The retrofit method of installing replacement vinyl windows was discussed in a previous article.In this one, we will summarize the installation instructions for what is known as a complete tear-out method of installing vinyl replacement windows. This installation style, as the name indicates, involves removing the old window entirely, right back to the rough stud opening. It is a nice way of installing new vinyl windows because it maximizes the glass area and completely replaces the old window, frame and all.
Before installing the new vinyl window in the opening, hammer tow nails in on each side of the opening. This provides a temporary stop to secure the new replacement vinyl window in the opening.
Once the new vinyl window is in the opening, level the window horizontally using two or three shims, spaced 16″ apart. Once the new window is horizontally level, plumb it vertically. This is also done by shimming the replacement vinyl window on the sides. Remember that the shims should be 24″ apart.
Check the level and operation of your new window. The operating sash should show an even gap between it and the vinyl window frame all around its perimeter.
Before screwing the replacement window in place, check it for plumbness and squareness. Make sure that all locks catch properly and easily.
Fasten the vinyl replacement window into place using 2 ½” #8 screws. Screws should be driven at every shim location, but not in the bottom or sill of your new vinyl window.
If your new replacement window is operating properly, cut off the shims slightly less than flush with the window frame on the inside and outside. If foam is used, start on the interior and foam between the new vinyl window and the rough stud opening using two passes of low expansion polyurethane foam. Don’t use too much, since this could buckle the vinyl window frame. Repeat the same procedure from the outside of the new window.
If you are using fiberglass insulation, use the same methodology. Don’t overstuff the cavity. Vinyl window frames can warp or twist if over-insulated.
After the foam is dry, cut off any extra foam sticking past the surface of the vinyl window with a sharp knife. Make sure that your new replacement window is operating properly and, if so, apply caulking at the shim locations on the inside and outside.
If the new vinyl replacement window was properly measured, you will have a ¼” gap on the exterior between the vinyl window brickmould (a trim piece on attached to the exterior of the vinyl window) and the exterior finish of the house (brick, for example). You will simply need to caulk this gap.
On the inside, you are ready for trimming. If the vinyl window didn’t come supplied with a jamb extension attached, you will need to build one and butt it to your new vinyl window before installing your interior casing. The end result will be a brand new vinyl replacement window which, if properly measured and installed, will provide you with many years of low-maintenance energy-efficiency.