Roofing Osb Upside Down

Roof trusses must be dry when sheathing a roof with osb to prevent mold growth in the roof and coverage gaps as the trusses dry and shrink.

Roofing osb upside down.

Install osb textured side up. Osb roof panels should always be installed with the grade stamp facing into the attic and the screened surface with the nail guide lines facing up. Installing the panels this way allows for material verification and inspection from below when carpet or tile may be covering the top side and ensures that the tongue and groove joints will properly align and avoid causing an uneven lip at the panel edges. Curved or uneven roof trusses will cause osb roof sheathing to warp or buckle under roof coverings.

The screened surface also provides a little more. Avoid putting osb on wet roof trusses. The osb roof panels should be installed with the grade stamp facing into the attic and the screened surface with the nail guide lines facing up. Oriented strand board isn t plywood nor is it a type of particleboard fiberboard or wafer board and although it is a newcomer to a plywood dominated market its use for exterior sheathing is.

Structurally it doesn t make a difference but if the grade stamp faces up it will be covered by the roofing material and the building inspector will not be able to confirm the right osb panel has. When the grade stamp is covered by roofing the building inspector will not be able to confirm that the correct osb roofing panel was used. Avoid installing osb with the textured side down. It s also funny watching carps installing one of the new roof products that replaces felt.

I m halfway though sheeting the roof of my shipping container shop and already need to redo some of it. The textured surface helps flashing and waterproof underlay stay in place effectively. It s like putting tyvek with the writting upside down it just doesn t seem right to many.