# Spray foam insulation



## troyce1 (Oct 9, 2008)

We were going to install batt insulation ourselves, but got some prices for spray foam insulation as well in our third floor, which has vaulted cathedral ceilings. The cost of the batts would be about 700, the spray icynene foam is going to be about 1800. 

The installer would spray a 3 inch layer which would envelope the entire roof and the walls on eht 3rd floor. I know a majority of heat loss goes through the roof, I'm just trying to figure out the cost/benefit savings as well as increased comfort level.

Anyone have experience doing spray foam, or should we just put in batts ourselves?

I've read alot about the spray foam and everything seems to tout its benefits, no needed ventilation in roofs, much better air barrier, etc.

Thoughts?


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## Knucklez (Oct 21, 2007)

when price comparing you must also consider the R-value of the $700 worth of batts vs. R-value of 1800$ worth of spray foam. 

if it is the same or close, i'd just batt it myself because it is an attic. doesn't need to be pretty, doesn't need to hold moisture (like basement walls) if its a tiny bit more drafty, who cares its an attic with attic fans anyway.

my $0.02

Knucklez


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## PerpetuallyRepairing (Apr 7, 2008)

Spray foam has a lot of advantages for spraying under roof decks in cathedral ceilings. Go to buildingscience.com for info on it. Go to the dept of energy website for recommended insulation R value in your area.

Not sure where you live but it got quite pricey for me because I wanted to do R50 to prevent ice dams.


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## MackofCheez (Jan 26, 2009)

*Why Not Flash and Batt?*

Why not consider an inch or 2 of DIY closed cell spray foam and then putting in the fiberglass to build up to the r-value you want? That gets you all the benefits and probably saves a little money too. What's best is the spray foam seals out air, which will make the fiberglass insulation work alot better. According to www.sprayfoamdirect.com, no amount of fiberglass will ever seal out those air leaks.


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## PerpetuallyRepairing (Apr 7, 2008)

If you are in part of the country where you spend more time heating than cooling, spraying closed cell on the roof deck will put a vapor barrier on the cold side. Fiberglass doesn't act as a vapor barrier so you could get condensation on the inside surface of the spray foam. People do this but I wouldn't trust it until I saw some research saying you won't get into a condensing situation. Perhaps it would work with open cell as open cell is an air barrier but not a vapor barrier


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## jaros bros. (Jan 16, 2009)

There's nothing wrong with a vapor barrier on the cold side. You are allowed to do this, in warm or cold climates. What most people don't do is include enough insulation to get the wall assembly below the dewpoint on the exterior.

Josh Jaros


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## spraytight (Sep 10, 2009)

I think you might be able to get the sprayfoam job done for less then 1800. Submit a request for quote online and I'll get back to you in person: Sprayfoam Insulation.


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## FrancisABoyd (Mar 11, 2011)

We went with spray foam insulation too and saved some cash doing it ourselves.


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## jcrack_corn (Jun 21, 2008)

I strongly suggest the spray foam for cathedral ceilings. The cost is equivocal, here's why:

1.) The 3 inch quote is good, that is standard (minimum 3" gauranteed) - you get r-7 per inch so you will get at least r-21 (equal to a little more than the 2x6 batt insulation at r-19, which is not enough).

2.) They ALWAYS spray about 5-6 inches because it is easy and cheap for them to overspray rather than have to go back because of poorly filled areas...you will get r-28-42 probably in over 50% percent of the area.

3.) It is a disaster to fight with putting batts up in a cathedral ceiling, whether you do it yourself or pay someone. --- It will take a LOT longer to do the batts, at least two-3 times as long.....so major labor savings or your time cost.

4.) finally, just because it is the standard in good construction/practices now to use spray foam because most rafters are framed using 2x6's and you simply cant get the r-value in there (you can cut rigid foam but that is a labor intensive process also). 

You will probably save halve of the 1100 dollar difference in labor/your time alone, and the rest over the next couple of years in increased efficiency (and comfort).

(i have no ties to the industry btw, it is simply a product that delivers and i believe you get what you pay for in this case).

When you see how messy and what a temporary environmental disaster it is putting the stuff in, you will think the price is well worth it.


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## jcrack_corn (Jun 21, 2008)

CRAP.

didnt see someone Necroposted. thanks dude. wtf.


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## tbeck3579 (Dec 9, 2014)

The link posted for Foam it Green looks fascinating. I'm wondering if anyone knows anything about chemical composition of spray foam and if this product will stand the test of time and do what the company says it will do. 

I guess my biggest concern about it being a DIY project at this point is the mess. That stuff that comes in a can is sticky and difficult to clean up. The acetone doesn't work unless it is a metal tool. If it is remotely permeable, like fabric or your skin, good luck getting it off. It might be worth trying, a couple hundred bucks worth? I would hate to buy enough for entire attic and then find it isn't what I thought. :bangin:

The person who initially posted this link seemed to like it. Wonder if they are still around and willing to share the good, bad, and ugly.


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## md2lgyk (Jan 6, 2009)

We looked into spray foam when building our log house four years ago. Turned out to be prohibitively expensive because of the amount to be done (12/12 pitch ceiling throughout) and the required R value here. Even though we built the house ourselves, we didn't want to to DIY the insulation no matter what we chose. Ended up subbing it out the job to an insulating company for less than the materials alone would've cost us. And the entire job was done in less than 2 days.


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## tbeck3579 (Dec 9, 2014)

Yes it is expensive, and I have a 10/12 pitch -- though I love the 12/12 -- maybe not to work on, but the look it gives a home is awesome. The 10/12 is too much to work on, but I digress.

The reason I'm considering it is because the fiberglass has a relatively short life span -- at least it really didn't stand the test of time in my attic. We put a little spray foam around a few things 25 years ago and it "took a licking and kept on ticking"  No one seems to address the fluffy going flat -- the settling that occurs over 25 years. They don't seem to address things like the house sitting empty with no heat while on vacation (hopefully someplace warm every January), or critters getting in the attic while I'm gone (a racoon ripped pieces of my home off and took up residence while I was gone) and what all that does to the fluffy stuff. It renders the R value useless -- should have kept my money in my pocket. We haven't had any water leaks in the roof, but if the roof had leaked the fluffy stuff is ruined. BTW, the only reason we haven't had a leak in the roof is because the shingles grandpa put on 60 years ago are still protecting it! The shingles we put over his shingles 25 years ago are all but gone -- a big joke, but I digress again  Anyway, I hear what you're saying about price because I've toiled over the cost/benefit -- ouch on the initial investment.

I expect to spend the next 25+ years here; my old age years, the "can't do extremely physical home maintenance" and "fixed income" years. If I were planning to move I wouldn't even consider it. I would throw a few more batts up there and be done with it.


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