Spray Foam in Attic

[Sleepy]

Anybody had an attic redone with spray foam that before just had traditional insulation? If so, was there a noticeable difference in cooling? Also, what was the ballpark cost? Our home is 2200 sqft heated/cooled. I’m considering it in the near future and wondering if it’s worth it only being in the attic.

Thanks in advance!

[muzzlebrake]

You might want to google dangers of spray foam attic insulation.
Vapors linger for long periods and can cause all sorts of health problems especially if anyone has allergy problems already.

[bakin7005]

Anybody had an attic redone with spray foam that before just had traditional insulation? If so, was there a noticeable difference in cooling? Also, what was the ballpark cost? Our home is 2200 sqft heated/cooled. I’m considering it in the near future and wondering if it’s worth it only being in the attic.

Thanks in advance!

I looked in to it recently with similar size house. I chose to do radiant barrier with adding more cellulose insulation. Cost is about $3500. Contractor said spray foam is at least double that. I cant justify it. Contractor said the spray foam makes the attic "air tight". I'm not so sure thats a good thing.

[Strummer]

I had it done about 8 years ago . My house is a old wooden farm house . It made a huge difference. I had the attic and under the house sprayed . I think I paid about 1.50 a square foot . I paid cash so they cut me a little better deal . My electric bill was cut by about 80 to a 100 a month . And my ac actually cycles firing the day . Even in these 100 degree days.

[twistedmidnite]

I can only vouch for a house already having the attic sprayed. It's $$$ up front but if you plan on keeping the house it's money well spent. Our house is 2100sf, we bounce from 65-68 degrees and our electric bill is usually around $150-175

[SaintBlaise]

I know several people that have had this done. There are several spray foam companies out there, get a few quotes and also ask about potential hazards. Importantly, you will need to have the properly sized AC unit when you have foam. This is a heat load test that an AC guy can do. They look at the size of your AC, sq footage, air intake volume, and other things. Basically, you can't have too big of an AC unit with foam. If so, the unit will kick on for a quick cycle, then turn off and not do the complete job of lowering the humidity. I'm not an AC guy, so talk to someone that has experience with foam and ACs.

[bakin7005]

I know several people that have had this done. There are several spray foam companies out there, get a few quotes and also ask about potential hazards. Importantly, you will need to have the properly sized AC unit when you have foam. This is a heat load test that an AC guy can do. They look at the size of your AC, sq footage, air intake volume, and other things. Basically, you can't have too big of an AC unit with foam. If so, the unit will kick on for a quick cycle, then turn off and not do the complete job of lowering the humidity. I'm not an AC guy, so talk to someone that has experience with foam and ACs.

You must play an AC guy on TV cause thats exactly what my "real life" AC guy told me!

[double bogey]

In our part of the country we seem to build houses with the attic exposed to the outside, and then place our ac equipment and duct in this hot area. In the north, they build with the attic sealed and insulated and part of the conditioned envelope. If you seal and insulated your attic, you will need a smaller ac system, and you must address cooling in the attic space to control humidity, or risk developing mold problems. It is best to start this process during construction, and using foam in the walls as well. Sealing the house tight also means you must provide for fresh air intake and exhaust. Down here our run of the mill ac contractors may lack experience building this way. They need to be able to run a good load calculation, and size equipment correctly. Not that I have experience designing systems for these houses, as I never have, but I have seen a few with issues, mostly high humidity from oversized ac, and inadequate ventilation. A few builders are building whole house envelopes now, and soon it will most likely be the way we build all new homes.

[Jon B]

I can only vouch for a house already having the attic sprayed. It's $$$ up front but if you plan on keeping the house it's money well spent. Our house is 2100sf, we bounce from 65-68 degrees and our electric bill is usually around $150-175

^^^Our house is a bit smaller and our highest electric bill each year is like $170. During the winter months we have sub $100 electric bills. Ours is full spray foam. Walls and attic.

[krisw]

I can only vouch for a house already having the attic sprayed. It's $$$ up front but if you plan on keeping the house it's money well spent. Our house is 2100sf, we bounce from 65-68 degrees and our electric bill is usually around $150-175

Who did y'alls? I thought about doing it to our house, but not sure right now. It has plenty of insulation for the time being.

I know several people that have had this done. There are several spray foam companies out there, get a few quotes and also ask about potential hazards. Importantly, you will need to have the properly sized AC unit when you have foam. This is a heat load test that an AC guy can do. They look at the size of your AC, sq footage, air intake volume, and other things. Basically, you can't have too big of an AC unit with foam. If so, the unit will kick on for a quick cycle, then turn off and not do the complete job of lowering the humidity. I'm not an AC guy, so talk to someone that has experience with foam and ACs.

That's what they are supposed to do anyway.

[Cookiemonster1]

My only concern is that your AC wouldn’t be properly sized as you would
Need less AC size due to spray foam.

[cashcropper]

We rebuilt a 95 year old frame house on piers and have been in in for 2 years. It has a metal roof. We put batting in the walls and open cell foam in the attic against the roof. My attic is 8-10 degrees warmer than the inside of my house right now. By sealing the attic it does trap humidity so we installed a dehumidifier and plumbed the drain up to the a/c condensate drain.Attic humidity now runs in the low 50's. We also had 2 inches of closed cell foam sprayed on the bottom of the house. Works great.

[tps7742]

I can only vouch for a house already having the attic sprayed. It's $$$ up front but if you plan on keeping the house it's money well spent. Our house is 2100sf, we bounce from 65-68 degrees and our electric bill is usually around $150-175

Same here as stated above. We have been in our house about 2.5 years, it’s approximately 3100 sq ft heated/cool space and our highest electric bill has been $187.00 and some change in the summer. We keep our thermostat on 68 degrees and live north of Lufkin. We get our electricity from a coop so I am sure in the larger communities where you pay less per kw it would be better.

[SaintBlaise]

Who did y'alls? I thought about doing it to our house, but not sure right now. It has plenty of insulation for the time being.

That's what they are supposed to do anyway.

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Maybe they are supposed to do that, but most of the contractors that were involved in our build chose to cut corners whenever they could. My wife is a numbers hawk. She made the guy that sold us our trim and doors look like an idiot when she confronted him in front of our contractor about the sq ft'age of trim. We had hundreds of extra sf that he couldn't answer for, including allowances. Most home owners would never know about those little thing, but they add up. Seems like you need to know the job that you are hiring for, so you know if it was done properly.

[SaintBlaise]

You must play an AC guy on TV cause thats exactly what my "real life" AC guy told me!

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Well, we are in a newly built foamed house and having slight AC issues. We have negative pressure in our house. So when the AC is running, it is pulling air form the outside, because there is not enough cubic feet of air entering the intake. So, we had to hire a consultant to come out for the load test. Seems like our AC system is too large and we need to increase the air capacity into the AC system. Never a cheap fix.