question about spray foam insulation

[SHANE704]

I am getting ready to build a house and have been trying to get all the details nailed down before i jump head first into this.

A local contractor told me he has been having problems with houses he has built, that had been done completely with spray foam...he said it works too well! So well that it is not letting the house breath and he is having moisture problems.

That being said, his advice to me was to spray foam the underside of my roof decking and use standard fiberglass insulation in the walls.

Can any of yall give me any advice on this?

[blgros1]

[landscaper]

PM mlj300. He just built and I think he used some spray foam.

There are two different types, I think (I'm no expert). One is a closed cell foam and the other is an open cell foam. I think the closed cell doesn't breath and the open does. Supposedly you should have both, and have them sprayed in the appropriate places so everything works right and you don't create rain in your attic and wall spaces. I looked at doing it in mine and couldn't find anyone locally who could spray both. Apparently there is different equipment requirements for each.

All that being said, mlj300's guy told him that none of that is true, and not to expect any problems.

[MudHog]

Encapsulation is what it is called. New style of residential construction where the home is completely sealed.

[Ster]

I just completed building a new home and there are two things that we did concerning this issue.

We placed a Waterfurnace geothermal system and spray foamed the entire house. The energy results were incredible. We went from a 2100 square foot home to a 5100 square foot home and saw our electricity bill increase about $50.00 as a result of the Geothermal and spray foam.

Our engineer did state that the problem with Spray foam is that it completely seals the home and prevents the home from "breathing". The result is moisture accumulating from beneath the crawlspace and unable to escape. The solution was to place a dehumidifier system within the crawlspace and we have seen no complications from that.

[SHANE704]

im trying to keep the cost down as best as possible...i was hoping that the spray foam in the attic would help with the effeciency and that the fiberglass in the walls would allow some breathing...I guess im looking for a happy medium but didnt know if this would be waste of money to not spray foam the entire house or not

[kwacksmacker86]

Holler at my dad he sprays foam insulation. His number is 6012016114 his name is john and I promise he will shoot you straight. Airtight insulation of mississippi.

[QUACKERS]

Not spray foam but I went with this and had very low energy bill

http://yourinsulationsolution.com/

[WeBeJeepin]

If I were building a new house I would spray foam it for sure. More insulation, less noise, no space in the studs for rodents to crawl in and die. Just make sure to size your HVAC accordingly.

[ms_deer_hunter]

We built our home in 2006 , we used 2-3 inches of closed cell foam in the walls , and 6 inches of open cell foam in the ceiling joist , ( i reccommend this over the underside of the roof ) as it doesnt allow the heating cooling to escape into the attic)

It will cost more on the front end but will save you lots of $$$$ on your utilities.

I have 3300 heated and have 1 (4) ton 18 seer unit on my house , keeps us cool in summer and warm in winter ,


Foam is the way to go !

go look at www.ncfoam.com

[Gene]

Spray foam has worked well for us. Most important is to coordinate this with high quality hvac system. Need fresh air intakes. You won't have moisture problems if you have high quality hvac. Combine the two for best results.

Gene