Roof Deck Renovations When you upgrade or renovate an existing building, you may have to cut through a commercial roof deck to add exhaust fans, skylights, vents, or curbs for rooftop hvac units. Cutting into a commercial deck can be trickier than cutting a skylight into a residential wood roof. In fact, precautions are needed when you cut into the roofing membrane and when you cut the structural deck itself. Before taking any action, find out what type of roofing covers the deck you plan to penetrate. You need to know what's there so you can have the proper materials on hand to make the roof watertight after you make a test cut. Find out if the