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How to Install a Replacement Window

Replacements for older style wood double-hung windows add performance and efficiency without removing the entire window frame.

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Step 1: Watch an Overview Video

Step 2: Remove the Old Window Sash

Replacement windows are 'made-to-order' in ¼" increments. Make sure you get precise opening and window measurements before removing the old window sash.

Many windows in older homes are painted with lead based paint; when removing old windows take proper precautions to minimize exposure to dust.

Step 3: Weather-Proof the Frame

Next, it’s a good idea to set the new unit temporarily in place to test for the window. Polyurethane sealant is then placed around the existing window frame for weather-proofing. Before installing the new unit, verify that the installation screws will fasten into solid wood. If not, provide solid filler at screw locations.

Step 4: Install the New Window

Check the new window for squareness by making sure the diagonal measurement from corner to corner is within 1/16" in both directions. The new window is installed by setting the bottom in first and tilting the top into place. Thin wedges called shims are inserted until the unit is centered and setting plumb and square.

The window is then secured in place by screwing it firmly into solid wood. After applying low pressure insulating foam between the new and old window frame as well as a high quality exterior seal your old window is just like new. If there are any problems with the operation of the new window, recheck the shim locations and adjust for plumb and square.