The Job Before the Job

Most people think roofing starts when the first shingle goes on. It does not. A shingle install starts the day you strip the old roof and ends when the last ridge cap is sealed and the gutters are clean. Everything in between is setup, and skipping setup is how roofs fail in five years instead of lasting twenty-five.

Skill level: This is a professional-grade job. Even experienced DIYers underestimate the physical demand and the precision required.

Typical timeline: Two to four days for an average home (roughly 15 squares).

Materials cost (DIY): $2,500 to $4,000 depending on shingle quality and accessories.

Professional installation: $6,000 to $10,000+ for full tear-off and re-shingle in the Fraser Valley.

Step 1: Tear Off Down to Bare Deck

Every roof we do starts with a complete tear-off. I learned this the hard way -- when you layer over old shingles, you cannot see the damage underneath. Soft spots, water staining, delaminated sheathing. It all hides under the old layer until the new roof is already failing.

How we approach it:

1. Start at the ridge, work downward. Shingles overlap going down, so stripping from the top lets you peel in the direction of the overlap.
2. Pull every nail. A nail left behind is a bump under your new underlayment and a potential tear point.
3. Inspect the deck once it is bare. Walk the entire surface. Push down with your foot. Soft spots mean rot. Water stains mean past leaks. Replace any section that is not solid.
4. Sweep the deck clean. No debris, no leftover granules, no nails. You need a flat, dry surface.

Johnny and I have pulled off roofs with three layers of shingles stacked up. Three layers hiding twenty years of moisture damage. The homeowner thought they were saving money each time by going over the old. They ended up paying for a full deck replacement on top of the re-shingle.

Step 2: Drip Edge Along the Eaves

Drip edge is a small piece of bent metal that makes a big difference. It directs water off the deck edge and into the gutter instead of running down the fascia and rotting it out.

1. Position flush with the fascia -- half-inch overhang into the gutter trough.
2. Nail every 12 inches along the top edge.
3. Overlap joints by 2 inches.

The key detail: at the eaves, drip edge goes on before the ice and water shield. At the rakes, it goes on after the underlayment. Get this order wrong and water finds a path behind the metal.

Step 3: Ice and Water Shield

This membrane is your last line of defense. It self-seals around nail holes and blocks water that gets driven upward by wind or backed up by ice.

BC building code requires a minimum of 36 inches up from the eave. In the Fraser Valley, where heavy rain and freeze-thaw cycles hammer roofs from October through March, we run 72 inches. The extra material costs a few hundred dollars. The water damage it prevents costs thousands.

1. Peel the backing and press it to the deck. Work out any wrinkles as you go.
2. Overlap courses by 6 inches.
3. Cover every valley, chimney, skylight, and pipe penetration. These are where leaks start.

Step 4: Synthetic Underlayment

We use synthetic on every roof. Felt paper absorbs moisture, tears easily, and buckles. Synthetic lays flat, sheds water, and survives exposure if weather delays the shingle install.

1. Roll horizontally from eave to ridge. Overlap the ice and water shield by 6 inches.
2. Overlap each course by 6 inches.
3. Nail or cap-staple every 12 inches at seams, every 24 inches in the field.
4. Keep it tight and smooth. Wrinkles telegraph through the finished shingles.

Step 5: Rake Drip Edge and Valley Flashing

Rake drip edge goes on over the underlayment at the gable ends. Same nailing pattern -- 12-inch spacing, 2-inch overlaps. Water hits the underlayment, runs down, and the drip edge channels it off the edge.

For valleys, we use the open valley method with metal flashing. Center a 24- to 36-inch piece of painted steel or aluminum in the valley. Nail along the edges only -- never nail through the center of valley flashing. Seal all lap joints with roofing cement.

Step 6: Starter Strip and Chalk Lines

The starter strip is a narrow shingle that runs along the eave and the rake. Its adhesive strip bonds to the bottom edge of your first course and seals it against wind uplift. Without it, the first row of shingles has nothing holding the bottom edge down.

Once the starter is on, chalk lines go down. This is where the precision matters.

1. Measure your shingle exposure. Most architectural shingles call for 5-5/8 inches.
2. Snap horizontal lines every two to three courses. These keep your rows straight across the full width of the roof.
3. Snap vertical reference lines every few feet. These keep your offset pattern consistent.

I watched the shingler I learned from snap chalk lines with surgical precision. It seemed excessive at the time. Then I saw what happens when someone runs shingles without lines -- the courses drift, the cuts get inconsistent, and the finished roof looks crooked from the street. Lines are the difference between a roof that looks right and one that does not.

Step 7: Shingling -- Course by Course

This is the part everyone pictures when they think about roofing. And it is the part where nail placement separates a roof that lasts from one that blows apart in the first windstorm.

Nail placement -- the single most important detail

Every shingle manufacturer prints a nailing zone on their product. The nail has to go through the reinforcing mat, just below the adhesive strip. That is the zone. Here is what goes wrong when you miss it:

• Nail too low (a "low nail"): It punches through the exposed face of the shingle below, creating a hole where water enters. This is the mistake that voids the most warranties.
• Nail too high: It misses the reinforcing mat entirely. The shingle hangs there by friction alone until the wind catches it.
• Nail over-driven: The head crushes through the shingle surface instead of sitting flush. Now you have a dent that collects water.
• Nail under-driven: The head sticks up above the surface and creates a bump under the shingle above. That bump prevents the adhesive strip from sealing.

No low nails, no bad cuts. That is the standard Johnny and I hold ourselves to on every roof.

Course installation

1. Lay the first full shingle on your chalk line. Half-inch overhang past the drip edge at the eave and rake.
2. Drive 6 nails per shingle -- one inch from each end, the remaining four evenly spaced across the nailing zone.
3. Work across the eave, completing each course before starting the next.
4. Offset each course by at least 6 inches. This staggers the joints so water never has a straight path downward.
5. Check alignment against your chalk lines every few rows. Drift happens gradually and is hard to fix once you are six courses up.

Cutting at valleys and rakes

Clean cuts matter. A ragged valley cut looks bad and leaves loose granules that clog gutters. A sloppy rake cut lets wind catch the edge.

• Valley cuts: Snap a chalk line 2 to 3 inches from the valley center. Cut along it with a sharp hook blade. Clip the upper corner at 45 degrees to direct water down the valley instead of across the cut edge. Dab roofing cement under the cut edge.
• Rake cuts: Overhang the drip edge by half an inch. Cut from the face side using a straight edge for a clean line.

Step 8: Penetrations and Chimney Flashing

Every pipe, vent, skylight, and chimney is a potential leak point. Flashing these correctly takes patience. Rushing through flashing is how roofers create callbacks.

Plumbing vents: Slide a rubber pipe boot over the pipe. Nail the flange. Shingle over the top and sides of the flange, leaving the bottom exposed so water runs over it. Seal the pipe-to-boot junction.

Chimneys: Base flashing at the downslope face. Step flashing up each side -- one piece per shingle course, woven into the courses. Counter flashing embedded in the mortar joints, overlapping the step flashing. A cricket (saddle) on the upslope side of any chimney wider than 30 inches to divert water around it.

Step 9: Ridge Cap

Ridge caps seal the peak and they are the last thing the eye catches from ground level. Sloppy ridge work stands out.

1. Start at the end opposite the prevailing wind. Wind should blow over the laps, not under them.
2. Overlap each cap by 5 to 6 inches.
3. Nail each side -- 1 inch from the edge, both sides.
4. Seal the final cap with roofing cement. The last cap has no overlap covering it, so cement keeps water out.

Step 10: Walk the Roof and Inspect

When the last cap is on, the job is not done. Walk every section. Look for:

• Lifted tabs or unsealed edges
• Exposed nails (there should be zero)
• Crooked courses or drifting alignment
• Gaps at flashings or improperly sealed penetrations
• Debris in gutters or on the deck

Photograph the finished roof from every angle. Those photos serve as warranty documentation and give the homeowner a record of what is under the surface.

Mistakes That Cost Homeowners Money

After 500-plus roofs, these are the failures I see most often when inspecting work done by other crews or past DIY attempts:

Low nails. A nail that lands below the adhesive strip punches through the exposed portion of the shingle below it. That is a leak point on day one. Every nail needs to land in the manufacturer's nailing zone, and the gun's pressure needs to be dialed in so the nail sits flush -- not driven through, not standing proud.

Bad cuts at valleys. Ragged cuts, no corner clips, no cement under the edge. Water follows the path of least resistance, and a rough-cut valley gives it a path right under the shingle.

Skipping ice and water shield. Some crews skip it or run it only 36 inches up the eave to save material. In the Fraser Valley, that gamble usually costs the homeowner a water damage claim within the first few winters.

No starter strip. Without it, the first course has no adhesive bond at the bottom edge. The first serious wind lifts the eave-row shingles and water gets behind them.

Layering over old shingles. Saves a day of tear-off labor. Hides every problem underneath. Adds weight the structure was not designed for. Voids the new shingle warranty. There is no scenario where this is a good trade.

Why Boilermaker Precision Matters on a Roof

Johnny and I are both Red Seal boilermakers. We came up in the oil sands, where a weld that is a millimetre off gets ground out and redone. A bolt torqued too tight or not tight enough gets flagged. There is no "close enough."

That mindset followed us when we started Dads Roofing in 2021. A nail in the wrong zone is not close enough. A shingle that drifts a quarter inch off the chalk line is not straight enough. A valley cut with a burr on it is not clean enough. When you hold yourself to a standard where everything is either right or it gets fixed, the finished product reflects that -- and the roof performs for decades instead of failing at the ten-year mark.

When to Call a Professional

This guide covers the full process, but I will be honest: most homeowners should not shingle their own roof. It is dangerous work at height. It is physically brutal. And mistakes that seem minor -- a nail a half-inch too low, a course that drifts -- turn into leaks and blown-off shingles that cost more to fix than the original installation.

If you have a simple, low-slope section and you want to learn the trade, start by packing bundles for someone who knows what they are doing. Watch. Learn where the nails go. Learn how they handle valleys. When you understand the why behind every step, the doing part falls into place.

Need a shingle install done right? Call (778) 539-6917 or visit us in Agassiz, BC. We cover the entire Fraser Valley -- Hope to Abbotsford and every community in between.