I wish the original owner had a regular shingled roof. In order to maintain the aluminum shingle warranty, Interlock had to service the roof. I scheduled 3 x 4-inch roof vents to be replaced with 6-inch roof vents. Additionally, I supplied the roof vents. The technician replaced the vents and left at around 1pm. Usually, you sign off on the work on completion and pay. This he left with no word and no sign off. From inside the attic I could see daylight from the side of one of the vents. This is the side which runs from the top to the bottom of the roof. I called 2 times the same to see if he was done w/ no call back. It's been a week and I've called 4 times with one call back to say I was looking inside the vent hole. I am not happy with this technician. I have checked the installation from the outside this weekend. The current and previous roof vent is curved at the top, the technician basically cut the one side straight up and put a ton of caulk between the shingle and the vent on both sides. The gap is about 1 to 2 cm between per side between the vent and shingle. I would never recommend an aluminum roof from this company due to the service issues.