Cover the remainder of the roof with No. 15 asphalt-saturated felt underlayment (some codes may require No. 30). Each layer overlaps the lower one by at least 2 in. Follow this step by nailing drip edge alongside rakes , on prime of the underlayment. As you probably did with the flashing, always lap upper pieces over decrease pieces. The felt keeps the roof deck dry earlier than shingles go on, protects against wind-driven rain as shingles fail and increases fire resistance. To install corrugated roofing, begin by cutting your panels to length with an angle grinder.
Run the underlayment previous the drip edge on the eaves, and trim off the additional with a utility knife. Once it’s easy, nail it down on the skin edges.
Next, pre-drill holes on the end and side ridges of the panels, spacing the holes 6 to 8 inches apart. Beginning on the outside fringe of your roof, place each panel directly onto the purlins which might be hooked up to the roof trusses.
Then fold the flashing over the peak and canopy the minimize ends with self-stick underlayment.Roof valleys channel a lot of water, in order that they need extra protection. Start by putting in self-stick underlayment on the decking. This course of is much simpler with two people. Cut the underlayment to size , and peel off the complete plastic backer. With an individual on each end, fold the underlayment in on itself, sticky side out. Try to push it down into the crease of the valley as tightly as attainable. If this self-stick ice-and- water underlayment bridges either side of the decking, leaving a spot beneath, it may tear once you put in the steel valley flashing.
Screw down the panels using the pre-drilled holes, then continue across the roof till it is completely covered. Install the shingles up and midway past the vent hole or stack.