Roof pitch is expressed as rise over run. An 8/12 pitch means the roof rises 8 inches for every 12 inches of horizontal distance. That's a 33-degree angle. For context, most GTA homes are 4/12 to 6/12. At 8/12, you can't stand on the roof without sliding.
We re-roofed a two-storey colonial in Whitby with this pitch. The job taught the homeowner something and reminded us of something.
What the homeowner learned
When we stripped the old shingles, there was no ice-and-water shield. None. Not at the eaves, not in the valleys, nowhere. The original installer — whoever they were — had used only 15 lb felt paper across the entire roof deck.
Ontario Building Code requires ice-and-water shield a minimum of 3 feet up from the eave on any sloped roof. This house had zero. On a steep pitch, water moves fast, which partially masks the problem — it sheds before it can back up. But in a hard freeze with ice damming, there's nothing stopping water from getting under the shingles and into the decking.
The homeowner had owned the house for 9 years with no leaks. They were lucky. The previous owner probably had no leaks either. It would have caught up eventually.
What the pitch changes about the job
Safety equipment. Below 6/12, our crew works in soft-soled boots with standard harnesses. Above 6/12, we add roof jacks — temporary brackets nailed into the decking that hold a plank you can stand on. On this 25-square roof, we used 40 roof jacks. Setting and removing them adds roughly 3 hours to the job.
Shingle behavior. Shingles on a steep pitch are more exposed to wind uplift. Gravity helps water shed, but wind catches the bottom edge of each shingle like a sail. We hand-sealed every starter strip and used 6 nails per shingle instead of the standard 4. That's an extra 4,000 nails across the roof.
Material handling. Bundles of shingles weigh 70 lbs each. Carrying them up a ladder and across a 33-degree slope takes more time and more people. Bundles on a steep slope slide if you set them down wrong. We stage everything on the roof jacks.
The numbers
This 25-square job took us a full 2 days. A similar-sized roof at 4/12 would take 1.5. The safety setup, hand-sealing, and extra nailing pattern add about 20% to the labour. Material cost was the same — the premium is in the time.
We added ice-and-water shield 6 feet from every eave and through all valleys, installed IKO Cambridge in Weatheredwood, and ran new 5-inch seamless aluminum eavestrough. The homeowner now has a roof that's actually built to code — and beyond it.
What to ask your roofer
If your home has a steep pitch, ask specifically: how do you handle the slope? If the answer is "same as any roof," that's a red flag. Steep roofs require different safety practices, different nailing patterns, and more time. Any quote that prices a steep roof the same as a low-slope roof is cutting one of those corners.