Retrofit a Flanged Window: Flash and Trim the Window

This video series features step-by-step instructions for a leak-free, energy-efficient window replacement.

See how to build window casing and use that casing as a template to cut back existing siding before you install the new window.

Learn how to clean the existing rough opening and inspect for damage before installing the new window.

Watch as builder Bill Robinson applies sealant to the window flange; checks the window for plumb, level, and square; and fastens the flanges to secure the window.

Bill Robinson demonstrates how to use a combination of materials to flash over the flanges before he installs the pre-built casing over the new window.