Installing roofing shingles varies depending on a few different factors. For example, is this a brand-new roof or are you repairing an existing roof? If you are reproofing an existing roof, then are you going to be tearing out the old shingles, or doing a layover, installing new shingles directly over old ones?
What type of shingles are you planning on installing; you can use asphalt three-tab shingles, the most widely used, and least expensive, wood shingles, metal materials from copper to aluminum to stainless steel, or slate tile. And then, you need to consider the configuration of your roof- is it a simple inverted V-shape, or does it have dormers, valleys and chimney or other roof penetrations to work around?
For the purposes of brevity, here we will be covering how to install 3-tab asphalt roofing shingles on a simple roof, over bare roof sheathing.
Installing asphalt shingles on new construction necessitates putting down a layer of 15-lb. roofing felt over the roof sheathing. Each row of roofing felt should overlap the previous one by a minimum of 2″ for weatherproofing. Lay out the felt strips vertically.
Using a staple gun, staple the felt underlayment to the sheathing. Begin at the eave edges and work your way up to the roof ridge.
Measure the length of the roof, and locate the exact center. Make a centerline mark along the eave with a chalk line.
Install the starter strip along the bottom edge of the roof. If you don’t have the special pre-cut type starter strip, you can just trim the tabs off a shingles and use them as your starter. The starter strip should overhang the eaves and gable end by 5/8″ or so.
The first shingle will be installed centered on the centerline chalkmark, just up against the top of the starter strip. Use a nailing pattern of four nails; along the nailing line, which should be about 5 5/8″ up from the bottom of the shingle, place one nail ½” in from each edge, and two more directly above the slots between tabs.
Make sure to drive your nails straight in rather than at an angle, since they can damage the shingles otherwise. Work you way to the end of the roof for in to the left and right, butting successive shingles up against the last.
Laying out the next row. Snap down a horizontal chalk line 5” above the top of the first row. This distance is called the shingle exposure, which is the height of the shingle that will be exposed to the elements. Because the standard asphalt shingle is 1 foot high, that means each row will overlap by seven inches the one below it. At this time, you can keep snapping horizontal chalk lines every 5 inches, until you reach the roof ridge.
Now you’re ready for your next row of shingles to be installed. Starting again at the centerline mark, locate the cut-out of the shingle over the center shingle middle tab’s center. Nail down the shingle with the same nail pattern used previously. Continue to place shingles in the second row until the end of the roof in each direction. For the third and subsequent rows, again begin at the center of the roof and place shingles as before. Keep going until you reach the roof ridge.
Begin on the other side of the roof in the same manner you began the first side, by laying down a centerline mark, and follow the steps until you reach the roof ridge.
To complete the roofing shingle installation, you will install a ridge cap row on the very top of the roof between the two sides. Special ridge cap shingles are available.
Start by bending a cap shingle over the ridge along the centerline of the shingle. You may need to bring the pieces indoors to warm them if the weather is cold.
Nail the shingle in place with one nail on each side 5 1/2 inches from the exposed end, and also 1 inch up from the shingle edge. Your next shingle should overlap to make a 5-inch exposure, as with the other shingles. Lay the overlaps opposite from prevailing winds direction.
Working on the roof can be hazardous. Take every safety precaution you can, and always use the utmost care while you’re working on the roof. Professionals use body-harnesses attached to a roof-anchor system by a lanyard. This allows them to safely focus on their work.
Things other than yourself can also fall off the roof and hurt people below. Let others know of the work overhead, and keep youngsters away from the work area.