missing shingles on a roof

Missing shingles will ultimately lead to leaks

Published by Pawel Matonog

Contrary to popular thought, normal weathering of asphalt shingles will not cause sudden leaking in your home. The most common causes of leaks are as follows:

Missing flashing around chimney

Went up to do some repairs in this Toronto home and came across missing flashing across the front of their chimney

Flashings: the strips of metal around chimneys, sidewalls or junctions of a roof are most frequently to blame as the causes of leaks. These crucial areas must be watertight and expertly fitted to avoid water penetration. Installation of flashings is often the most difficult and time consuming part for a roofer and requires technical knowledge to complete properly; otherwise the flashing seal is not in place or will fail in time. Many roofing companies will fly through this portion of the project, not spending the adequate time on properly fitting flashings or, as I’ve recently come across on a repair job, not installing them in the first place, since they are so time consuming. Archer Roofing contractors take pride in a job well done and we take as much time as it takes to fit your roof with custom flashings.


new chimney flashing

New chimney flashing installed by Archer Roofing in Toronto

Close-up of new chimney flashing

Close-up of flashing detailing by Archer Roofing around chimney

close-up of chimney flashing in Toronto

All joints are custom fitted and water points of entry are sealed tightly by our expert roofers


missing shingles and plywood deck

Missing shingles on this Forest Hill roof have revealed corroded nails and an exposed roof deck

Missing shingles: damaged or missing shingles will leave the roof exposed to leaks and should be repaired without delay. During our annual inspections for homeowners, we frequently encounter areas with missing shingles due to blow-off or animal damage (especially in Toronto, with its ferocious raccoons). These bare patches on a roof will cause extensive damage if not fixed promptly.

racoon tore up roof

A racoon tried to make its nest in this Toronto home. The owners immediately experienced a leak which Archer Roofing promptly fixed

Self Help Tip: If you’re installing a few missing shingles on your own, make sure you note the alignment of the shingle cutouts, as well as the nailing location, as these areas are crucial to maintaining a watertight layer.  Without proper shingle alignment, leaks will be unavoidable, as water will ultimately find its way into these exposed crevices.  Overlying shingle tabs should always cover these areas.

Loose shingles or flashing can leak to unsightly leaks like this one in Central Toronto.

Loose shingles or flashing can lead to unsightly leaks like on this ceiling in Central Toronto

Inadequate ventilation: As mentioned in a few of my previous posts, inadequate ventilation can cause condensation accumulation, ice damming and frost buildup, which will in turn force water under the shingles and, over time, deteriorate a roof, leading to leaks. These problems can be easily prevented with proper ventilation spacing, as mandated by the National Building Code of Canada (Section 9.19) which we strictly adhere to.

If you’re worried about the state of your roof call Toronto’s best roofing contractors, Archer Roofing, to inspect your roof at 416-427-2437.