Hello, we are remodeling our bathroom (upper level main bath) and would like to install one of the "tubular" skylight kits, since they are pretty inexpensive and seem to be reasonable easy for a non-pro to install. Our issue is this ... our roof is very pitched and has THREE layers of shingles on it. We are worried about rain, snow leakage ....It seems as though his could present some issues with the flashing thickness, etc. HAs anyone encountered this scenario? Does anyone have any recommendations as to one brand over another? Would it be beneficial to order a larger diameter tube over a smaller one? Any suggestions/help wold be greatly appreciated.