Lapping Roofing Felt
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.
Lapping roofing felt. An alternative approach not widely used anymore is to seal all laps in the lower courses of roofing felt with lap cement or asphalt plastic cement. Roofing felt is essential to ensure your outbuilding is ready for all weathers by providing a waterproof cover to the building s roof. Step by step guide for felting a flat roof. These applications are ideal for flat roofs or protective surfaces under roof level decks.
Ideal for an apex flat or pent roof shed felt and roofing membrane are durable and perfect for a newly built structure or to re cover existing roofing material. In areas with extensive snowfall or windblown rain the best protection against leakage is to cover the entire low slope roof area with a bituminous membrane as shown in figure 2 4. In areas with extensive snowfall or windblown rain the best protection against leakage is to cover the entire low slope roof area with a bituminous membrane as shown in figure 2 4. The last layer should go over both sides of the roof overlapping both side covered in felt.
The overlapping felt creates a secondary barrier for moisture and wicks water away from the shingles above and the sheathing below. Installing the roofing felt does take care but can go very quickly. Hence this is why tiles are fitted on top of each other rather than sideways. An alternative approach not widely used anymore is to seal all laps in the lower courses of roofing felt with lap cement or asphalt plastic cement.
The roof felts are asphalt saturated and are manufactured with a high grade organic mat. Follow the 10 steps below in order to felt a flat roof. Roofing felt is required to overlap 2 inches over the lower felt course. This guide will use the more durable 30 roofing felt although you can use 15 felt.
Atlas roofing provides a complete selection of roofing felt underlayment. 30 saturated felt underlayment is specified for use as an underlayment between the roof deck and the shingles. Felt roof underlayment 30 saturated roof felt. Therefore a 2 inch overlap provides redundancy at the edges where the barrier is weakest.
Bitumen in terms of materials please note that there are several different weights for the roofing felt. For a flat roof the same applies start at the lower end first working to the higher end and this should resemble tiles on a roof.