Replacing Your Own Windows

Dry Run and Preparing Window Unit

Before doing any caulking or any non-reversible procedures, set the new window in the existing window opening and get a feel for how it will fit. Position the window sashes within your new window unit at the center of the window unit. Next, slide the bumper stops toward the center also so that you can see the four mounting holes on the sides of the window unit.

Caulking

Caulk along the inside of the outside stops on the jambs.

Mark the sill for the sill angle. Caulk and install the sill angle.

Insert the header piece (sometimes called an expander) on top of the window unit and caulk along the top of it. Secure header/expander with the provided screws.

Install Window

Put window in opening. Use your square to check all four corners for squareness. Tap in shims where needed to square out the window. Do not knock shims all the way in "flush." Leave about one inch sticking out, because you may need to later remove them.

Screw in the provided mounting screws at the top and bottom of each side jamb. Do not over-tighten the screws.

Move the header up until it closes any gaps between replacement window and window frame, and use the provided screws to fix the header in place.

Test Operation

Test both sashes for smooth sliding. If the sashes are tight, use the adjustment screws to adjust operation. If this still doesn't do it, you may have to knock out shims and try shims that are less thick. If the shims are fine, saw off the protruding ends with a miter saw.

Final Caulking and Stops

Caulk inside of the window. Install inside stops that you saved aside with small finish screws.