I think I really messed up! I could use some help because this problem is driving me crazy. In the summer months my greenhouse was my oasis but now that the rainy season is here it's unusable with all the water getting in. The back of my garage had a low overhang the people before me used the space underneath for a dog run. I got the idea to remove the shingles and roofing up to the side of the building and replace it with SunTuf polycarbonate clear panels and make a greenhouse. The consistent rain is here and water is making it's way under the panels and dripping all along the back of my greenhouse. I bought some 8 inch aluminum sheeting and tucked one side under the shingles and it hangs over the plastic panela about 4 inches. Used some caulking at the shingle edge and put some rubber patch tape along the seam as well. It helped not at all. I don't know what to do. Water seems to pool at the little edge created where the two roofs meet. My neighbor said he would have put the panels under the roof supports but that would have made the space much shorter. I'm trying to avoid moving the panels and doing that at all costs. Any ideas for how to fix this without going that route are much appreciated. Having that greenhouse to spend time in during the long winter was going to be what got me through this winter now I just have a wet mess on my hands!