- 1). Assess the conditions of the existing shingles. If the old layer of shingles lay flat with no protruding segments or void areas it may be suitable for shingling over. If there are multiple layers of existing shingles, they should be removed before applying new shingles.
- 2). Nail a starter roll, a 12-inch wide roll of asphalt material, along the eave edge of the roof. Nail it in place with 1 3/4-inch galvanized roofing nails spaced about 1 foot apart.
- 3). Place a row of shingles side-by-side along the edge of the starter roll and nail in place with 1 3/4-inch galvanized roofing nails placed in appropriate spots as designated in the shingle instructions..
- 4). Continue adding courses of shingles working up the roof. Each course covers the top portion of the lower course to the point just above the notches in the shingle. This covers the nails of the previous course. Repair any shallow low spots in the existing shingles by placing a shingle scrap in the low spot. Use roofing tar to hold the scrap in place..