The flat roof of a dormer is designed with a slight tilt so the water will run off the roof instead of sitting on top of the roof and cause long term damage. It is normally layered three times with a good quality green mineral felt. The felt comes in 600mm width rolls and when laid it is overlapped every 300mm over the whole roof then laid the opposite way overlapping 300mm again three times over to prevent any water damage. The underside of the felt is coated with a sticky tar which is heated together by a flame torch to stop any water getting into the loft. As this standard option is using fire (hot deck) to bond the felt together it is very dangerous and must be done by a professional flat roofer and not just done by a (tiler) roofer. Once the felt is laid on the roof a hot bitchaman is then applied over the final surface, completely sealing the area for around 17 to 20 years. This option will then need to be re done and could cost around £1500 to £2000 to have scaffolding erected and a new layer of felt laid by a professional flat roofer.

CHECK WITH YOUR COMPANY/BUILDER WHAT IS BEING USED ON YOUR ROOF AND IS THE ROOFER A PROFESSIONAL FLAT ROOFER.

The other option is to have a GRP ROOFING SYSTEM

This entry was posted on Monday, February 26th, 2007 at 6:22 pm and is filed under Roofs. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.