Spray Foam vs Fiberglass insulation??

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Randy
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Joined: Fri Oct 08, 2004 7:26 am
Location: Houston, TX

Re: Spray Foam vs Fiberglass insulation??

#16 Post by Randy »

I agree with Homesealed, and I don't think we're far from Ecostar on this. No one is saying that you can't get a good install without foam sealing. We're saying that foam is far superior to fiberglass.

Also, if the perimeter gap is a consistent 1/8", which is rarely seen in this part of the country, caulking my suffice. But in my experience, that is rarely the case. Since the OP originally stated that the contractor they spoke to said they use fiberglass, and fiberglass is rarely stuffed into openings that small, they too anticipate larger gaps around the window.

Skydawggy.
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Location: Northern Virginia

Re: Spray Foam vs Fiberglass insulation??

#17 Post by Skydawggy. »

You are right, we aren't too far apart on this. I just hate to see someone focus too much on whether an installer uses foam or not. To me it's like arguing the difference between a .29 and a .28 U-factor. Anybody who thinks there is going to be a difference between using foam and fiberglass on a properly measured, high quality installation has lost focus on the important componenets of what's important. For the record, we use foam on our installations but for many years used fiberglass. I can assure you the jobs in the past that were done with fiberglass are just as well done and tight as the ones we now do with foam. I'm pretty sure that if we went back and pulled the windows, we wouldn't find any black streaks in the fiberglass. The only time I have ever seen that is when we removed windows that were obviously installed by a hack.

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HomeSealed
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Location: Milwaukee, Madison, SE Wisconsin

Re: Spray Foam vs Fiberglass insulation??

#18 Post by HomeSealed »

Skydawggy wrote:Yes, having foam is as critical as selecting a window. That huge 1/8 of an inch gap around the window must be filled with closed cell foam or your windows will leak air like crazy. It won't matter whether you got a top notch install and the installer carefully caulked the windows so no air will leak. And while we are at it, don't buy any window that doesn't have foam in the frames or sashes too, because we all know that it makes no sense to have insulation in your walls but none in your windows. And don't even consider a window that uses any type of metal in the spacer. Nor should you purchase a window with a .30 U-factor when many manufacturers make them at .28. I think any manufacturer that can't get their U-factor below .30 has fallen behind the times doesn't have a commitment to producing the best window they can by using the the highest quality, most-innovative, products and manufacturing techniques. All this together adds up to huge savings[/sarcasm off]
Who exactly is this directed at? Nobody has said any of this stuff... My point was pretty clearly stated: Foam is better, but not required for a sound install. OTOH, those who don't use foam are either too cheap, or possibly set in antiquated ways. To me, these points bring up more concern about its "non-use" than the foam itself. If you would like to address that without going off on a nonsensical rant, please feel free.

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