We had our siding replaced and roof replaced. The siding crew did a great job and has our sincere appreciation. The roofing crew was not prepared or trained to do the installation of the specialized synthetic shingles on our complex 12/12 pitch roof. This was not a project they were capable of doing well and it showed. I imagine they would do an acceptable job on a low angle roof with asphalt shingles. The high pitched roof required wearing a harness and tying in with ropes. They used heavy framing hammers to beat numerous holes into the roof decking near the ridge lines. This caused Sheetrock damage throughout the upper floor of our home. They could have mitigated that damage by using an electric hole saw instead of brute force smashing a hammer through 1/2 inch decking. The shingles the Project Manager recommended to us have an adhesive bead on the backside of every tab that is supposed to form a weather tight seal with the shingle below it. The PM claimed to have worked with this product in the past and that his crew was trained on how to install it. This turned out to not be true. Over 200 shingles were not sealed down properly and were sticking up with the underside exposed to the elements.They told us the roof needed a week of 80 degree temps to lay down flat and since it was late November we had to wait until the following year. We waited the entire summer of 2021 with plenty of days over 80 degrees and the shingles didn't lay flat. We attempted communication with them every month starting in May and every week starting in August. It is a year after the original installation and they have not come back to perform the warranty work on our roof. The lead installer finally came out a week ago (Nov 27) and used a heat gun to try and reheat the year old adhesive on the back side of the shingles that didn't seal down during the original install in 2020. He was able to get 30/40% of the non-sealed shingles to stick back down. The PM and other owner have not made the warranty work on our roof a priority on their schedule: instead they task their one roofing installer to work on other roofing jobs around Colorado. It is now December and winter has begun. GS Exteriors has still not honored the warranty on our roof and I have gone directly to the shingle manufacturer to try and resolve this problem. Very disappointing and frustrating experience working with GS Exteriors.