Required Thickness Cover Board Roof

Densdeck roof board.

Required thickness cover board roof.

However the use of a cover board far exceeds that of a substrate it also serves as a critical component that helps to extend the life of a roof. A cover board is a thin substrate to which a roof membrane is adhered. The thickness is often chosen based on the need for the board to provide integrity over the roof deck such as at flute spans on steel roof decks. First it reduces the shank length of the fastener by as much as one half of the total insulation thickness.

Compared to inch hd polyiso board at 0 34 lbs sq ft. The fastener is only required to penetrate through the bottom layer of the insulation. Some cover boards are very heavy making them difficult to handle slowing down work and potentially adding labor costs. Structodek hd with primed red coating is a high density wood fiber roof cover board with a proprietary red primer on two sides that provides an optimal bonding surface for single ply adhesives hot asphalt and unlike other wood fiber boards firestone mb cold adhesive.

Meets the requirements of astm c 1325. The most common rafter spacing is 24 inches and 5 8 inch plywood is recommended for that. Superior dimensional stability over competitive gypsum fiber boards is due to their low coefficient of thermal and hygrometric expansion. Composed of a lightweight cementicious core to provide exceptional impact resistance.

The type of substrate board should be chosen based on the roof deck type interior building use installation time of year and the cover material to be placed upon it. Exceptionally high compressive strength improves overall roof system performance cement board is able to withstand prolonged exposure to moisture and is ideal for systems where wind uplift and puncture resistance are a concern. The building is more susceptible to hail fi re and wind damage. It can be used with single ply roof systems as well as bur and mod bit.

For example inch gypsum board weighs around 2 lbs sq ft. For rafters spaced 20 or more inches apart 1 2 or 5 8 inch plywood is recommended. A cover board is typically a gypsum board that is installed directly under the membrane. The 1 architecturally specified fiberglass mat gypsum roof cover board for nearly 30 years 1.

Also some boards notably perlite and fiber boards don t cut cleanly and often create nuisance dust. An exceptional fire barrier thermal barrier and re cover board used in various commercial roofing systems. Without a cover board the roof is missing added durability.