Layers Of Roof Construction

Here are the layers of a roof in order of application bottom to top.

Layers of roof construction.

Some roofers install a layer of waterproof shingle underlayment wsu over the existing shingles at the eave end as would be done for a roof laid on bare sheathing. 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. Decking most often made out of plywood this roof layer is installed over the framing in a typical roof install. Roof covering typically of flat and rectangular shapes and made of various materials such as slate wood flagstone plastic metal and composite materials.

Water shield is the next roofing layer that creates a water proof barrier where ice or water can buildup near the roof eaves. It provides structure by tying the trusses and joists together. Is this about right for my area. However some areas on the roof have up to five layers of shinles.

Roof deck is the roofing material that sits on top of the roof trusses. If two layers already exist you ll need to remove the old layers before installing a new layer of shingles. Some roofing felts are actually glued down. You can usually see the underside of plywood decking from the attic.

When it comes to estimating the weight of an existing roof field verification of the in place construction is necessary. Any more than two layers of shingles can be too much for the roof to handle even if the local building codes don t outlaw it. Most roof decking is made from sheets of plywood. For dimensional shingles being installed over a layer of existing dimensional shingles you should always use a 1 1 2 inch roofing nail.

The tear off quote is 4 000. The roof has varying number of layers with most areas having two layers of old shingles. These thick layers of roofing felt are installed by heating the back of the felt with a butane torch and then carefully applying it to the roof. It is a waterproofing layer made of regular felt stacked above the solid decking board and then completely covered by the shingles or other roofing materials.

In most areas building codes allow for up to two layers of shingles installed on a roof. 3 starter shingles a narrow row of asphalt roofing the starter strip is nailed to the perimeter of the roof with a bead of adhesive on top that grips the underside of the first course of shingles. Installing the roofing felt does take care but can go very quickly. However installing new flashings including special drip edge flashings made for reroofing will ensure a tight seal and a long life.

This synthetic layer which replaces felt paper covers the entire roof deck and is the second line of defense against leaks after the shingles. These applications are ideal for flat roofs or protective surfaces under roof level decks.