Materials needed: Vinyl Foam Weatherseal and Hex Head Screws.
Measure the width and length between the rough opening. Note: Measuring the outer frame of an existing storm window or the exterior window will result in incorrect sizing.
1. Make certain the mounting surface the storm window is to be placed over is correctly sized and constructed. The surface that the storm window is to rest against should be flat, level, and free of any debris. Cover/seal any cracks or holes that may allow for air leakage.
2. Apply a suitable low density foam tape (Vinyl Foam Weatherseal) to the back side of the storm window mounting flange. Failure to seal between the mounting surface and the storm window may cause condensation problems.
3. Place the storm window in the opening. Center the window and install one Hex Head Screw in the frame sill. Level (horizontal) the frame sill and place one screw in the frame head (See Figure 1). Check plumb (vertical) and square (90° corners). The sill of the window should be level within 1/8" across its width. The squareness of the window should be checked with diagonal measurements (See Figure 2). The difference between 1 to 4 and 2 to 3 should not exceed 3/8". Install the remaining screws starting with the sill, then the head and the sides last. Note: Do not over drive the screws; to do so will unduly deform the window frame and compromise the seal.
4. Once the storm window is installed, operate the sash by pushing the (2) spring-loaded slide bolts located on the operable sash towards each other and sliding the sash open. If the sash does not slide smoothly within its window track, check frame to insure it is square and remove screws and re-align window frame if applicable. This should correct the problem.
Note: It is possible to install the storm window "upside down" and or "inside out" which will cause the window to operate incorrectly.