Should I insist on foam vs fiberglass insulation?

[denvertrout]

Getting 30 windows installed by the end of the year and talking to the sales guy, he said the installers will use fiberglass insulation and not the low expansion foam. Does it make a big enough difference in the performance of the windows to be an issue? Is it something that can be done after the fact, or would that entail a big hassle?

[Windows Dun-Rite]

Some manufactures will void the warranty if foam is used. Also if vinyl windows are being installed I would not want to chance getting any foam on any part that can be seen. I don't know of any way to remove it.

[TheWindowNerd]

Foam is a better option. It completely air seals, insulates and adds structural support.
Not really an option after the fact.
I would not try to talk someone into using if they haven't done it before. You should have a pro gun, $65 -100.
If they seal with caulk both interior and exterior as well as fiberglass your job will be just as good.

[randy]

I disagree with Anthony on this one. The proper minimal expanding foams provide an air & moisture barrier; fiberglass insulation does not. Stuffing fiberglass insulation into the cavity and caulking the interior and exterior is not "just as good". It is better than nothing, but that's about it.

[Windows on Washington]

Perhaps this disagreement can be settled with an arm wrestling match in FEB or MAR???

[denvertrout]

I would prefer you all figure it out for me today

From what i have read it seems to be an area in which those that have gone to this technique really see the benefit and those that have not yet feel the way things have been done for years is still a good way. It leaves the consumer with conflicting information and makes decision making difficult.

As a physical therapist my field is exactly the same. The new techniques are embraced by the new grads and not so much by the more established PT's.

Thanks for the great resource.

[Windows on Washington]

Foam is a very nice option. I would not want it to be the installers first go at it.

If they have used it before, than you should be fine. If a windows is caulked and sealed properly, than you should be fine as well.

I would not base my selection of a contractor on whether they use it or not.

[TheWindowNerd]

We use foam when ever possible.
We have benn using it for three years.
It is more exspensive to use, a can cost $12 to $14. I can buy a whole lot of fiberglass batt for that.
Sometimes you can not foam because there is not enough room to get the foam in, sometimes you cant"t get fiber glass in either, depends on how tight the windows are measured.

[buddy110]

Everyone has valid points. I most certainly wouldn't want someone who's never used the foam experimenting on my home. However acetone will remove fresh foam from anything. We measure or inserts pretty tight but there's still enough room for foam, especially under the sill where it acts as support. The foam will insulate a lot better than fiberglass, IMO. If the window is fairly tight and caulked properly it will be pretty air tight, however the sill pocket can still transfer cold into the home, even with a slice of FG in it.

Ask the company if the have used foam before. It's the better option, just make sure it's a non expandable foam.