Osb Under Metal Roof

Cross purlin designs with 16 oc are sometimes called for.

Osb under metal roof.

Traditionally metal roofs have used standard 30 pound felt paper underlayment. 1 some metal roofs will be more likely than others to telegraph any unevenness of the surface beneath them. Metal should be installed using a cold roof design so the typical metal assembly would be. Metal roofing roofing answers roofing installation roofing materials oriented strand board commonly referred to as osb is a type of engineered lumber similar to particle board formed by adding adhesives and then compressing layers of wood strands.

Screws will do better than nails. The only reason to put osb on a roof would be in the case of a very narrow very long very tall building with high wind loads ones which would exceed the wind shear carrying capacity of the steel. Osb is widely used as roof decking material. The best underlayment for metal roofs.

1 metal 2 air space of 3 4 or greater using 1x4 or 2x4 purlins 3 wrb and 4 5 8 to 3 4 of ply or osb. Using nominal lumber 1x horizontal underneath and 2x vertical. This case is most certainly the exception to the general rule and happens in far less than 5 of all post frame buildings. Then the top of all your purlins once osb under metal roof panels is placed will be in the same plane and the roof steel will lay flat.

Underlayment must also act as a secondary weather barrier in case the roof fails. You can test fastener pull out resistance. Allen a couple of things to consider. April 3 2017 filed under.