Recently I asked Is there a way to remove condensation and clean inside a double pane window? The answer appears to be "no", at least not without resorting to very dangerous chemicals.

Two of the windows in my house with failed seals are on an unheated porch. For these windows, I don't see any reason why I need to have double panes. I don't need the insulation that the double panes provide.

I'm thinking that I could just remove one of the panes. Is it possible to safely remove one of the two panes? What technique should I use?

If I do so, should I remove the inner our outer pane?

The two windows in question are fixed windows (they don't open). They were installed when the house was built 20 years ago. They are above a sliding door, so they are fairly high off the ground. The gap between the panes appears to be about 1/2 inch.

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    I can't imagine how you'd successfully smash only one pane and clean up the edges while maintaining the thickness that held the sealed unit in place. Post a pic (detail where glass meets frame) and we could have an opinion about how hard it would be to get the entire sealed unit out, and guess at putting a replacement of some description back in. Commented Apr 20, 2016 at 15:02
  • How much separation is there between the panes, and how old is this window? The old non-sealed double-pane Windows in my kitchen actually have vent plugs that could be removed to access the space between the glass. Most modern double-pane systems, however, are both sealed and have the panes closer together, making that not an option.
    – keshlam
    Commented Apr 20, 2016 at 15:31
  • @AloysiusDefenestrate: If I was forced to do it at gunpoint, ID try a glass cutter and hope to take it out cleanly ... Or just reglaze completely, as either single or double pane; it cost me $15/sash for some windows I just had done (since I did the work of dismounting them, bringing them to a glass shop, remounting and repainting the new putty after it dried).
    – keshlam
    Commented Apr 20, 2016 at 15:35
  • I've added a picture. Would you consider breaking a pane and just pulling out all the shards with pliers? Commented Apr 20, 2016 at 15:54
  • Still think smashing is a poor choice -- especially if they're tempered (as was hinted in your other question). Try pulling away some of the trim around the sealed unit to see how it's held in place. As others have noted, sealed units can be made to exact size specs at reasonable prices. Commented Apr 21, 2016 at 0:52

5 Answers 5


I woud not try the "cut out or smash one pane" approach. I might try removing the pane as a unit (yep, you're going to have to dis-assemble wherever it was "built in place" a little) and drilling the seal/separator full of holes to ventilate it - or simply go ahead and replace it. If ventilated, the ventilation should be to the outside air in a heating climate.

If you replace it with a single pane unit you will very likely have condensation on the single pane, leading to sill rot. Even an unheated porch (which is connected to a heated house) is going to be warmer and moister than the outdoors in winter.

If the glass is tempered, you'll have crumbs, not shards, if you try to cut it or break it. It may or may not be tempered.

To borrow from my comment on the incredibly dangerous answer to your prior question, IF the panes are not tempered, you could try drilling two holes top and bottom on the outside pane, and glue screen over the holes.


I have successfully and very gingerly broken the interior side of a double pane window and removed the shards and chips with pliers and fingers--again, gingerly. The stain/fog inside had made them look unattractive and blurred the view. I hit carefully with a hammer in a lower corner, and started pulling from there. However, the inside of the outer pane--which remained--had lots of stain on it. It took a while, but with lots of rubbing, even with SOS pad plus vinegar plus kitchen soap, most came off. I had to remove the wood trim to get to it, but the frame from the window remained. I put the wood trim back, did a little careful wood dough filler, and it looks as good as new (if you don't look too closely). Cost: 0


I have similar windows at home (mine are pushing 30 years) and I've been able to replace a broken pane in one window some time back. It was not fun. As I recall, there is a rubber spacer between the panes and glass may be glued to it, and the whole assembly has the exact thickness of the channel in the window sash. If you simply remove one pane without doing anything else, the other pane will be loose. And, in order to remove it, you need to disassemble the sash and pull out the spacer, at which point you might as well wipe the interior, reassemble it as double-pane again and reseal.

I would not recommend trying to break it since you'll end up with 100 small shards partially glued to the spacer along the entire perimeter of the window.


I have done it accidentally. It is a full length window in a porch door, so the double glass is not essential. Apparently a leaf blower blew something into it and broke the outer glass ; I discovered it after cleaning the yard. As a door it is safety glass it broke into tiny pieces. When I saw the small hole I put tape on the rest of the glass so that tiny pieces did not go every where and broke all the glass out. There are still some tiny pieces of glass in the edge , they are not noticeable unless you wipe the glass with a cloth. If I was doing it deliberately , I would use a spring loaded center punch, I believe this is a way thieves brake car windows.

  • A spring-loaded punch is what I was thinking, too. Provides the "pop" to break the glass without going all the way through to the 2nd pane. I think they're also sold as car "escape tools" along with seat-belt cutters.
    – FreeMan
    Commented Jul 19, 2022 at 15:20

The glass is usually adhered very strongly to the seal. Any modifications to allow venting or convert it to single pane will cut its effective R-value down to that of a single pane window.

If you know the brand of the window, you can order a replacement pane - I paid around $85 to replace one of mine a couple years back. It's not cheap, but probably worth it in the long run.

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