building windows is fun

[Neal Clayton]

cause every one can be a custom pattern without any (well, much) extra work.

building 3 casements to replace some rotten ~102 year old originals i have upstairs,

got the parts (mostly) cut today, and started mocking up the pattern to make sure the lengths were correct. mortises aren't done so that's why it bulges out.

i started with this....

174041

then it struck me that a lot of folks had patterns like that so i could do this instead...

174042

but i hated to waste the extra little muntins i had cut already so then i figured i'd put em on the side to use em, which ended up with this...

174043


anyway, i find it fun that there's something you can build which you can change completely mid-stream and have it still work ;). since the pattern is square and symmetrical the pieces will always fit, there are probably a half dozen other nice looking arrangements you could draw out of a hat and make work with the same pre cut lengths if you sat there and stared at it long enough.

[Dean Ousterhout]

What are you going to do for glass? double pane? Argon? LowE? Where does one get such glass?

We have been thinking about putting in a large picture window.

[Neal Clayton]

i just use single panes and thick drapes ;). my house is stucco and balloon framed, so the air cavity in the wall is a pretty good insulator. cooling isn't a problem, because of the inherent coolness of the stucco itself and the tile floors downstairs. the thick drapes stop radiant cool from coming off of the glass in the winter and i find that good enough.

if it wasn't, i'd put in storms.

if you want the glass to be more efficient without storms, imo insulated glass is better than double panes. insulated is two panes wedged over a piece of clear plexi in the middle. it's tricky to cut, absent a bandsaw with a diamond blade you have to cut both panes and then use some alcohol or other accelerant to cut the plexi with fire, so that would be best left to the glass shop if you haven't done it before.

but the insulated glass won't fail and trap moisture down the road like double panes with an air gap do. you just have to adjust the depth of the rabbets to accept the thicker glass, and can glaze it like you would a single pane, so you wind up with the traditional glazed look with the benefit of some insulation on the glass.

any art glass supply shop should be able to get whatever kind of glass you want, and cut if for you if you can't cut it yourself. check with someone in the yellow pages that does stained glass work, and ask them where they buy glass from.

[fRED mCnEILL]

I would like to know more aboiut insulated glass. It seems that when I google it I get mostly double paned stuff.

Do the glass people understand the difference between insulated and double glazed.

Thanks

Fredf Mc.

[Doug Carpenter]

I made myself an out swing exterior french door a couple years ago. I had my glass guy make up insulated laminated glass panes to go in it.

[Logan William]

I would like to know more aboiut insulated glass. It seems that when I google it I get mostly double paned stuff.

Do the glass people understand the difference between insulated and double glazed.

Thanks

Fredf Mc.


The reason you're getting mostly double pane stuff is because I(along with every major manufacturer of windows and glass) will disagree with Neal's definition of insulated glass. According to the Insulated Glass Manufacturer's Alliance(IGMA) which is the largest group of IG manufacturer's in the US and one of the bodies that helps create and define certifications and standards, Insulated Glass is:

"A combination of two or more panes of glass with a hermetically sealed air space between the panes of glass, separated by a spacer. This space may or may not be filled with an inert gas, such as argon."

One can have double pane windows without having an IG unit, however the energy performance of the unit will be lower. In some climates that won't matter, however in most it will make a difference. An average double pane(not IG) window with a standard LowE coating will likely have a U value(thermal transmittance) in the range of .5 to .6, if you take that same window and use a quality IG unit(with inert gas) in place of the double panes you will likely see U values between .3 and .40 depending on other factors. Now this may not seem like a large change in because of the small values but when you consider it as a % change its a huge improvement for a very reasonable cost in almost all cases.

As far as seal failure that Neal mentioned, yes the seals(there are generally 2) can and sometimes do fail. However the vast majority of IG units being made in the US today have 20 year warranties on that exact failure and the manufacturer(of the IG, not always the same as the manufacturer of the window) will replace the IG unit if it suffers a seal failure which is commonly shown by condensation between the panes.

I would consider Neal's glazing package as a quasi double pane/laminated glass offering as generally double pane's don't have anything in between, and true laminated glass(think safety glass) is generally a PVB or SGP interlayer that is molecularly bonded to the pane(s) of glass.

[Neal Clayton]

you're right, i meant laminated glass. i build windows and get them confused, how retarded is that :confused:

google laminated glass as logan mentioned and you should turn up what i was talking about.

[Logan William]

you're right, i meant laminated glass. i build windows and get them confused, how retarded is that :confused:

Not a problem, I've seen the pics of your work and thats what I figured happened, with all the terms floating around its very easy to get them mixed up and wanted to make sure that those who aren't working with windows on a daily basis don't get confused.

[Neal Clayton]

on that topic, though, one thing to consider with these thicker glass sizes.

the tenon is a function of your cope cutter and the amount you cut for the glass rabbet.

i use a 1/2" deep profile for the cope/stick joints. on a 1 3/8" window, that means a 3/8" glass rabbet would leave a perfect 1/2" left for the tenon (1 3/8 - 3/8 - 1/2 = 1/2). if you go with thicker glass, you have to ensure you wind up with enough left for a tenon. say your double pane unit or laminated glass unit is 3/8 thick, if you add that to a 1/2" cope/stick profile and you need to leave 1/4" on the outside for the glazing putty. well 1/4 + 3/8 + 1/2 = 1 1/8". that would be an awful scrawny tenon (1/4 left over). you would probably be better to make the wood parts thicker to compensate. i would say 1 5/8 to wind up with a 1/2 tenon, at least.

[Logan William]

on that topic, though, one thing to consider with these thicker glass sizes.

the tenon is a function of your cope cutter and the amount you cut for the glass rabbet.

i use a 1/2" deep profile for the cope/stick joints. on a 1 3/8" window, that means a 3/8" glass rabbet would leave a perfect 1/2" left for the tenon (1 3/8 - 3/8 - 1/2 = 1/2). if you go with thicker glass, you have to ensure you wind up with enough left for a tenon. say your double pane unit or laminated glass unit is 3/8 thick, if you add that to a 1/2" cope/stick profile and you need to leave 1/4" on the outside for the glazing putty. well 1/4 + 3/8 + 1/2 = 1 1/8". that would be an awful scrawny tenon (1/4 left over). you would probably be better to make the wood parts thicker to compensate. i would say 1 5/8 to wind up with a 1/2 tenon, at least.

Agreed, as glass gets thicker and thicker with heavier laminated panes in IG units and triple pane IG the sash parts have to get thicker and thicker in order to keep tenons big enough and the sash stout enough to withstand the operating and windloads of large, venting units.

[Leo Graywacz]

I use to build windows. Lots of windows. Usually about 70 12 lite sash a week. Milling, assembling, cutting glass and glazing.

Let me tell you. Building windows is not fun at that level.

[Larry Edgerton]

I use to build windows. Lots of windows. Usually about 70 12 lite sash a week. Milling, assembling, cutting glass and glazing.

Let me tell you. Building windows is not fun at that level.

I'll agree with that! I ocassionally have to build sash replacements for my restoration work, and anything over about 6, and I get bored. Usually when I get hurt it is on one of these kinds of jobs where it is hard to stay focused.

[Edward P. Surowiec]

Very good info ...thanks . But can anyone tell me how to remove the upper section of a Pella double hung window?? I have a crack in the outer IG and assuming that I can buy a new IG to fit the existing window I would like to replace it.
Thanks
Ed

[Logan William]

Very good info ...thanks . But can anyone tell me how to remove the upper section of a Pella double hung window?? I have a crack in the outer IG and assuming that I can buy a new IG to fit the existing window I would like to replace it.
Thanks
Ed

Without knowing the vintage and brand(Designer, Architect etc) of your window I'm going to guess that your best option is to call the local Pella Window and Door Store and have them order a replacement upper sash for that window. The vast majority of the DH's are groove glazed, which means the upper sash is assembled around the IG unit and there isn't a good way to get the IG out without replacing the sash. They should be able to determine what vintage your product is and as long as its not extremely old get a replacement sash ordered so that it will match the rest of the windows. With a new sash ready to go the uppers could be swapped out in minutes. The link to find your local Pella Store is below, hope that helps.

Pella Store Locator (http://www.pella.com/where-to-buy/find-a-store/default.aspx)

[Neal Clayton]

yeah, from what i've seen of the wooden windows from the bigger manufactuers, they aren't really designed to be serviceable. on a traditional window maintenance is pretty simple. remove the putty, then you can remove the glass, then you can even take the sash apart into individual pieces if you need to. but glazing putty and oil paint take quite a while to cure. most of the manufacturers' construction methods seem to have been designed around trying to eliminate those time consuming steps/products.

[Neal Clayton]

first one dry fit, came out pretty well i think.

kicking my own butt for missing those two small knots on the one stile and forgetting to put them on the outside. cest la vie, they'll smooth up and look ok i guess ;).

174643

[Michael Weber]

Beautiful work Neal and a fellow Arky to boot. I built some Craftsman style true divided lite doors similar to that layout for my kitchen using QSWO and it's not an experience I really want to repeat. I have been considering building some wooden storms for my 85 year old house here in Fort Smith to replace the triple tracks. Considered replacements but don't want to lose the wavy glass that remains and the windows are generally in good condition though painted shut of course:( with broken weight ropes. I have read on restoration forums that a good original window with a good wooden storm window is as energy efficient as an insulated or double glazed unit. Do you have an opinion of that? Do you have a website showing some more of your window work?

[Neal Clayton]

i've posted quite a few pics of my doors/windows in the projects forum here, if you search for my name you'll pull em up.

an original window + a storm is absolutely as efficient as a modern multi paned window. it's essentially the same thing, by adding the storm you create an air gap that acts as an insulator. in the case of vinyl options, you could argue that the old window + storm is better, since wood is a better insulator than vinyl is.

if you care to work on the originals (up to and including adding storms) check out historichomeworks.com. that site is window specific, run by a guy who restores windows and doors for a living up in new england. has lots of tutorials, both written and video, that detail how to repair everything from common failures to full blown rot and termite destruction. you'd be amazed at what people manage to save on an old window.

edit: almost forgot, go hogs! you might see me at the sugar bowl if you're going ;).

[Logan William]

Neal: I'm going to disagree with your viewpoint that an original window + a storm is absolutely as efficient as a multi pane, I do realize that I'm unlikely to convince you however I do want to share another view with the other members who will read this.

There is a lot more that goes into today's window glazing packages then simply placing 2(or 3) panes of glass with some space in between. The biggest step performance one can make in terms of energy efficiency is going from 1 pane to 2, then the jump from 2 panes to an IG unit is still fairly steep(around 25-30% roughly). From there you add an inert gas fill to the IG unit, glass coatings and other items to further increase performance, the law of diminshing returns comes into account here as you weigh marginal benefit vs cost, but many of the items like Argon fill and LowE coatings are very worthwhile.

What I'm getting at is just because you have multiple panes of glass seperated by air it doesn't mean it performs to the same level as all modern windows. If the air space between the panes is too large, you get convection currents developing between the panes which hurts efficiency, if the gap is too small heat transfer across the airspace is fairly easy. That and a myriad of other factors go into designing the glass packages in todays windows, it seems like a fairly simple concept and on the surface it is, but once you start getting into the details of it there are a lot of different factors to consider.

An excellent(but lengthy) source of more indepth information on IG in modern windows is the PDF linked below by Cardinal Corporation. Cardinal is the largest supplier manufacturer of IG units in the country and makes the glass for a large number of the major window/door companies.

Cardinal Residential Technical Guide (http://www.cardinalcorp.com/data/pdf/residential-brochure.pdf)

[Neal Clayton]

you do have to consider the source though ;). there's more to the story than the initial cost and energy savings. maintenance is a consideration as well, and maintenance from the window manufacturers = replacement, since they're not designed to be serviceable.

http://www.ohp.parks.ca.gov/pages/1054/files/testing%20windows%20in%20cold%20climates.pdf


6. ANALYSIS AND DISCUSSION
Estimated savings for first year energy costs show little variability between upgrade options when compared to the estimated energy costs of a typical window. The cost variability of upgrade options decreases significantly when lead abatement of original sash is included. Estimated first year savings are also of very small magnitude when compared with typical windows. It is therefore not worthwhile to base upgrade decisons solely or even primarily on energy considerations. 174873

a very small percentage of energy loss from a building is through windows and doors, around 15-20%. and with the options of preventing energy loss through doors/windows considered from a cost perspective, replacements just don't add up. wooden storms versus replacements are close in initial cost, within a few pennies a year of each other in utility expenditure per window, but the wooden storms will outpace the replacements over time since the wooden storms won't fail and need complete replacement in the homeowner's lifetime, just simple paint/putty maintenance every 12-15 years, which is cheaper than replacement over a span of decades, obviously.

plus there's the aesthetic considerations. people who would buy a historic building will want original architectural details. if they are missing, that will lower the resale value of the building in question. so energy saved could very well wind up being money lost, when the owner sells the building.

put it this way, from my own experience in my own house, which is just past 102 years old, no insulation in the walls, attic floor is insulated to help heat escaping through the roof, that's it. and i have removed metal storms simply for aesthetic reasons, and rebuilt my old wooden double hungs with the only design improvement being a better seal at the check rail...

my heating bills run about 50-75 bucks a month more than they did with the painted shut originals and the aluminum storms on the upstairs rooms. so over 4 months of the year, i lose 300 dollars a year, figure 600 when i get done tossing the vinyls and storms downstairs. cooling isn't nearly as big an issue since the house is designed to remain cool in the summer on its own, the inside temperature with only ceiling fans on is 20 degrees lower than the outside temperature in the summer. in a 4000 square foot house with ~40 windows (not counting another ~50 steel casements in two sunrooms which can't be fit with storms), how much would it cost me to replace all of those and would i get my money back from the windows before i had to replace the replacements? it'd cost me 30-40 thousand to buy vinyl replacements for them all, and at 600 bucks a year it'd take me 50 years to get my money back from the replacement windows. only problem is vinyl windows are shot after 15-20 at best, and i haven't seen a wooden replacement from the window manufacturers that'll see 20 either, all of their glazing methods are much inferior to paint over putty, they'll fail and wind up rotted by 20 years as well, at best.

it just can't add up to a good deal over time, with maintenance/replacement cycles considered.

[Michael Weber]

my heating bills run about 50-75 bucks a month more than they did with the painted shut originals and the aluminum storms on the upstairs rooms. so over 4 months of the year, i lose 300 dollars a year, figure 600 when i get done tossing the vinyls and storms downstairs.

Neal, Mike here again. Am I correct to assume that you have not installed new wooden storms on the restored original windows, and that's why your heating bill is MORE?
Also another question about window construction if you don't mind. If the windows in question are well protected from moisture by a nice wide room overhang, could the putty be replaced by wood? Maybe a small bead of silicon or caulk first to seal and then the wood strips over that? The wood of course would be shaped like a right triangle to resemble glazing.

Definitely Go Hogs in the Sugar Bowl. Bobby Petrino is awesome. Not going though. Not THAT big a fan :)

[Neal Clayton]

correct, i had aluminum storms from the previous owner, but took them out, i just have the single pane double hungs now.

you could glaze them with wooden strips but i don't really see the point of doing so. it'd be more trouble to fit the strips than to glaze them with putty. and the superiority of paint over glazing putty is pretty well documented. that's why you see class action lawsuits against the window manufacturers for premature failures, while many 100+ year old windows that were puttied and painted are doing fine. all of their efforts to eliminate the time waiting for paint and putty to cure with wierdo joinery and vinyl/aluminum cladding/etc haven't built a better mousetrap yet. the old way is still the better way, because the putty is flexible so it retains the seal created when the putty bonds to the wood and the glass.

it's not difficult, tooling putty isn't rocket science. it's the consistency of play doh. you just roll it into rope like strips, put it in place, tool it til it looks nice, and you're done. any mess/mistakes on the glass can be easily cleaned up after it dries with a razor scraper.

[Trace Beard]

Neil,

I'm curious what brand of glazing you use. I've thought about using Sarco (sp) that they talk about a lot @ historichomeworks and wonder if you have tried it.

thanks

trace

[Michael Weber]

Trace, I've used Sarco on one window last spring. It's ready to paint very soon. I got some from the person that buys it in bulk and resells it to individuals. Forgot who but you probably already know if you've been investigating it. I did seem to go on and tool better than the DAP33 I used before but at my level of expertise you shouldn't hold me to that.
Neal, I hate painting(particularily cutting in like when painting glazing) and the reason I was wondering about wood glazing was because I could pre-paint it with high quality paint and just apply it and job done. It would have a nice crisp sight edge too. However, I take your point about proven methods and likely thats the way I would (will) do it.

[Neal Clayton]

i'm not nearly as skilled with a paint brush as it would require to cut in against glass/putty as a professional glazier would be ;). you can cheat with tape, that's what i do. tape off the glass a 16th shy of the putty, paint, and pull the tape while the paint is wet so that it can flow out to a consistent edge.

works just as well.

i have used sarco and imo, it does most resemble the traditional linseed oil based putties, since that's basically what it is, it just lacks the lead.

in trying to find a quicker solution i've been using an acrylic putty called glaze ease for the past year. it's basically just really high solid content acrylic caulk. it's thick enough that you you can tool it with a rubber square (barely), but dries fast like caulk does. the look isn't as clean as traditional putty since it shrinks a bit as it dries, being water based, but it does seem to hold up well so far. i have sashes 3 years in the weather glazed with it thus far, and no issues.

from my research, kinda related...

a lot of the issues with glazing stem from the fact that paint formulations have changed, and glazing putty is not often used so kinda fell by the wayside as paint formulations changed with the removal of lead. in the old days you could paint over wet putty, because both the paint and the putty used linseed oil as a solvent. it didn't matter if one or the other wasn't quite cured when the whole was finished, they'd get that way eventually. but that's not the case anymore with new oil paint formulations that form a much harder film. you have to wait for the putty to skin over or the paint won't bond to it properly, because modern enamel paint isn't as flexible (not even close) as traditional linseed oil paint was, the initial hard film modern oil paints build don't let the putty oil cure properly, if the putty isn't skinned over to start with.

so whichever you use, it is important to follow the recommendations. if you want the most viable long term solution, sarco is probably the best bet. if you want to experiment the acrylic options are quicker, but the tooling is different and they take some getting used to. whichever you use, don't try to short cut the time recommended for the putty to skin over before painting, as long as you follow the recommendations it'll work fine, and last a long time.

[Logan William]

Neal,

"you do have to consider the source though . there's more to the story than the initial cost and energy savings. maintenance is a consideration as well, and maintenance from the window manufacturers = replacement, since they're not designed to be serviceable."

Of course you have to consider the source as their business is to sell IG units, however that also means that they have a very vested interested in making those IG units to be the best performing(energy and lifespan) that they can to minimize warranty costs and also outsell the competition on a performance basis.

As far as maintenance goes once again it depends on the manufacturer/brand, yes vinyl sashes generally aren't made for maintenance, however a vast majority in the standard and higher end aluminum clad window markets are very serviceable. The modern windows are generally designed to be low(NOT no) maintenance products as the vast majority of consumers don't really expect windows to need maintenance so the required maintenance outside of cleaning is pretty slim.

IG unit failures may require replacing the entire sash, but when you consider that takes 5-10 minutes per sash vs the very labor intensive and time consuming process of reglazing its extremely quick and painless for the homeowner and by the time you consider labor cost can often be much cheaper.

"plus there's the aesthetic considerations. people who would buy a historic building will want original architectural details. if they are missing, that will lower the resale value of the building in question. so energy saved could very well wind up being money lost, when the owner sells the building."

Just because many of the common new windows found today don't match old style architectural details it doesn't mean they all don't, a very substantial amount of the product made in the plant I work in is replacement for historic renovations. We will work with the architects and historic building committees to match almost anything look/shape/size/glass etc and have a very good track record delivering product that performs and matches the required look for the project.

As to the report it appears to be a very thorough report, however the very first thing that stands out to me is on the first page.....published in 1996, which means most of the data was taken/collected from '94 to '96 likely. Between energy costs greatly outpacing inflation and the U/SHGC and air infiltration rates of modern windows making large improvements(in some cases 2x as good of U values as used in that report) the $20/unit/year savings of a pocket replacement with LowE is now likely closer to $50 if not higher.

The other item noted in the closing pages of the report:
"Storm sash in the open position were effectively windows without storms, having
greater thermal loss rates. The use of double-glazed sash would negate occupant behavior as no storm window is generally installed if the window is a replacement." IG makes a much more consistent performing product and goes back to the same token as low maintenance product, the majority of homeowners prefer fewer things to adjust/maintain/operate while still getting the bang for the buck.

My goal here was to show the other side of the coin on modern, well designed windows and how they can often perform substantially better than original ones and that its not as simple as just putting on a storm window to get performance equivalent to the name brand products today. I respect your talents and abilities in building and restoring historic replacement windows, and we both probably recognize that neither of us will change our opinions on product and I won't continue that line of discussion here. If there are questions about modern window/IG options and designs I'll be happy to do my best to answer them via PM's or a different thread to keep this one on topic.

[Trevor Walsh]

But what is the % of heat loss through the glass of a window as compared to the rest of the building envelope? According to one study I've read about vinyl DP windows, I'd have to dig it up, heat loss through windows normally accounts for 10% of the heat loss in a structure, much more is lost through roof/wall joints, doors, casings and other thermal bridges. That halfed U value for glass becomes a 5% effect on the figures above. Not really enough to offset the cost of vinyl what will need replacing in 12-20 years depending on UV exposure, damage or other factors. 200 years for wood single glazed with maintinence that you could actually build yourself?

If you have a small house the window job won't take too long and that money that might go towards windows could be spend on better weatherproofing in other areas. Talk to somebody in the weatherizing business who's not trying to sell you DP windows.

[Rich Engelhardt]

i'm not nearly as skilled with a paint brush as it would require to cut in against glass/putty as a professional glazier would be ;). you can cheat with tape, that's what i do. tape off the glass a 16th shy of the putty, paint, and pull the tape while the paint is wet so that it can flow out to a consistent edge.
When painting window glaze, the idea is to get just a very tiny bit on the glass so it seals the edge of the glazing compound against water getting under it.
When I slung a paint brush for a living, I was pretty good at doing that with a 3.5" sash brush. I could knock out windows left and right in no time at all.

That was then and now is now......

I now use the tape method..

Or..

Just rip out the old windows and install vinyl replacments :D.

[Mel Fulks]

Looks like project is going well.When you get to the glazing ,there is a premium grade putty available .Sure you can find it on line .I have not used it ,but I have found the one easily found brand to be unacceptably low quality. I'm a believer in priming prior to glazing .Glazing is difficult and slow for the amateur ,make your work last.

[Mel Fulks]

Oh. I like to bed the glass in latex caulk rather than putty. FWIW when I redid some sash for my house, I took them pre primed to a local glass company told them to bed and reglaze. When I picked them up I tapped on the glass and determined the glass had not been beded. When I brought that to the attention of the counter guy he told me employee had said " it's not necessary ,we don't do them like that" . Hit them for big discount. Specs clearly call for bedding...yet they let the workmen run the place.