Me too. In Australia I had a solar pool heater array glued to my corrugated iron roof to avoid extra holes. The installers were reluctant, so I put a big blob of silicone mastic on the roof and also a big blob of polyurethane mastic. A week later I asked them to come and try pulling them off. The polyurethane won. So they glued it with 3M 5200 polyuretahne mastic and started doing that on other installations. I intend to try that with solar here at some stage.