Replacing window glass w double glazing?
MarvinVA
| Posted in Energy, Heating & Insulation on
I’ve started doing the maintenance deferred (for 20? years) by the previous owner of our 100 y/o farm house. This involves replacing the
rotting wood trim and generally rehabilitating the windows.
Getting into it it’s clear this is a fairly labor intensive process, and I wondered whether it would be worth spending some money to replace all the glass with some manufactured double glazed inserts.
Based on some research, I think I’m better off keeping things as is, and having some single or double glazed strom windows made for the windows. But I thought I’d throw the question out here to see what other opinions there are. The windows are 6 over 1.
marvin
Replies
Depends on so many factors -- the value of the home, it's historic/architectural qualities, the climate, the condition of the rest of the home. And of course the budget.
It is possible, if the sashes are in good condition, to install double-glazed panes in them. A special router template is used to notch the sash and trim the muntins, and then custom-built insulated glass is installed.
You can also, of course, buy replacement windows that fit inside the existing frames, largely preserving exterior and interior trim.
But if you don't have the time/budget for these, and architectural precision isn't an issue, then storms are certainly acceptable.
In general there's no point in having the storms be double-glazed unless the existing windows are in pretty bad shape. You normally want the storm to be slightly leaky (air-wise) so that the air between the windows will be more like the dry outside air than the moist inside air.
However, if the existing windows are so bad (leakage-wise) that they'll be largely cosmetic then insulated storms might be wise.
Don't forget to replace the sash weights with spring balances and stuff the weight cavities with fiberglass.
Based on some research, I think I'm better off keeping things as is
Agree 100%, esp if you plan on living more than 25 more years or so.. Many say that the 'new' insulated glass is improved and will never fog, HA-ha and BS! Insulated glass is a vast conspiracy among mfgs and installers and code makers to keep replacing windows every 30 years or so. My biggest mistake when I built my own house was to use insulated glass - stupid!!! Long live storm windows<G>
It seems to me one of the advantages of new double (or triple if you live, say, here in Alberta, where it can get really cold) glazed new windows is that you can open them on warm days in the winter for some ventilation.
What methods are there to get some ventilation through storm windows, yet still maintain their airtightness for the cold days? We used to live in a house where the storm windows had three 1" holes in the bottom rail that you could cover with a little sort of (leaky) door that shut them off when it was cold. The small leak seemed to let the moisture out too so there was not too much condensation. Although, that moisture carries some heat with it....
Has anyone seen any other ways, other than hinging the whole storm window at the top and swinging it out and propping it with a 1 foot section of hockey stick?
Not sure I'm understanding your question. Most storm windows you can get now are triple track - two glass sashes and one sash with a screen in it. So you just put both glass sashes up and the screen down. Check out the Harvey Tru-Channels.There are weep holes in most storm windows, at the sill, to let out any moisture that gets in, but the holes are very very small - nowhere near 1 inch.
You either swing the window out at the bottom (there is special hardware available to allow you to do this in a controlled fashion), or you buy double-hung combination storms. Used to be the combo storms were really ugly, but there are some now that don't look too bad and are nearly invisible when properly matched to the windows.
I am about to start fixing my own windows and have done a bit of research. You ought to read Terry Meany's book "Working Windows" -lots of info on window rehab.
As to the question of changing the glass out - the old sash weights won't match the weight of the window with the new glass so the windows won't work properly if you just change the glass. You'd have to put in bigger weights and that could get messy.
Architecture and history aside, new storm windows can perform nearly as good as new widows and are a lot easier to install. I'd stick with what you've got and put up storms if you don't mind changing the exterior look of the house. Should be cheaper that way.
Thanks for the info, everyone.I think another thing I have to pay some attention to is ways to
improve the window seals. I came across this product, which seems
interesting http://www.greenwoodworkshop.com/pages/6/index.htm. And vinyl or foam weatherstripping on the top and bottom.
I think a better choice is the kit that includes new metal slides and spring balances. Essentially converts an old wooden window into a 60s-era style with metal slides/seals on the sides.
I think this is what Dan was talking about
http://www.pullmanmfg.com
That's the stand-alone spring balance. The retrofit kits I mentioned are different -- include rails to go on the sides of the window frame, and the spring is incorporated into the rails.
Edited 8/29/2005 11:10 pm ET by DanH
I'm not familiar with that. You got a link or picture or something?
It sounds like something I might use on some jobs.
Norm used it on one of the TOH projects way back. Then I saw a cheapie version in a Menards somewhere 2-3 years ago. Don't know a brand name or anything.But, based on a Google search, try these:
Woodstar Inc. Pinnacle Hill Road, New Hampton, New Hampshire 03256.
Caldwell Manufacturing Company, Rochester, New York, phone (716) 352-3790.
Accurate Metal Weatherstrip Co., phone 1-800 536-6043.
Thanks.
I'll have to squirrel that info away until a customer wants some windows fixed. Just have to remembver where to put it so I can remember where I put it :)
I haven't seen this product before, but it seems like it would inhibit moving the window easily. The best kind of weatherstripping I've heard of for old wood windows is the interlocking kind where there is a dado in the sides of the sash. There's also a metal ridge on the side of the window and that fits into the dado on the sash sides so the "interlock" together. The ridge also acts as sort of a verticle guide for sash movement. I'm not sure if this can be retrofitted into an existing window but it has the advantage that both pieces fit together as opposed to the link you gave which I'd imagine will cause the window to stick. Maybe that's not a big deal to you.Its worth trying on one window at least.
For weatherstripping, check out:
http://www.conservationtechnology.com
I'd vote for single glazing and storms. They're more historically accurate, insulate nearly as well, don't leak internally, and cost loads less than custom fitted double glazing in old sash.
If you do want to go with double glazing, it would be better to start over with new windows. Weatherstripping the old ones to the same standards as new would be very difficult, and the custom glazing units far more expensive.
-- J.S.
Another option is just to replace the sashes. Apparently several companies sell replacement sashes where you install new jamb liners along with the custom-built sashes, so that you get a nearly perfect fit with insulated glass and tight seals.
You could also check out Zap-Packs from Jeld -Wen. Available at HD for about 1/2 to 2/3 the cost of replacements. You leave the jamb in with existing trim and just remove the 'guts' and replace with new jambliners and sash. Try one first and then if you get it right and like them, order the rest.