Here's a picture of the area in question.

{{!gwi}}

Here is a link that might be useful:

I agree with Michael that it should be possible that the glass can be changed to tempered simply by changing out the IGU.

There are some windows that would require changing out the entire sash - but generally those are less common.

I am puzzled by the "heavier glass components" though. Michael, are you suggesting thicker glass as well?

I believe tempered glass cannot be cut to size without special equipment, which is the reason sliding glass doors which require tempered glass go up astronomically in price if you want a custom size instead of a stock size. If your windows happen to be a standard stock size for which tempered glass is available you can probably get some tempered glass at a reasonable price, if not expect to pay through the nose.

oberon,

I'm assuming the glass in those units is single strength.

Isn't all tempered double strength? The weight change may
cause the balances to be too weak to hold the sash in place.

It's a good question to ask the manufacturer. Sometimes the balance is a recoil system and I have seen two recoil balances on some tempered glass units.

Michael

Michael,

Thanks and you are correct that single strength tends to be difficult if not impossible to temper properly because it tends to cool too fast to the center of the lite when coming out of the furnace. Double strength is much less difficult to temper properly.

I didn't think about single strength in the original windows when I asked my question.

And I agree that that would be a very good question to ask the manufacturer.

Californian,

Tempered glass cannot be cut under any circumstance, special equipment or not. It must be cut to size and shape prior to tempering.

Thanks to all for the responses. I found an 84 Lumber sticker on the window sash, so I'm on my way to some answers. Thanks especially for the tip on the double strength glass. I'll let you all know if any other problems crop up.

Steve