Restoring old windows with modern balances

Question

Good afternoon. I saved a number of 1920s window sashes from my old house, and have built a new jam to use the windows in a decorative manner on an interior wall. Searching the Internet, I came across a Bob Vila YouTube video, they installed new spring balances into older weight balanced windows.

Each sash is about 8 1/2 pounds, with an average of 46" travel. The style is 2 inches wide, inch and a half thick on both sashes. I understand there's a bracket, that would be routed into the bottom of the window sash, that the spring locks into. Is this something you can help me with?

Please feel free to call me anytime. Thank you. Have a great weekend. Andrew

Tom · Accepted Answer

When it comes to old wood windows like this, we have one tried and true standby, which is our Series 500 spiral balance. My colleagues and I have been using this to repair old wood windows for years and I find it to be flexible and easy to work with.

In your case you will likely have to make room for it in the sash and jamb. The diameter of the tube is 9/16", which is a little on the thick side, but hopefully you can make that room without issue.

You'll also need the 17-012 bracket (sold separately0, which snaps to the end of the Series 500 balance and screws to the underside of the sash, cradling it on each side.

The last thing you need to do is calculate the proper length for each sash. The rule of thumb is to measure the height of the visible glass, then add 3" for the bottom sash and 1" for the top sash (assuming that your top sash even takes balances, which isn't a guarantee). So, for example, if the visible glass height of the bottom sash is 20", then you want the 23" long S500-23.

Please let me know if you had any other questions and I'd be happy to assist.