How good are your Google Skillz?
I’m just about ready to place an order for new double-hung window balances, for our window retrofit project. To place the order, I need to know the weight of the sash that the balance will support.
I know the existing weight of the sash (it’s about 30lbs), but I’m concerned that the new glass I buy will be heavier (or perhaps lighter?). We’ve decided to go with standard 1/8” double-strength glass (a single pane), and I’ll talk about why in a future post. The question is, how much will this glass weigh per square foot?
I found ONE sketchy reference to glass weight per square foot the other day using Google. I want a backup number to validate. Is anyone out there able to find a nice chart of glass-weight per square foot, for different glass thicknesses? I’m at a loss.
4 Comments
Derek·April 14, 2005
Can you wait until the windows are put together? How thick is the existing glass? I have some glass out in the garage I could weigh
Grex·April 14, 2005
That is a tough one. I didn’t Google but I’m wonder just how accurate you need to be. I just finished a small wooden door that is hung in a frame just like a wood sash window. It uses weights and pulleys to counter balance the door. Anyway, I had a small collection of cast iron weights. I started with two 3 pounders and they weren’t heavy enough so I went to the two 5 pounders and they worked perfect. I’m not sure what the weight of the door is but I doubt I hit it right on with 10 pounds. The door could be 8 or 12 pounds but the 10 pounds of counter weight works fine. It takes slightly more effort to close it then it does to open it but it is hardly noticeable. The door will stop at any point and stay there.
Nick·April 14, 2005
Well, I kinda need the balances before I retrofit the window (I’m betting I’ll have to cut the sash down a bit for the new balances), but the balance needs to be sized correctly for the weight of the sash. I think I’m gonna go with the weight that I measured for the existing sash, on the assumption the new glass will be similar weight. The old glass is the original wavey glass, and I think it will be comperable in weight to the new stuff.
The new balances use a spring to lift the sash, and I assume it’s important because they’ll only be adjustable within a certain range.
Good idea Derek, about just weighing some glass. I think I’ve got some in the basement; maybe tonight I’ll cut a square foot and use the kitchen scale to measure the weight myself…
Jesse·April 15, 2005
I’m glad that kitchen scale is going to good use ;)