First let’s talk about a common myth banded around regarding mastic asphalt repairs, beliefs that “new asphalt cannot be made to old” mastic asphalt is a complete rubbish. Mastic asphalt is in fact one of the ONLY materials that, with the right preparation and application that can be identified and rectified easily. Impact damage and movement cracks are readily seen in this totally seamless waterproofing.
A hot poultice of mastic asphalt can be applied around the defective area heating the old existing enabling to cut out a patch with a trowel down to roof structure. Equally, this can be achieved with a small hand-held battery grinder. Either option takes away the health and safety hazard of a gas bottle and torch and hot work permit.
Once the patch is removed, a break joint can be cut out using mastic asphalt as to lay 2 coats. Sheathing felt will be cut in to patch as a separating membrane. A first coat will be made good to first break joint, then when cold, top coat will be installed, warming and cleaning the old existing lifting and making good with a sand rubbed finish leaving flat and completely waterproofed.