How To Put Roofing Felt Down

These applications are ideal for flat roofs or protective surfaces under roof level decks.

How to put roofing felt down.

If this felt is more than a temporary waterproofing measure apply roofing mastic using a caulking gun. Press down on the end of the bitumen to bind it to the flashing. Pull the trigger of the gun and move the nozzle around the circumference of each nail. Roofing felt can get wet and still maintain its integrity as long as it is not exposed to the elements for more than a few days.

Make sure the flashing can t move at all. Roofing felt is comprised of a base made from natural materials such as wood cellulose or synthetic ones such as fiberglass or polyester and then coated or saturated with a protective coating such as bitumen asphalt which repels water but still allows the product to breathe. Some roofers prefer to attach felt underlayment with 1 inch roofing nails or special nails with plastic washers but most codes allow staples which are easier to drive. Roll out about 10 feet of felt and fasten with staples or roofing nails with plastic washer heads.

Lightly heat the flashing and the end of the roofing sheet enough to begin melting the bitumen. Put fasteners at least every 8 inches. Step on the end of the sheet pressing down hard to force the melted bitumen into the gap between the flashing and the roof. Use a construction stapler or a hammer.

Or you could paint it over with a rubber mastic liquid but this could be more expensive than a second covering of felt. Cover all nail heads with roofing mastic for long term roofing. Installing the roofing felt does take care but can go very quickly. 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 will break down in sunlight and with large amounts of ongoing. Before applying roofing you ll need to cover the sheathing with roofing felt also often called tar paper most local codes call for using 30 pound felt.