Roof installation

Considering safety issues in applying the roof materials is very important. Injuries may happen when cutting roof materials and respiratory hazards of asphalt-based materials.

The first step of roof installation is preparing the roof deck. The roof underlayment and waterproofing membrane (if required) are installed as well as drip edge and the flashing for eaves and valleys. Usually the process starts by installing the drip edge and valley flashing. The flashing is secured to the roof with nails every 6 to 8 inches. The nails head is covered with asphalt. The underlayment and waterproofing membrane are installed to the roof deck with nails. For the places with the risk of heavy snow, protection against ice dam is necessary. Eave flashing is used to prevent water backup behind any ice dam.

The next step is installation of roof shingles. A standard terminology is used in placing the shingles. Exposure is the distance between two courses of roof shingles. Top lap is the height of the shingle minus exposure. Head lap is the distance between top of the shingle in one course to bottom of shingles of the two top courses.

Roof shingles may be placed left to right or right to left depending on the preference of the roofer. It can also start from the middle and continue to both ends. The common method is placement of starter row with the tabs of the regular course of shingles. The exposure part of shingle is cut off and applied in the starter course along the roof perimeter. A course of full shingle comes over the starter course. End of the top course should have 6 inches offset from the one below. Fastening the shingles are based on the recommendations provided by the manufacturer. After applying the roof shingles in both sides of the roof, the roof ridge cap is installed. The ridge cap will finish the roof shingles and cover the nails of the last course.