KM Roofing Edinburgh – Detail to a uPVC downpipe and watergate in lead, with lead flashing on a green mineral flat roof in Edinburgh. The lead flashing raggle is sealed with grey polysulphide lead mastic. Using a flexible lead sealant ensures a waterproof seal to the building and is superior to pointing with a sand and cement mortar. All roofing work by KM Roofing Edinburgh. KM Roofing Edinburgh are members of the National Federation of Roofing Contractors- NFRC and Flat Roofing Alliance (FRA).