How-to install a asphalt shingle roof
The new generation of asphalt shingles are a vast improvement. In addition to enhancing the appearance of all types of roof, they are easier to install and much more durable. These are laminate asphalt shingles made from a fibreglass mat, thicker and very wind-resistant. They are referred to as composition or architectural shingles.
Accurate measurements are essential for a successful installation. Safety ropes and harnesses are necessary, as is a roof scaffold system to ensure a safe working environment, particularly if you are installing shingles on a very steep roof.
Materials
- Roof felt (15 lb or 30 lb)
- Asphalt shingles
- Self-adhesive waterproofing membrane (underlayment)
- Valley flashing
- Chimney flashing
- Sealant
- Vent flashing
- Ridge vent
- Fascia board
- Roof flashing
- 1¼”, 1 ½”, 1 ¾” Galvanized nails
- Plastic roof cement
Tools
- Chalk line
- Crowbar
- Roofing knife
- Pneumatic roofing nailer
- Roofing hammer
- Roofing shovel
- Combination square
1. Remove the old shingles
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1.1 – Remove the old shingles and roofing felt with a roofer’s shovel. Pry out nails.
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1.2 – Sweep the roof as clean as possible and run a scraper over the decking to check for nails that might have been missed.
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1.3 – Inspect the plywood or particle board and replace any damaged or rotten boards. Panels must be at least ½” thick.
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1.4 – Nail down or screw in any boards that are raised or loose.
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1.5 – Install a metal or vinyl drip edge directly on the plywood the length of the eaves. Nail at 12″ intervals and lap each section by 2″. Use snips to cut the corners.
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1.6 – Verify that soffit and ridge vents are not obstructed.
2. Install the eaves protection membrane and cover the valleys
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2.1 – Install self-adhesive waterproof membrane 36-72″ wide (according to the applicable building code requirements) on all fascia boards.
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2.2 – Unroll and align the membrane so that it overlaps the metal drip edge by 3/8″.
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2.3 – Temporarily attach the roof membrane at a few equidistant locations.
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2.4 – Fold back the lower half and peel off the release film.
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2.5 – Reposition and press down to ensure good adherence.
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2.6 – Remove the temporary installations and fold back the upper half of the membrane.
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2.7 – Peel off the release film, reposition and press down to ensure good adherence.
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2.8 – Repeat to cover the eaves and fascia.
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2.9 – Lap the end joins by 6″ and the lateral joins by 3″.
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2.10 – Install roof vents and other roof elements on the decking.
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2.11 – Cover valleys with self-adhesive waterproof membrane. Begin at the lower section of the roof. Center a 36″ strip (of self-adhesive membrane down the centre of the valley) so that half of the strip (approximately 18″) covers each side. Overlap each section of the membrane by 6-12″.
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2.12 – Lay the self-adhesive membrane to extend 4″ up the sides of the chimney and to form a 12″ strip on the roof around the chimney.
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2.13 – Cover ridges and crests so that half a strip (approximately 18″) covers each side.
3. Install the underlayment
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3.1 – Install a felt or synthetic roofing underlayment over the entire surface. Start at the bottom of the roof.
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3.2 – Attach the underlayment to the roof with nails or roofing staples, spaced at every 8″ at the centre where sections overlap.
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3.3 – Advance the underlayment by 6″ on the self-adhering waterproof membrane along the fascia board.
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3.4 – Cover the entire surface of the roof, taking care to lap each row by 4-6″.
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3.5 – Advance the underlayment by at least 4″ on the valley membrane and by at least 6″ on the ridges and crests.
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3.6 – Extend 4″ around the chimney and at the intersection of all vertical surfaces on the roof.
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3.7 – Cut the openings for the chimney and vents.
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3.8 – Install the metal drip edge over the membrane on the fascia board.
