Flat Roof Felt Thickness

Cold roofs and warm roofs.

Flat roof felt thickness. Roof sheathing comes in grid marked 4 by 8 foot sheets and should be installed perpendicular to the frame. Here alternating layers of roofing felt usually fiberglass and hot applied asphalt are combined to create a long lasting roof system. A built up roof for example will typically include the built up membrane itself with or without gravel as well as some kind of insulation and cover board which will vary in thickness from roof to roof. As opposed to old built up felt roofing with joins new single ply waterproof membranes are now most commonly used.

When it comes to estimating the weight of an existing roof field verification of the in place construction is necessary. 8d ring shank nails should be used instead. A typical flat roof repair costs at least 350 400 and involves locating sources of leaks and patching the seams or holes. Pvc membranes are easy to maintain and repair.

The best weight for roofing felt is the 30 pound product because it provides thicker and stronger footing for roofers that does not tear out especially on steep roofs where footing is critical. The typical thickness range for sheathing is 3 8 to 3 4 inch. Of course how many rolls you need will depend on the size of the roof so ensure you measure correctly. Light weight shed roofing felt is not suitable for flat roof construction.

However depending on the severity of the damage and the type of material installed repairing a flat roof can cost as much as 600 800. Make sure the roof is clean dry and that all nail heads are flush with the deck. It s available in rolls that are 8m long and 1m wide with a thickness of 4 2mm mineral or 3 8mm sand. There are two types of flat roof.

Roofing felt s thickness is not a measurement of its depth because it is thin similar to heavy paper. The product can be used as a waterproofing coating on asphalt fibre cement sheeting concrete and bituminous roofing membranes. The most commonly used felts are 15 and 30 with weights of 8 and 20 pounds per 100 square feet respectively. The underlying deck must be constructed of moisture tolerant materials such as 18mm wbp plywood or suitable chipboard stirling board on treated timber joists.

Sheathing should be a minimum of 19 32 inch thick. As the single ply roofing association spra points out this type of flat roofing is strong durable completely sealed and usually lasts at least 25 30 years. Roofing felt s thickness is actually measured in pounds per square with one square equaling 100 feet of roofing material. A built up roof bur sometimes called a tar and gravel roof is a tried and true style of flat roof.