Construction Purlin Flat Roof

A purlin plate in wood construction is also called an arcade plate in european english under purlin and principal purlin.

Construction purlin flat roof. 8 x section modulus of a 4 2 of 1 3125 x fb fiberstress in bending x 1 15 duration of load x 1 15 cr repetitive member factor as the purlins are spaced 24 o c. Purlin plates are beams which support the mid span of rafters and are supported by posts. Roof live load roof dead load x spacing x span of purlin 2. Too high a snow load means the purlins fail regardless of how close together you put them because a 2 4 or 2 6 flat can only span a certain distance between trusses as snow loads increase.

Purlins are an important component in a pre engineered steel structural kit. These structural supports run perpendicular across the rafter beams. They give added support to the roof and also provide a nailing surface for the end panels and drip edge. Metal roof purlins are installed horizontally under metal roofs.

Purlins are 2 by 4 feet and are installed much like metal roofing. The purpose of purlins. Or less x 1 1 cfu the flat use factor for applying the load to the wide face of a member. The term plate means a major horizontal supporting timber.

Also known as sheeting rails purlins create the roofing members of the secondary framing of a steel building. The higher the snow load the closer the purlin spacing required. Purlin plates in wooden construction. By supporting the rafters they allow longer spans than the rafters alone.