Installing Windows With Flange
- Installing a Flanged Window - Preparing the Opening 1) Basic Window Styles. 2) Window Glazing. 3) Door Options. 4) Installing and Replacing Doors. 5) Fitting a Door Blank. 6) Framing for a Window. 7) Installing a Flanged Window. 8) Replacement Window Insert Units. 9) Skylights & Roof.
- Step 1 - Insert the Window. In order to install the window, you will need to have already created a basic opening in the side of the wall. This is known as a rough opening, and should be cut to the dimensions described in the window's instruction manual.

Nailing fins are flanges on the outside of vinyl and aluminum windows that sit flush agains the sheathing when the window is in place.

From waterproofing to insulating, Tom Silva's step-by-step guide to putting in a new window

Windows do a lot: help establish a home's visual character, let in light and air, and frame views from inside. But if not installed correctly, they can become unwelcome avenues for water. 'Rot around windows, even in relatively new houses, is one of the biggest problems I see,' says This Old House general contractor Tom Silva. 'You can't depend on just the trim and the housewrap to stop water.'
That's why whenever Tom puts in a window, he makes sure to seal the perimeter of the opening with sticky sheets of self-adhering waterproof membrane, strips of metal flashing, and judicious amounts of caulk. Any rain that gets by one of these layers will be stopped by another.
Install Vinyl Window With Flange
His final step, once the opening is watertight and the window is set plumb and square, is to plug the gap between the window and the framing with foam insulation.