After a windstorm we had last night, a handfull of ashphalt shingles have blown off my house. The house is just over 2 years old. I have 2 questions. One, when installing shingles, is there a standard for spacing of shingles between each layer? Two, how does one go about getting the shingle manufacturer to own up to its guarantee on its shingles if the shingles were installed correctly? I believe the shingle manufacturer is Certainteed.