Henryk L

Laying a few square meters is a project that shouldn't be underestimated. The process is complex if you want to do it properly. Cutouts are time-consuming. 1) Sharp utility knife blades are essential. Turpentine substitute helps with cleaning, but regularly snapping and replacing the blades is significantly better. A sharp blade glides almost effortlessly through the foam without tearing the aluminum surface. 2) The panels are much easier to work with when they are very cold. 3) Mark the cut, cut through the thick foam, then fold the panel so that the bitumen breaks. Trace the fold on the other side (with a marker) and reposition the utility knife there. This works very well, as you don't have to cut through the bitumen. 4) If you want to do it properly, you'll need quite a lot of aluminum tape. I used one roll for every 3 square meters. It's best to stick the tape on and only tear off the aluminum strip, leaving the white backing film intact. This eliminates the fiddly process of separating the tape from the backing film again. 5) Apply a strip of aluminum tape to the cut edges along the outer edges of each surface, then carefully fold it over and stick a second strip all the way around the surface, widening the narrow adhesive strip. That'll hold!