The roofing company I hired finished applying Polyfresko bitumen on my garage, and instead of welding the beginning and end of new layers at the edges, they overlapped one layer over another by about 6 inches, resulting in a “hump” of overlapping layers.
Is this normal? I thought the membrane would be completely flat. First example:
The overlap can be seen from the driveway:
Where one sheet ends, they overlapped the new sheet by about 6 inches instead of welding at the edge of the sheet: