Stop Water Going Behind Eavestroughs in Ottawa

Water running behind your eavestroughs and staining your soffit is one of the most common eavestrough complaints in Ottawa, and it almost always points to one of a few fixable problems. Ignoring it leads to soffit rot, fascia damage, and potential moisture intrusion into your attic space — especially dangerous through Ottawa's freeze-thaw winter when trapped moisture expands as ice.

Why Water Gets Behind the Gutter

The most frequent cause is improper eavestrough positioning. Your gutter should be installed so the back edge tucks up underneath the drip edge flashing — the thin metal strip that extends over the edge of your roof deck. If the drip edge is too short, missing entirely, or if the eavestrough was mounted too low, water sheets off the shingles, overshoots the gutter lip, and runs down the back side onto the fascia and soffit. This is extremely common on Ottawa homes built before the 1990s where drip edge installation was inconsistent.

The fix for a missing or short drip edge is installing new aluminum drip edge flashing that extends far enough to direct water into the gutter channel. This is a relatively inexpensive repair — $3 to $6 per linear foot for materials and $5 to $12 per linear foot installed in Ottawa. A good installer will slide the drip edge under the first row of shingles and bend it slightly into the gutter trough to create a reliable water path.

Clogged eavestroughs are the second most common cause. When leaves, shingle grit, and debris build up in your gutters — particularly common in treed Ottawa neighbourhoods like the Glebe, Sandy Hill, and Old Ottawa South — water backs up and overflows in every direction, including behind the gutter. Regular cleaning in late spring and late November prevents this. Professional cleaning runs $150 to $350 per visit in Ottawa, and seasonal packages covering both cleanings cost $250 to $600 annually.

Sagging or improperly sloped eavestroughs cause water to pool in low spots rather than flowing toward downspouts. Standing water eventually overflows at the weakest point. Ottawa's heavy snow loads accelerate sagging, especially if hangers are spaced more than 24 inches apart. Re-sloping or adding hangers is a straightforward repair costing $150 to $400 depending on the length involved.

Ice dams during Ottawa's winter create another pathway for water behind eavestroughs. When ice builds up at the roof edge during our 50-plus annual freeze-thaw cycles, meltwater has nowhere to go and backs up under shingles and behind gutters. Proper attic insulation to R-60 and adequate soffit ventilation are the real solutions to ice dams — no eavestrough modification alone will fix the root cause.

For the soffit staining you already have, a mixture of warm water, mild dish soap, and a soft-bristle brush removes most water stains from aluminum or vinyl soffit. Stubborn oxidation stains may need a specialized aluminum cleaner. If the staining has progressed to soft or spongy spots in wood soffit, you likely have rot that needs professional repair before the damage spreads to your roof structure. Connect with experienced eavestrough and soffit professionals through the Ottawa Construction Network directory at justynrookcontracting.com to get the problem assessed properly.