# Fixing or replacing an octagon window



## maineiak (Apr 7, 2016)

Hi
I have an octagon window with a single pane of glass. When it gets cold the glass sweats alot. I had a window company come out to see about replacing it. They told me they didn't think it was a standard size. The glass pane in it is about 17.5 inches. They said they could make me a double pane of glass and I could do the finish work from the inside as they don't do that. The outside of that window is below a standing seam metal roof. I don't think they want to do it from the outside. My question is if I was to leave that single pane there and put another single pane inside close to the inside wall so I would have about three inches between the glass. Would I have moisture between those two panes?
I live in Central Maine. 
Thanks


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## Warm_in_NH (Apr 8, 2016)

The key would be to make sure it's sealed. As long as it's sealed and no moisture can migrate into it, there should be no problem. 
That said, any pin hole leak that would let air into the space would eventually be enough to fog it out.


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## peakbagger (Apr 8, 2016)

My parents had an odd sixties contemporary with triangular single panes. It would have cost a fortune to replace with custom double panes and would have messed up difficult to replace trim. At least 20 years ago they had plexiglass inserts built that had magnetic strips on the edges. There was a self stick steel strip applied to the window frame and the window just hung off the steel strips off the magnets. They weren't sealed but rarely if ever fogged. The biggest limitation was that over the years, there was some distortion in the optics (waves) of the plastic and there was some clouding (but not noticeable to most folks). They did make difference in the amount of drafts coming off the windows on cold days. These were definitely not the equivalent of double panes as the space gap between the outer glass and the interior panel was 2 or 3 inches. Generally when the gap exceeds an inch, convective currents set up in the gap and transfer more heat. The other concern is that there really is no good clear plastic that will hold up to UV damage long term, its going to cloud up. With my parents place the windows were up under an overhang so they didn't get direct sunlight. I expect that the outer pane of glass will block some UV but expect that you will need to replace the plastic at some point due to clouding.


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## Lake Girl (Apr 8, 2016)

Even factory made dual pane fail after many years and leave you with fog between the panes.  Have you tried using a stud finder to determine what the rough opening would be and how it has been framed out?  You might be able to change it out for a dual pane that is slightly larger - Jeld-Wen 24" with dual pane.  I know this is HD Canada but should find comparable ... https://www.homedepot.ca/en/home/p....eaturing-j-channel-brickmould.1000672044.html

Menard's carries a 20" that have options on trim colours; this is one in bronze:  http://www.menards.com/main/doors-w...44436517174-c-7691.htm?tid=219069062384073198


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## Warm_in_NH (Apr 8, 2016)

I had a customer in the same situation a few years ago with some odd size octagon window that was single pane and drafty, the jambs were rotting and getting bad. I made up a simple jig, built new jambs and had the local glass company make me new double pane pieces of glass for the new jambs. Wallah, new custom windows done.  Wasn't too costly either, I believe it was less than buying them custom sized. 
You can always order custom windows, they'll make anything, all depends on how deep your pockets are.


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## maineiak (Apr 10, 2016)

Thank you everyone for all the great ideas. Lake girl , there is tounge and groove on the interior so I can't use a stud finder. I think the best solution would be to try to buy a factory window slightly smaller than the one there. Trim it out to the exact size on the exterior with that plastic wood for maintenance. Then deal with the interior. Warm_in_ NH, if I can't find the right window your option would be a good choice. I could have one custom made.
Thank you again.


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## Dobish (May 12, 2016)

take out the octagon, put in a square one that opens...


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