Flat Roof | Felt Roof Systems
Adrian Gibbs Roofing Contractors are specialists in applying felt roofs. Felt roofs are the traditional flat roof system common to many flat roofs throughout the UK.
Built-Up Felt Roof Introduction
Built up roofing felt is a composite of an absorbent sheet of organic or synthetic fiber that is impregnated/saturated and coated with a waterproofing agent such as tar or asphalt bitumen that prevents ingress of moisture.
Built up felt roofs consist of two or three layers of sheet felt materials that form a dense and impermeable barrier. The felt roof system is built up of multiple layers of high performance felts and mastic asphalt over an insulated timber or concrete flat roof deck.
There are several techniques for applying built up felt - depending on the materials used.
Roll & Pour
Hot bitumen at 220-240°C is poured on the roof and felt is then rolled over it. The bitumen is poured down the front of the roll to provide a continuous bead of molten bitumen across the whole width of the felt. The bitumen fills voids and when cold it provides a total contact adhesive bond to the layers and it seals joints at the laps.
Torch-On
Torch on uses specially designed felt that is heated with a gas torch. The technique is generally used for small to medium sized roofs and flat roof repair where the new material must be fused together with the old to ensure total lap security. The application is not suitable for direct bonding to timber and wood based decks or lightweight polyester base materials.
