Expanding foam insulation


Old 07-22-03, 07:34 AM
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Unhappy Expanding foam insulation

OOPS!. Shot expanding urethane foam insulation into stud spaces between window frame and opening and now windows (double hung) are very difficult to open and close. This stuff really expands and must have pushed in on frame. Now what do I do? Should I cut it out? If so, with what. What should I have used instead? Thanks!
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Old 07-22-03, 08:22 AM
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You can cut cured, expanding foam with a razor blade or utility knife. You might try cutting some out of the middle of the foam and see if that won't release the pressure. Some foam products expand less than others.
Old 07-22-03, 08:24 AM
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Opps is right....and Lefty will be along in a while to give you double "whatfor"

Probably the easiest way to get it out is with some kind of solvent. Take some of it and drop some laquer thinner or alcohol paint thinner, ( or read the can and see what they say use for cleanup.....that is the solvent ) or something until you find what disolves it easy. then put some in a spray bottle and spray back in there to disolve it. Be REAL careful about flames and sparks as a lot of that stuff is quite flamable. Your other choice is to just dig it out with a knife or screwdriver.

What you shoulda done is use the latex foam that does not expand that much and stays soft.....the one that says "For doors and windows".....or stuck with the tried and true method of strips of fiberglass insulation stuffed in there....and even THAT you can pack too tight and get the same effect if you're not careful.
Old 07-22-03, 08:47 AM
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Most of the can foams are polyisocyanate. There is no solvent once they are cured.
Old 07-22-03, 07:45 PM
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Yeah, I'm here -- now -- "WHATFOR??"

Every window mfgr. that I know of tells you not to do that.


Use a razor knife, or even a kitchen knife, and cut it out until the windows work properly.

Like 'brickeyee' said, I know of no solvent that will help you.

After you get the foam out, use a little fiberglass insulation to fill the gap. Get a roll of "pipe wrap" and use that. You are looking at about $5.00, and it'll do 3 or 4 windows. A BALE of R-11 or R-13 is about 30 to 40 times as much as you need and would cost you $25 or $30.

For Andy or I, who replace hundreds of windows a year -- the bale wil work, and is economical. For a homeowner, looking at 2 or 3 windows -- the bale is a waste of money, UNLESS you're gonna throw the excess in your attic. (TAKE OFF THE VAPOR BARRIER FIRST!!)
Old 07-24-03, 05:25 PM
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Non expanding foam
or minimal expanding foam!!

To pack batt insulation will slow air infiltration
but not stop it. Foam sealants and/or caulking
will stop air infiltration.

That expanding foam can really do some

I had a case where a household member was
'helping out' and in place of caulking, you got it...
expanding foam.
This was a home on piers, area to be caulked
was at wall and floor junction to seal the
gap behind the molding.
Molding was removed, expanding foam used in place
of caulking....wall and flooring parted ways. BIG MESS.

Still laughing about that one.
Old 07-24-03, 10:23 PM
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Yeah, southlouisiana, THAT would be a big mess.

But when you are dealing with windows, EVERY mfgr. that I am aware of WILL void the warranty on the windows if foam is used to fill the perimeter gap. You're right, packing fiberglass (very loosely!!) in the gap will only slow the air filtration. But foam from a spray can will void the warranty!! I'm not saying that the fiberglass will do a better job -- IT WON'T. But if the foam is squirted in, the adjuster (or mfgr. rep.) has no way of knowing if the foam that was used was minimal or non-expanding, or if it the "good stuff" that swells to 3 or 5 times its initial size. Once it has cured, it all looks the same!!

Now, when some foam mfgr gets a clue and makes the non-expanding stuff BLUE, and the minimal expanding stuff GREEN or PINK (and all others have to stay a cream color), now you will have a point.
Old 07-25-03, 04:46 AM
bungalow jeff
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You can tape over narrow gaps filled with loose insulation to stop the air infiltration.
Old 07-25-03, 12:39 PM
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actually expanding foam cures to form a hard crust on the outside
( and by cutting into it you loose the sealing/ air reduction quality)
whereas nonexpanding foam stays soft.
The expanding foam I see on jobs around here is a yellowish color with a hard crust,
and the non/minimal expanding foam is white, and stays soft.

I contacted the Mayfair dealer in my area to get his thoughts on this and this is what he said.
Expanding foam does indeed void the mfg. warrenty, however
not minimal expanding foam. Because it (non/min. expanding foam) does not warp or cause bulges in the window frame.
However how are you to know wht type of material was used
to seal the window, unless the walls are unfinished?
He told me that they measure from the sill of the window to the top, in 5 inch increments to note any bulges or warped areas.
In about 80% of the cases of voided warrenties expanding foam was used. He said in his years of practice, that he had never seen non/minimal expanding foam cause a window's warrenty to be voided.
I also asked about other window mfg's warrenties and he stated that non expanding foam would not void their warrenty.He said that would hold true even with upper end window mfg.s like
Anderson and Pella.
I did not check with the other companies.

As for taping, this in conjunction with batt insulation stuffed lightly
into the gap, does help to stop the air flow. However, the tape will also loose its adhesive quality over time, and you are back at square one.
If you use this method, use tape that has a good adhesive quality, such as a Hardcast foil tape with the mastic on the back,
or Tyvek makes a tape for windows with a sticky black adhesive.
Both tapes stick to wood and vinyl or metal, whereas the regular foil tapes do not adhere well to wood.
Hardcast tape is available at a/c and electrical supply stores.

I am not trying to say one is right and one is wrong, there are new materials and new building techniques comming out every day. I spend most of my days in the field doing inspections, and a LOT of time in building supply stores and on line checking out new products.
I learn about new products in these forums also, and I have to say that you guys give me lots of food for thought and keep me asking questions!!
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