code compliance
Under the National Building Code of Canada the installation of windows, doors, and skylights shall conform to CSA A440.4:19.

There are four essential characteristics of a code-compliant pan flashing system
In order to better understand how to comply with this standard, it is important to define the role of flashings. Flashings are fixed to a building’s barrier against the elements before installing windows. Flashings prevent water from penetrating horizontal joints, which redirects water outside. For flashings to be effective, they must:

1. It has an outward slope of at least 6%

2. It is in a continuous piece

3. It extends at least 6 mm beyond the underlying covering

4. It prevents water from entering the walls to the lower corners of windows and doors

1. It has an outward slope of at least 6%

2. It is in a continuous piece


3. It extends at least 6 mm beyond the underlying covering
