We purchased a house this April in Pennsylvania. We hired a reputable inspection firm to do the inspection. We purchased the house, mainly because it needed relatively little work. In fact, the inspector mentioned the roof was relatively new and was, by his estimate, less than 5 years old. However, several weeks ago we noticed water stains and water dripping from our master bathroom. The roofer we hired to fix the leak cut out 2 5x5 sections of the roof. It was discovered that the plywood under the shingles were covered in mold. Furthermore, he mentioned that while the shingles were new, the plywood was warped, discolored, and cracked namely because poor ventilation had caused the plywood to warp and crack from heat. I have never sued anyone but feel the inspection company should have discovered that the plywood under the shingles was visibly warped, cracked, discolored, and festered with mold. The inspector did climb into the attic, but only enough to poke is head up there. I also have a sneaking suspicion the seller of the house failed to disclose this because there's obvious evidence in the master bathroom, where it has been leaking, that the ceiling had been patched in several place. At this point, the roofer is quoting me $9000 to replace the plywood and shingles. Do I have any legal recourse? What should I, as the homeowner, do in order to prevent the mold from spreading? I have a ridge vent running the length of the roof. 2 foot soffits on either side of the house and a gable vent. I can't see how ventilation is a problem but according to the roofer it is.