What Is a Drip Edge and Do You Need One With Ottawa Eavestroughs?

A drip edge is a narrow strip of angled metal flashing installed along the edge of your roof, and it is one of the most important but least understood components connecting your roof to your eavestrough system. In Ottawa's extreme climate, a drip edge is not optional — it is an essential part of a properly functioning roof drainage system, and the Ontario Building Code requires it on all new roof installations.

How Drip Edges Work With Eavestroughs

The drip edge sits under the bottom row of shingles and extends outward over the fascia board, creating a clean edge that directs water off the roof deck and into the eavestrough below. Without a drip edge, water running off the last shingle can wick backward along the underside of the shingle tab and drip behind the eavestrough rather than into it. This backward-wicking water soaks into the fascia board, roof decking, and soffit, causing rot, mould, and structural damage that is invisible until it becomes severe.

In Ottawa, the drip edge plays a critical secondary role during winter. During freeze-thaw cycles, meltwater flowing off the roof needs a clean break point where it drops into the gutter. Without a drip edge, meltwater clings to the roof edge and refreezes on the fascia, building up layers of ice that pull the eavestrough away from the house. A proper drip edge also prevents water from migrating under the ice-and-water shield membrane that Ottawa roofers install along the first 3 to 6 feet of roof edge as ice dam protection.

Drip edges come in several profiles. Type C (L-shaped) is the most basic, bending at a 90-degree angle over the fascia edge. Type D (T-shaped or kick-out) has an additional lower flange that directs water away from the fascia and into the gutter more effectively. For Ottawa installations, Type D drip edge is strongly recommended because it provides better ice dam protection and keeps water further from the fascia during heavy rain.

Material options include galvanized steel, aluminum, and copper. Aluminum drip edge costs $2 to $4 per linear foot for the material, with installation adding $3 to $6 per linear foot if done as a standalone project. When installed during a roof replacement, the cost is typically included in the roofing price or adds only $200 to $500 for a typical Ottawa home.

If you are getting new eavestroughs installed on a home that currently lacks a drip edge, ask your contractor about adding one at the same time. The eavestrough has to come down or be loosened to install the drip edge properly behind it, so doing both together saves labour costs. If your eavestroughs are being replaced during a roof replacement, the drip edge should absolutely be installed before the new gutters go on — this is the ideal sequence and the most cost-effective time to add this critical component.

Any reputable eavestrough installer will inspect your drip edge condition before mounting new gutters. You can find professionals who understand the relationship between drip edges and eavestroughs through the Ottawa Construction Network directory at justynrookcontracting.com.