I added a new roof addition to a portion of my house and decided to have Gutter Helmet (R-trade mark) covers installed. On the front portion of roof (12/12), they slid the top of the cover up under the shingles. Makes sense. On the back portion of roof, which is a long 4/12, they attached the top of the covers, with screws, directly on top of the shingles. Sounds odd to me. The installers said this is fine and will not leak. I e-mailed Gutter Helmet and received no response. I'm in upstate NY. Any thoughts?