Whether you're building a new structure or repairing an older home, knowing how to shingle a roof can save you a serious investment, and protect your dwelling from the elements.
Step 1 - Prepare Safety
Before getting on the roof, equip a safety harness with a roof hook to prevent you from falling to the ground below. You may not end up needing them, but you're better off safe than suffering significant injury, or even death.
1.1—Sweep the roof deck of all dirt and carefully check the decking carefully so undesired nails, wood pieces, or other obstructions don’t end up underneath the underlayment.
Step 2 - Attach Metal Drip Edge
This is a profiled metal strip placed along the bottom of the eave to lead rain and melting snow away from the building, preventing water damage (Figure 1).
2.1—Place the drip edge on the edge of the decking boards or sheeting and wrap it around the very edge of the roof.
2.2—Slide it in position for a finger to fit in-between the metal drip and the fascia board of the eave. If it’s too close, suction will be created, leading the water back to the eave (Figure 2).
2.3—While maintaining that distance, nail it down starting at one end, every 16-inches or so, right up to the other end of the roof.
2.4—If you have to use more than one length for a straight run, overlap the two pieces by at least four inches at the joint and keep nailing as described above.
Step 3 - Attach Ice & Water Shield Membrane
Supplied in rolls, the backside of it is coated with an adhesive and covered with a protective peel-off film. The exposed surface of the membrane has a 3-inch band of tar at the top edge to seal the next row (Figure 3). This membrane is designed to form a watertight seal around the nails. Two rows of that membrane will likely be required for the full length of the roof at the bottom.
3.1—Since the edge of a roof is not always perfectly straight, you’ll have to snap a line on the roof deck at the width of the membrane. It will guide you to install the membrane straight and without wrinkles.
3.2—Unroll the bottom strip of membrane from the left rake edge removing the top half of the protective film underneath as you progress, and stick the membrane onto the roof deck up to about 3-feet from the other end (Figure 4).
3.3—Without pulling off any more of the film, lay the membrane flat and cut it so that it will cover up to the edge of the roof rake.
3.4—After removing the rest of the protective film, you can then staple the membrane down every 2 to 3-feet, on the band of tar to keep the wind from getting underneath.
3.5—You can now remove the bottom half of the protective film. The subsequent rows of underlayment will overlap the previous row to the printed line. Two rows of that membrane will likely be required at the bottom, with the rest of the deck covered with felt paper, every row stapled down as you go.
Step 4 - Attach Any Additional Drip Edges
4.1—After covering the deck, install more drip edges at both rakes of the roof.
Step 5 - Lay Starter Strips
The starter strips are an integral part of roofing to cover shingle joints and tabs cutouts. They also provide a strip of tar around the perimeter of the roof to hold the shingles down. They’re about half the width of a regular shingle with a strip of tar along the bottom edge (Figure 5).
A common practice, however, is to make the starter strip yourself from 3-tabs shingles cut in the length to remove the three tabs (Figure 6 ).
5.1—After cutting the tabs off, cut the length of half a tab from the rake end of the first starter strip to offset from the first-course shingles.
5.2—Put down that start piece on the roof edge, overlapping the rake and the metal drip by 1/4-inch, to lead the water away from the eaves.
5.3—Use 4 nails in each start strip piece, 1-inch from the top edge, to secure them in place. Cover the roof length and both rakes leaving the same overlap all around.
Step 6 - Lay the First Course Row with 3-Tab Shingles
6.1—You can now start the first-course row of shingles starting on top of the start strip, lining it up with the end and bottom overlap.
6.2—Once in place, secure it with roofing nails just below the adhesive tar strip (Figure 7 ), 1-inch (25mm) from the ends:
—Right above the two tab cutouts for a roof pitch between 15° and 60°.
—1-inch (25mm) over on each side of the tab cutouts for roof pitches above 60°.
6.3—Keep adding shingles to the first course to the full length of the roof using the appropriate method of nailing.
Step 7 - Lay More Shingle Rows
7.1—You can start the second row by cutting off the length of half a tab from the rake end of the first shingle in order to set it back that same amount from the joint of the underlying piece. The cut off sections will be used at the other rake end.
7.2—Keep building it up cutting off half a tab more every time you start a subsequent row creating a pyramid-shaped pattern for about 5 - 6 rows. With this method, you can nail down many more shingles before having to move over for the next batch.
Step 8 - Mark Subsequent Courses
Courses of shingles can also be completed one row at a time, drawing a chalk line every now and then to keep the rows parallel to each other.
Step 9 - Cap the Peak
When you reach the top on both sides of the roof, you'll want to cover the peak with a cap that will cover the shingles on both sides, past the tar strip.
9.1—You make the roof caps from regular shingle by cutting them in three sections, through the center of the tabs, then trimming each side at a slight angle, making the top narrower than the center. Make as many as 6-1/2 pieces for each shingle length of the roof peak.
9.2—Wrap the first piece across the peak at on end of the roof and nail down with a nail on each side on the top part of its tar strip. Wrap the subsequent cap pieces over the previous piece, covering the tar strip (Figure 8 ). The last piece at the other end will be from one of those pieces after the top black part is cut off leaving the tab part just below the tar strip. It can be glued on with a roofing pitch