Yes — if leaves sit on your roof, they belong in your maintenance plan. Roof debris holds moisture against shingles, feeds algae and moss, and washes into the eavestroughs with every rain, undoing the cleaning you just paid for. A blow-off during a gutter visit costs $59 in 2026.
Why does roof debris matter if the gutters are clean?
Because the roof is upstream. A clean gutter under a loaded roof is a bathtub with the tap running: the next rain moves the roof's stockpile straight into the troughs. On canopy streets we see gutters refill within weeks of a cleaning — not because the clean was bad, but because nobody touched the reserve sitting in the valleys above it. Clearing both in one visit is what makes the job last the season.
Where does debris actually collect on a roof?
- Valleys — the internal angles where two roof planes meet channel and trap everything
- Behind chimneys, vents, and skylights, where wind eddies drop their cargo
- Low-slope sections that never build enough speed to shed leaves on their own
- Rear planes facing woodlots — Markham's Cornell and Berczy homes backing the Rouge collect loads the street never sees
Why never pressure wash a shingle roof?
Asphalt shingles are protected by their granule layer — it blocks UV and sheds water. A pressure washer strips granules by the handful, ageing the roof years in an afternoon, and many manufacturers void the warranty over it. Moss and staining have their own proper treatments. Debris removal needs exactly one tool used carefully: air. We blow the surface and valleys clear and never point pressure at a shingle.
When is the blow-off worth booking?
Pair it with a cleaning when any of these are true: you can see debris lines in the valleys from the street, your lot backs onto trees or a woodlot, your gutters seem to refill fast after cleanings, or your roof has low-slope sections that never look bare. As a $59 add-on the crew is already on the ladder with the setup — as a separate visit it would cost most of a cleaning, which is why we price it as an add-on and tell you to bundle it.
Debris left on a shaded roof is also how moss gets started, and roof debris removal in Markham pairs the blow-off with the gutter cleaning in one visit.
If your maples have already started dropping, ask for the blow-off in the same booking — one visit, roof and gutters both at zero, photos of each.
Frequently asked questions
Is it safe to walk on my roof to clear leaves?
Not recommended. Wet leaves, moss and granules make shingles slippery, and most roof falls happen during exactly this kind of quick job. Clear what you can from a ladder at the eave, or have it blown off by a crew.
Do leaves on the roof cause moss?
They help it. A mat of leaves holds moisture against the shingles and gives moss spores something to root in, especially on shaded, north-facing slopes.
How often should roof valleys be cleared?
With each fall gutter cleaning at minimum, and more often under heavy trees or on low-slope sections that never shed debris on their own.
Keep reading
- Moss on your roof and gutters: GTA causes and safe removal
- Shingle granules in your gutters: normal or a warning?
- Why your gutters overflow even when they're clean
- Roof debris removal: what is included and how it works
- Roof debris removal in Markham: local prices and booking
- Everything we do in Markham: neighbourhoods, trees and services
