With this job, we covered the old existing flat roof with a new 2 layer flat roof system. Stage 1: Sweep and clean down all of the main flat roof. Stage 2: One coat of black flat roof primer, which we left to dry. Stage 3: One layer of stick down bonding felt, stuck down to the main flat roof. Stage 4: Second layer of finishing, layer of felt stuck down with a hot torch gun to finish. The Felt comes in four different colours to choose from.