Measure the height of the shingles you are using. Use the chalk to make a mark at either end of the roof at this height.
Hold one end of the snap chalkline's string at one marking, and the other end at the other marking. Then snap the chalkline by lifting the string in the middle several inches off the surface of the roof deck and letting go. The resulting line will show you the height of the first course of shingles and will help you keep the shingles aligned.
Check the manufacturer's directions on the shingle package to see how many nails are required for each shingle, as well as where the nails should be placed. These factors will differ according to the shingles you are using. For example, if you are using Owens Corning standard shingles, you should use five nails per shingle, starting between two-to-three inches up from the edge of the shingle.
Place the first shingle at the bottom corner of the roof deck, using the chalk line as a guide. Use the information you discovered in Step 3 to nail the shingle to the roof deck.
Lay another shingle next to the first, and repeat the previous procedure to nail it in. If you are using wood shingles (such as cedar), leave 1/4 inch between each shingle to allow for expansion due to moisture. Continue until you finish the first course, or row, of shingles.
Snap a chalk line after each row to keep the shingles aligned horizontally. You can also snap vertical chalklines up the roof deck between each pair of shingles in the first course to keep the shingles aligned vertically all the way up the roof.
Things You Will Need
- Snap chalkline
- Galvanized roofing nails
- At the peak of the roof, or at either end, you may need to trim the shingles so they will fit correctly. You can use almost any cutting implement, such as switchblades or shears, to trim the shingles.
- Nail shingles on a warmer day for maximum adhesiveness. Avoid installing shingles during the coldest days of winter.