How do they make sure water won't leak in around the new windows?

Proper water sealing around new windows involves multiple layers of protection, starting with flashing and weatherstripping, then adding sealants and proper drainage systems. Professional installers use a comprehensive approach to create a watertight seal that protects your home for decades.

The most critical component is flashing installation. Before the window goes in, installers apply a flexible membrane or metal flashing around the rough opening, especially at the bottom sill and corners where water typically tries to enter. This flashing acts like a raincoat for your wall, directing any moisture that gets behind the siding safely away from the interior. Quality installers also use sill pan flashing at the bottom of the opening - this creates a sloped surface that channels water outward rather than letting it pool against the foundation.

Weatherstripping and sealants form the next line of defense. Modern windows come with factory-installed weatherstripping around all moving parts, but the installer must properly seal the gap between the window frame and the house structure. They'll use high-quality polyurethane or silicone caulking on the exterior, while leaving the interior side unsealed or using vapor-permeable sealant to allow moisture to escape from inside the wall cavity.

In Ottawa's climate with freeze-thaw cycles, proper drainage is especially important. Professional installers ensure the window sill slopes away from the house and install weep holes in the bottom of the window frame. These small openings allow any moisture that does get into the frame system to drain out rather than accumulating and potentially freezing.

The installation sequence matters tremendously - flashing must go on before siding, sealants need proper cure time, and everything must be installed in the right weather conditions. This is why professional installation with proper warranties is so important for long-term water protection.

For a free estimate on properly sealed window installation, request a quote from Ottawa Window Pros - we guarantee watertight installation with full warranty coverage.