Well, not everything I did was a mistake but there were more than Id like to admit. I do a lot of my own building and am making a lot of repairs to my current house and a log cabin I have. When I did a lot of roofing & siding work I assumed water would flow down and away so thats how I built everything. Along comes winter and the dreaded ice dams and now water flows uphill and under everything to then leak into the living spaces. I pulled some vinyl siding off to put on an addition and after only a few years enough water had gotten behind the siding and even the house wrap that it rotted away some large sections of OSB. I found the source of leaks to be where water ran down the sides of some window J-channels and where a sloped roof met an outside wall. I pulled off everything, made the repairs and then put all the trim back with healthy does of this sealant and the leaks are now gone and ice cant push up under it. I also use the clear around my wood stove pipes & roof flashing and it seals them tight so no water running down the pipe onto the stove when strong winds are pushing heavy rains. Im putting flashing over all the exposed wood fascia and this stuff ensures no water gets under it. if you vinyl siding you are likely getting water damage near the windows so don't assume that because you don't see it its not happening. Ive no gone through about a dozen tubes of this stuff over the past few years and never had a problem with it and have stuck a large nail in open tubes and since its flexible the nail comes out easily and the product is still usable. Its also a good adhesive so I can attach flashing with a minimum of exposed nail and/or screw heads. For exterior work its the best product Ive found at a reasonable price. Ive even had success with it on sealing gutter leaks in the connectors.