Roofing Felt

Roofing felt is also known as underlayment. It is installed under the external roof to provide a secondary water-resistant barrier to ensure that rain does not permeate the roof and cause structural damage. It is measured by its weight or density and the choice of which roofing felt to use depends on the roofing material itself and the extent of the roof. Rolls of felt can be found in rolls which means it can be cut to fit the dimensions of the roof allowing for any projections like chimneys. Traditionally, roofing felt was made of tar-like substances, such as asphalt or bitumen, impregnated with an agent to make it waterproof. Nowadays, other materials are being used. Organic roofing felt is increasingly being installed while TPO (thermoplastic polyolefin membrane) is one of the latest technologies. It is lighter, strong and is less likely to tear during installation. The use of larger sheets means there are fewer seams so there is less chance of water damage. Roofing felt is of major importance when considering the installation or the maintenance of a roof no matter what the building. It is mainly used under the external roof but on structures like garden sheds, it could be sufficient for roofing purposes.