spray foam aroun vinly repl. windows?
I have read what I could on using spray foam to insulate around vinyl replacement windows. I am leaning against the 1/2″ insulating wrap that is optional for the windows I chose. I feel like the wrap is hard to install and could be not enough in non-square or poorly measured openings. Instead I requested that the installer use a spray foam. I even offered to supply the foam and the gun.
The installer is against spray foam and called the manufacturer who was very negative. The manufacturer’s arguments are as follows:
1. “quality” fiberglass stuffed in the gap is just as good,
2. spray foam will bow the sashes making the windows inoperable, and
3. spray foam will stain the vinyl when it oozed out.
I feel like I can discount #1. Seems like the low expanding foam (DOW or Hilti) with gun application will avoid bowing sashes. I have been unable to find any information on staining. The manufacturer said I should work with the installer on this. I might be able to convince the installer that I will take responsibility for inoperability and staining. I need to convince myself first!
My questions are as follows:
1. Has anyone seen or experienced bowing when using low expanding foam with a gun?
2. Is it possible that the foam will stain the vinyl?
Any other tips would be greatly appreciated.
Replies
My two cents,
Yes in certain situations even low expansion foam can blow out a vinyl window ,
warping the frame. If you have a gap between the wood frame and the window
wherein the drywall or other finish surface overhangs creating a small opening(i.e.
large volume-small exit path) and then over fill it with foam, it can lead to warping.
Particularly below the header where the top window flange has been left un-nailed
to allow for settling & wood shrinkage. The real key is to read and the follow
directions; fill the cavity only halfway with foam to allow for expansion. If it needs a
second pass then do it.
I've seen one to many window with a Niagra of cured foam cascading down the wall
from an excess of zeal with the foam gun.
P.S. for narrow cracks; a drinking straw cut short, creased flat, and taped to the
tip of the gun works great. Micky D's work better; larger heavier straw.
Some of the foams are solvent based and will do a real number on the plastic. You probably need a latex based foam.
I think you are making a mistake, I always follow the window manufactor guidelines. If you use foam, and have window problems, they will walk away from the problem for failure to follow instalation guidelines.
In my house I bought vinyl replacements, and have had no problem with the fibreglass insulation. Makes me wonder about the science that says how bad fibreglass is.
I'd use the foam.
It's advantages (many and compelling) are more than worth the risk (few and overblown).
I worked around windows (mostly for dealers) since 1998 and all the windows we installed were foamed in place. Never had a serious problem w/ windows -- although i have seen an overfoamed vinyl patio door or two.
If it gets overfoamed, just dig out the foam, until the frame is straight. Admittedly a bit of a time consuming task, but once done the window or door is still good. Sometimes simply putting a screw through the frame and tightening the screw is enough to striaghten things out.
TIP: If you've got a largish cavity, foam in layers. Lightly misting the cavity with water before foaming and the same after applying each layer will make it go faster. Nearly all single component foams are moisture cure (that's why they stick so well to your skin!! - we're always sweating ....even when we don't look like it)
Stephen, you are missing the point. The manufactoror said not to. I also have had good luck with foaming around winows, but would not if the man. said not to!
A manufacturer of good quality vinyl windows would not likely say there would be a problem. Sounds like the guy you talked to was unsure of himself ... maybe you got the wrong rep that doesn't really know or understand. You getting reasonable quality windows?
Non expanding foam should be just that. NON EXPANDING.
I got foam on my frames ... scraped it off/cleaned it up ... no problem. Besides, by and large ... there should be very little foam getting on the finished surfaces at all ... trim w/ drywall and/or casing and it should hide minor imperfections of foaming.
Just my 2 cents. I've tried foam a few times and always have problems with it oozing. Not from over use but from it finding a crack somewhere. I find it hard to believe that anyone can tell the difference in a window foam insulated and one that is correctly fiberglass insulated. Does fiberglass take longer...yes but not longer than cleaning foam off your brand new window.
Chuck
"Non expanding foam"oxymoron alert..
.
A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
I never heard of "non expanding" foam, only "low expanding foam"
ALL foam expands some, If you want no expansion, you use caulk!
You're right ... I stand corrected. Duh ... had a brain f__t there.
Yes I've seen it bow windows, (my own)
I still use the foam on the replacements...it depends on the foam and how you apply it. A little dab'll do ya.
If they say no then it's your choice. Foam is the superior product by far. It gets all the air passages.
Make spacer sticks and put them on the ID vertical and horizontal. Never had a problem after that.
I got nothing against packing in the fiberglass, really. It does a good job if you really pack it in. A lot of people bad mouth it, but it works ... if you are at all nervous or simply don't care for the foam option, it's a good way to get rid of some scrap fiberglass. Good sound characteristics, too. Many say don't pack it in ... lose the R-value ... which is a bunch of BS ... FILLING (the key word here) a 6" cavity with too much fiberglass will give you a lot more R than 19 or 21.
You can bow the frames packing with fiberglass too.
It is an ironic habit of human beings to run faster when we have lost our way. --Rollo May
Yeah, if you really over do anything ... you can do it wrong.
But if you pack fiberglass really tightly, aren't you left with glass, which has a very poor R-value? My understanding was that the R-value from fiberglass was in the air, that if you squish it - it's of very little value at all.
I don't understand the science behind it, but according to what I have read, he is correct.
If you pack it that tight, you've gone WAY to far. I doubt that anyone could go that far. Pack it very firmly, don't over work it. Rigid fiberglass is 'packed' pretty tight w/ R-values much higher than batts. It's a matter of balance of all glass vs. all air ... LOTS of little air spaces is much better than a few large ones ... that's why high density foams (e.g. extruded vs. expanded polystyrene) work better than the low density type.
>>>Any other tips would be greatly appreciated.
We've got vinyl and wood/vinyl windows. I foamed around all of them and all my exterior doors without issues, but I didn't use a gun, just some cans of low-expansion foam.
Scott.
Always remember those first immortal words that Adam said to Eve, “You’d better stand back, I don’t know how big this thing’s going to get.â€
Not a good idea. Too late now, does everything work?
Absolutely. No issues at all, on doors or windows.Mind you, I'm aware of the pressure issue, and was careful to add a bit of foam, let it expand, add a bit more, let it expand....repeat as necessary, let dry, trim.Scott.Always remember those first immortal words that Adam said to Eve, “You’d better stand back, I don’t know how big this thing’s going to get.â€
Here in my part of Canada we can get a "window & door" foam. It doesn't get hard when it sets. It stays rubbery. I've broken wooden returns with the reregular stuff. BUT as someone said: "If the manufacturer doesn't recommend it, don't do it."
Amen on the "window and door" foam. It's a huge step in the right direction over the regular gap filler stuff. What I do with vinyl windows in 2x6 and thicker walls (2x6 with a inch-and-a-half foam wrap outside usually) is run a bead of window and door foam up against the back of the cavity - right against the exterior as deep as the little straw will let me go. That seals all the gaps and it can expand as much as it wants to. Then once it's partly cured I'll come back and fill what gap remains to the wall surface with 'glas. Then tuck-tape the jamb extension to the vapor barrier plastic (this is Canada after all and we do put in miles of poly) or to the drywall if the 'rock hangers chewed the poly to bits with their little roto-zip.Is this overkill? I dunno. I had an inpsector for a while who required it and it's grown on me and I haven't been convinced to quit doing it yet. JT
I'v used low expansion foam around all of my Andersen wood/vinyl clad windows but I'v always fastened wood support strapped to the frames & cripples / headers. Never had any problems. I do know people who did'nt uses strapping & end up making saw cut in the foam to free up the double hung Andersen windows.
I've done it to mine. No problems just be careful.
http://www.youtube.com/watch?v=x-64CaD8GXw
I'm on the don't do it side unless you don't mind voiding the warranty.
I pulled all my windows out on a house. I installed a quality vinyl window. There was a 1/2" gap or 3/8" to fill. I decided I'd go the extra mile and use the overpriced foam.
Thankfully it was winter. When I was done, I could still feel the cold wind blowing. I tried adding more of this "miracle" foam. Nothing helped. Eventually, I chopped it all out and tucked in the proper amount of fiberglass. The results: no cold drafts, no leaks, a much warmer installation.
I also remember a builder calling me back because the windows I installed were bowed in. Of course, they were all foamed. The Brick layers all laid their bricks tight. The builder tells me it's all my fault and I did everything wrong. The sticker was still on the window. Togehter we read the installation manual. In plain English it says "do not use foam!" on the outside it says " leave a minimum 3/16" gap between all masonry products and the window brickmolds and sills." They have pictures showing the gaps. They have pictures with a giant X over the foam.
When we are all done talking, he still tells me I'm wrong and he was right for foaming. And he didn't think the bricklayer is wrong becuase the builder thinks it's better if things fit tight.
So, my question to you is: are you that builder? Are you going to disregard the installer who knows 100 more times than you? Are you going to disregard the manufacturers who know 1000 more times than you?
Go ahead, lead the orchestra even though you can't read music. Go to home depot and listen to the guy with the orange vest tell you how great the foam is...he probably hasn't foamed anything in his life.
Bob's next test date: 12/10/07
I get the warranty issues completely. And I'm strictly a weekend warrior who did a lot of air sealing at my place.
But I have a hard time buying that foam failed on your own install unless it didn't actually fill the gaps. I've used the window and door version of Great Stuff both in a straw can and run through a gun. My biggest problem was the occasional dud can that wouldn't squirt.
The stuff stays plenty squishy after curing, unlike the regular poly foam products. And it's tenaciously sticky, though I don't know how well it sticks to cured product for the case where you go back and add more. No bowing issues on the 3 windows and 4 doors where I used it.
I kinda see the warranty caveats as liability proofing for the manufacturer against the doofus who comes along and shoots the regular, high-expanding, hard-curing version of the foam around the doors/windows.
And I've pulled out/back plenty of fiberglass that was jet black from all the stuff it'd trapped as the air moved through over the years.
Anyway, the tone of the responses just seems contrary to the trend toward higher-performance building envelopes via SIPs, air sealing, etc.
Mr sludge, wy ask our opinion when all you seem to want is an argument. Do as the manufactoror tells you and go on with your life!
Not sure what I said that indicated I wanted to start an argument/flame war/whatever.
With as many different folks from as many different backgrounds and experiences that participate here, I think it's safe to say there'll be a range of responses on any subject.
What Jim posted didn't jibe with my (admittedly limited) experience, so I asked whether that was the case for the broader group.
I have seen the foam used for years in new construction. My personal experience has not been good.
Saying that, I couldn't understand why you wouldn't do what the manufactoror recommends.
All: thanks for the responses and advice. I wanted to follow up and let everyone know what I ended up doing. First I called the manufacturer and asked to speak with an engineer. I mentioned using foam and he started to say no. When I mentioned using low expanding foam, he completely changed his tune and said it would be no problem. He only mentioned not using foam on the bottom. for the bottom he recommended the thin fiberglass insulation used for wrapping pipes. Then I ended up buying a Hilti gun and a couple cans of Hilti door and window foam. This may be a mistake since the Hilti stuff is expensive and now I am "stuck" with the gun. I am hoping there is some advantage to Hilti. If I did it again, I would try harder to find a local place that carries the Great Stuff gun (our HD and Lowes did not). With this said, the Hilti gun was very nice and I did not need more than 1 can. As the installer installed windows, I followed him around and did my thing with the foam. There was no problem with window operation. I am glad I did this. The installer was just going to caulk along the windows after re-installing trim. This would leave a clear air-leak path on the other side of the trim. I feel like foaming the window in was the right way to go. Thanks again everyone!
I'm not positive about the Hilti guns, but I've been under the impression that they all have the same mounting thread, so you should be able to use any of the brands of foam. I've used Great Stuff, Dow Enerfoam (both Dow, I believe) and Handyfoam cans on my Great stuff gun.
Don
Thanks Don, late last night I started seeing that the guns and foams are for the most part interchangeable. The Hilti dealer (obviously) had told me that this was not the case. Anyway, this makes me feel better about my expensive Hilti Gun. I wonder if there is a difference between all these foams ... M<
Biggest difference between them that I've seen is that the Great Stuff window & door stays pretty soft after curing, the others I've tried all set up pretty stiff (whether they were window & door (low expansion pressure) or regular.
Color is the other big difference. Great Stuff window & door is a fairly bright yellow, their standard is an orange-red color. Dow Enerfoam is an off-white to ever so slightly yellowish, and the Handy Foam is a light gray. I'm not crazy about the orange or bright yellow in a spot that might end up exposed, but I've been able to cover both with stain or paint.
I've used some of them in fairly cold weather - probably down to 20 degrees or so - but at lower temps you don't get a very fine-grain foam. The bubbles end up large & non-uniform. If I'm going to use it in temps under about 60, I try to at least start with the can & gun warm.
Don
It's your call. Personally, I put no stock in manufacturer's warranties on this kind of thing. I think if you did everything right, they would still find something that you didn't do to the letter of the law and deny your claim.
They will try, so why make there job easy for them?