Roofing With Asphalt Shingles 1 - Sheathing Preparation

Requirements on sheathing used on roofs shingled with asphalt patterns

The asphalt shingles are very flexible roofing material and they are probably least demanding on framing and sheathing preparation.

The flexibility of asphalt roofing patterns enables their usage on various types and shapes of roof and gives the architects really generous place to play around with the roof design.

Asphalt shingles can be used wherever on roofs with slopes from 15 to 90 degrees (3/12 to vertical wall roof) and the only thing that is required when roofing with asphalt patterns is that the underlayment must be as flat as possible.

Deck/sheathing preparation for asphalt shingles

To provide the flat sheathing it is recommended to use the decking planks of approximately 4 to 9 inches width only.

With wider planks you can experience warping of the wooden sheathing mainly if the sheathing material was not dry enough. Instead of wooden planks you can also use dimensional plywood panels (1/2 inch or thicker) with waterproof treatment (close to zero absorptiveness).

The quality of wooden sheathing depends very much from humidity of used material (planks, plywood), generally it should be as dry as possible (otherwise we risk they will warp during drying). As asphalt roofing patterns are very flexible, they will copy the surface of the deck and if the decking is warped the roof surface will look awfully.