Why does water drip behind my eavestrough instead of flowing into it on my Kanata home?

Water dripping behind your eavestrough instead of flowing into it is one of the most common eavestrough complaints in Ottawa, and the good news is that it almost always comes down to one of a few fixable causes. The problem is not your imagination — water running down your fascia board and behind the gutter is actively damaging your home every time it rains, so it is worth diagnosing and correcting promptly.

The Most Likely Culprit: Eavestrough Position

The single most common cause of this problem is that the back edge of the eavestrough has dropped away from the roofline, creating a gap between the gutter and the fascia board. In Ottawa's climate, this happens regularly because of the extreme freeze-thaw cycle the region experiences — 50 or more times each winter, hangers are stressed by ice loading, snow weight, and thermal expansion and contraction. Over time, hangers loosen, the gutter sags slightly outward, and that gap opens up. On a Kanata home that has gone through even five or ten Ottawa winters, this kind of hanger fatigue is completely normal.

The second major cause is the drip edge flashing — or the absence of it. Drip edge is a thin metal strip installed along the lower edge of the roof deck, under the shingles, that extends out over the back lip of the eavestrough. When drip edge is properly installed, water sheeting off the roof is directed into the gutter. When drip edge is missing, incorrectly installed, or has shifted over time, water follows the underside of the shingles by surface tension and drips straight down behind the gutter onto the fascia. Many older Kanata homes built in the 1980s and 1990s were constructed with minimal or improperly lapped drip edge, and this is a very frequent finding on homes in that era.

A third possibility is that your eavestrough has been installed too low relative to the roof edge. The back lip of the gutter should sit high enough that the shingle overhang directs water into it — the general rule is that the gutter should be positioned so that a line extended from the roof plane would land roughly in the middle of the gutter opening. If the gutter sits too far below the roofline, even a properly installed drip edge cannot compensate.

Ottawa-Specific Considerations

Kanata's mix of housing stock — from 1970s bungalows near Beaverbrook to newer two-storey homes in Bridlewood and Emerald Meadows — means the root cause can vary by age and original construction quality. Homes with steeper roof pitches throw water with more velocity, making proper positioning even more critical. Ottawa's heavy summer thunderstorms, which can dump 30 to 50 millimetres of rain in an hour, overwhelm a misaligned gutter quickly and make the problem very visible.

Ice can also physically pry the back of the eavestrough away from the fascia during winter. If you noticed the problem appearing or worsening after last winter, ice loading is a strong suspect.

What You Can Do

From ground level, look along the back edge of your eavestrough where it meets the fascia. If you can see daylight between the gutter and the fascia board, or if the gutter appears to be tilting outward at the top, that confirms a positioning or hanger issue. Check whether your shingles have a metal strip visible at the lower edge — that is your drip edge. If you see bare wood or roofing felt instead, drip edge may be missing entirely.

Minor hanger tightening on a single-storey section is a manageable DIY task for a confident homeowner with a sturdy ladder. However, correcting drip edge requires lifting the lower course of shingles to slide new flashing into place — this is roofing work that should be done by a professional to avoid voiding shingle warranties or creating new leak points. Repair costs for this type of correction typically run $150 to $400 depending on the linear footage affected.

If your fascia board has been getting wet behind the gutter for some time, check it for softness or rot — water-damaged fascia needs to be replaced before new eavestroughs or hangers are installed, adding $12 to $25 per linear foot to the project.

For help finding an eavestrough professional in the Kanata area, browse the Ottawa Construction Network directory at justynrookcontracting.com — it is a free resource where you can find and contact local contractors directly. Getting two or three quotes is always a smart move before committing to any repair work.