V-Seal for Rattly Double-Hung Windows
The amount of air that can sneak around rattly double-hung window sashes can be decreased substantially using V-Seal weatherstripping. Double hung windows are the type that are raised and lowered by the old sash rope and pulley system, not the ones that slide in plastic channels or "balances".
What is V-Seal? V-Seal is basically a long strip of plastic folded over into a V, with one side of the V having a strong adhesive on it. The V-Seal is installed in the channel in which the window sash moves up and down, so that when the window is closed, the V expands to fill any extra space between the sash and the frame and the wind can't howl around the window sash anymore.
You can install V-Seal between the window sash and the frame on the bottom sill (where the sash presses against the bottom of the frame), the top of the window (where the upper sash presses against the top of the frame), and lower sash sides of double hung windows. Don't install between the meeting rails of the upper and lower sashes. That can make it hard to close the window well.
INSTALLATION:
1. Open the rattling sash all the way (hopefully it's just the lower sash, but you can do the upper sash if that one is really loose also).
2. Clean the inside of the window jamb with a tack cloth. If needed, you can wipe with isopropyl or rubbing alcohol, which will dry very quickly. Don't use a wet rag; the adhesive on the V-seal won't stick well to wet wood.
3. Measure the length of the channel in which you want to install the V-Seal. You only want to install it where the window sashes are when the window is closed (i.e. don't put V-Seal in the upper half of the channel that the lower sash sits in when it is open. When the window is open, you don't worry about air infiltration).
4. Then cut the V-Seal to that length.
5. Open the window sash as far as it will go. In other words, if it's the lower sash, slide the lower sash all the way up. The V-Seal should be placed so the open part of the V faces the outside of the building. This way, when the wind blows, it will press the V open wider and seal the window better.
6. Get a piece oriented correctly, then peel 2 inches or so of the adhesive at the top of the V-Seal and ease that part up between the window sash and the window channel that the sash slides in. Once it's several inches up inside that channel, continue to pull off the adhesive in the back and press the V-Seal into place as you unpeel. This makes it so the V-Seal is glued way up higher than the sash ever goes, so the sash will never catch the edge of the V-Seal and rip it out of place.
7. Press the V-Seal adhesive firmly into the channel. Keep it straight. If you have a good stapler, open the V-seal up, slide the stapler inside and staple the V-Seal in place to make extra sure it stays.
That's it.
