5 more than 0 5 but not more than 0 75 more than 0 75 but not more than 1.