How Far Apart Are Bar Joist Roofs

The stuff you see when you look up at the roof in a big box store.

How far apart are bar joist roofs.

I measured up the joist using my handy micrometer. Came home opened up my 75 year joist manual and found the chord angles listed in the size chart at the beginning an exact match. Maximum rafter spans for a patio roof. With some structures floor joists are required to be 12 or 24 inches apart on center.

The same concept holds true for roof trusses. In areas with mild climates patio roofs are generally designed for loads of 30 psf pounds per square foot. If the roof is not completely square you can decrease the space between joists but never increase the space. To determine how far apart to set rafters measure the width of the metal panel and then the width of the first hill and valley of the panel.

Asked the client when the building was built. I investigated an existing bar joist roof for a client just the other day. Double the hill and valley width since this is the amount that the panel will overlap the one next to it on each side. Went to the table for the corresponding.

Open web steel bar joists can be spaced up to eight feet apart depending on the size of the steel used and the roof load. Typically pole barn style buildings in my area have bays distance between trusses of 5 feet to 12 depending on pitch insulation and height. If that seems like a lot in st louis in the mid 80 s we once got 24 of snow overnight. You probably should allow for 30 40 lb sq ft snow load the local codes will tell you exactly what.

Proper distance a roof joist is always spaced no more than 16 inches apart from another roof joist. For heavy roofs or in. So the space between rafters can be greater without reducing the maximum span. Bar joists meaning roof trusses with z welded between two angles top and bottom.

Given that 2x8s are actually 1 inches wide it works out to be 14 inches between each joist. Common spacing for trusses on this type of building is often between 2 and 4 feet but trusses built with advanced designs may allow spacing as great as 8 or 12 feet. In other words you would space a roof joist 15 inches apart from another roof joist but never 17 inches apart. This wide spacing creates several dangers to a firefighter cutting an.