Opinion of Spray on Insulation

[john whittaker]

Does anyone have experience or opinions on using the "spray on" insulation instead of standard glass rolls. The kind used for wall, ceiling/joist insulation in new home construction. Not sure exactly what it's called, but the kind that is sprayed in between studs and expands to fill in the space. The over expanded portion is sliced off flush with the studs.

I've heard it is way more expensive but it seems like a very good method of insulating and worth checking out. I have never seen it first hand...only on TV.

Any words of experience???

[Jim O'Dell]

John, I don't have any first hand experience, but I understand that it is really good stuff. Spray it against the roof sheathing and it acts as the insulation and vapor barrier togerther. I don't know if they spray it into the floor joists or not. If so then it would keep from having the insulation in the way of recessed lighting. Although, there could still be heat leakage to the attic. I'm sure someone will chime in who has used it. Jim.

[Steve Ash]

John I have used two different kinds in some of the homes I have built. It of course always depends if my customer wants to spend the additional amount for this type of insulation vs. conventional method.

The other type of blown on insulation that I've used is a spray on that is like blown in insulation in an attic except that it is mixed with a wetting/sticky agent that adheres itself to the wall sheething and studs to seal up any areas, and then you put in fiberglass batts ...after the insulation has had time to dry. You don't want anyone nailing siding on at this time because it will cause it to fall off the walls.

The type that you mention in my opinion is a better choice and a bit more expensive. If I were building my own home all over again I would use the method you mention.

[Karl Laustrup]

I didn't think of it until it was too late to at least check into the stuff for my house.

I did ask the GC and he did some research about the stuff. It runs about 2-3 times the cost of regular batt insulation from what he found. It does insulate very well though. Up to around R-30 in 2x6 walls from what I understand.

Brian, from the GC raised a good point though as far as using it in the walls instead of batts. It's great that you get that much insulation, but you still have windows that are at around R-7 or 8. To me it didn't sound like the extra cost would be paid back in a reasonable time frame. This seems to be a problem with a lot of energy efficiency items. Cost is prohibitive to the average person that could benefit the most from the savings.

This is all second hand info, so I don't know the accuracy of the above, but I found it interesting.

Karl

[Andy Hoyt]

I used a spray-in polyisocyanurate foam on my barn/shop remodel two years ago. Cost a fortune to have it done but it paid itself back almost immediately in terms of saved labor and time. The balloon framing in the barn was totally haphazard in terms of the vertical members and floor joists being consistently on center and as such would have been extremely wasteful of material and consumed lots of excess labor to cut batts or rigid foam to fit tightly. Added benefit is that I didn't need a vapor barrier; it stiffened the the 100 y/o building right up; and completely eliminated air leakage. Energy consumption is far lower than anticpated.

[Ken Garlock]

Hi John, when we built I had Icynene (http://www.icynene.com/) foam sprayed in the ceiling joists, and in the walls that were not SIPs. I also had it sprayed in the wall that divided the MBR from the remainder of the house; it makes good sound proofing. It is fun to watch the application. It only takes about 5 or 10 seconds to fully expand between the studs. A helper follows along and uses a big knife like tool to cut the then solid foam even with the suds.

The advantage of Icynene is that it will not shrink away from the studs. It provides a total air seal. A good air seal is something that most people overlook, mainly since the fiberglass salesman can't provide a seal with his product. The R value is about the same as fiberglass, but it costs more. I had 6 inches of Icynene sprayed in the ceiling joists followed by another 12" of blown in fiberglass.

I don't remember a specific price per sq ft, but it seems to me that it was in the neighborhood of 2X fiberglass.

Beware of urethane foam, after several years it will shrink away from the walls thus reducing your R value. It starts out great with an R of about 8, but the that value to mitigated by the shrinkage.

[john whittaker]

Hey, thanks for the input. A couple of things that have perked my interest...

I hear it can be applied to the rafters thus insulating the attic. This helps limit the extreme temp change inside the attic making it more useful for storage. Not that I would heat/cool the attic...just that it would not get so hot in summer.

I also hear it is a better insulator AND sound barrier.

Andy brings up another feature....it stiffens up old things:rolleyes: :rolleyes: :rolleyes: :p
Not gonna go there.....

[Andy Hoyt]

John - Do not insulate the rafter bays without thinking it all the way through. Unless you don't care about replacing the roof and sheathing every few years.

The ceiling is insulated so that the attic can vent through gable louvers, soffit vents, etc.

There are work arounds to this when creating cathedral ceilinged spaces. But in a retrofit - it could get really pricey.

[john whittaker]

Good advice Andy...but this is a new construction deal. Still, thanks for the info because I hadn't thought of that. It was an idea I got from my boss:eek: . (work boss not home boss)

LOML & I are planning to build next year and he is building this year. I think he would make a good guinea pig.;)

[Jim Becker]

Best thing since sliced bread when it comes to insulation, especially the closed cell variety. It insulates with great efficiency, seals for air infiltration (reducing cost for other building components and labor), adds stiffness to the structure and doesn't degrade over time. Yes, more expensive up front, but over time...nyet! We will likely be using it in our proposed addition and I just put it under our great room floor...25'x22' room, 3" (R-19+) $1400. Not cheap, but the room has been very warm all winter long and the floor doesn't bounce as much.

[Ken Garlock]

John W. The Icynene man suggested insulating the underside of our roof when we were discussing insulation. You end up sealing the attic thus turning the attic into a part of the house, the only thing missing is the HVAC into the space. The insulator said that in some parts of the country such an attic is considered living space for tax purposes.:eek: I was told that the sealed attic is becoming popular in Florida building. I was skeptical, and went with the canonical attic insulation coverage.

Jim B. Give a look at SIPs for the insulated flooring. Just a thought....:)

[john whittaker]

Ken...thanks for the info....but your signature??? I just can't determine what is is you are trying to communicate...It's so confusing. Guess I'll just turn my back to it and ignore your signature. Hope you don't feel shunned;)

Thanks for teaching me a new word. I learn so much here.:D

[Mike Mortenson]

You paid $1400.00 to insulate a 25 x 22 room?????????? That is ridiculous for Insulation.

[Jim Becker]

You paid $1400.00 to insulate a 25 x 22 room?????????? That is ridiculous for Insulation.

That's what spray on costs, Mike. $2.50 a square foot is several times the cost of R19 batts, but I believe I got what I paid for. This was in a crawl space, so the installation wasn't quite as easy as a wall application...that was factored into the labor. And in an under floor application, it will never fall down, either...like the original insulation in the space had done years ago.

[Jim DeLaney]

One question: If you use the spray-in stuff, how would you add an outlet, switch, phone jack, TV cable, etc. later, if you decide to change the lighting or other electrical?

I'm guessing you'd have to cut a channel in the drywall, run the wiring, and then patch the drywall...

If you've pre-planned all the wiring, it'll never be a problem, but otherwise...

Just curious.

[Andy Hoyt]

That's pretty much it, Jim.

One thing though. With polyisocyanurate foam one does not need to fill the entire cavity to achieve a decent R factor. Whereas, with Icynene insulation you do fill up the entire cavity to achieve the same value. Thusly running a new cable is a tad easier in polyisocyanurate.

But that said, I'd probably first try to fish up from down below or up above before tearing into the wallboard in a big way.

[Dan Connolly]

The closed cell type was just put in last week to a house being built next door to me. The R value is 7-7.5 per inch. They left about one inch not filled in a 2X6 wall which still gives them about an R-30 wall. The air seal qualitys of this type are not approachable with fiberglass. With todays energy cost I think it will pay back quickly. In the attic they put in 2 inches of this for the air seal and will top that with 24 inches of fiberglass. The builder told me the cost was about 2 times the cost of fiberglass when the labor for both was factored in as well. If I were building I would do it in heartbeat as you only pay for insulation once. (and energy forever)

They first application covered the entire wall with about an inch, then came back across that are the next day and filled in the rest of the cavity, only really having to scrape a little overspray off the studs where the sheetrock attaches.

Another type is open cell---but thats a whole different story and not in the same ballgame

[Ken Garlock]

Ken...thanks for the info....but your signature??? I just can't determine what is is you are trying to communicate...It's so confusing. Guess I'll just turn my back to it and ignore your signature. Hope you don't feel shunned;)

Thanks for teaching me a new word. I learn so much here.:D

John the signature statement is:

Eschew - abstain from, avoid doing, something on principle.
Obfuscation - make something obscure, unclear, unnecessarily complicated.

It is just a play on words, using obscure words to warn against using obscure words. :confused:

[john whittaker]

Yes Ken...I got that from your signature. But I had to look up the meaning of obfuscation before I understood the play on words.

It was a new one on me but....in my line of work I am always complaining about engineers (I R 1) writing specification and leaving something important out...and then placing an "obscure" note somewhere in the plans and expect someone to find it. Or failing to communicate an idea properly. "Eschew obfuscation" will now enter my vocabulary when ...err discussing proper communication with colleagues. Thanks for the lesson.

Now back to the Carolina - Duke game. GO HEELS !!!

[John Daugherty]

I just got a quote to spray the band in our house. It’s about 200’ total x 16” high. The estimate was 600 dollars. I priced several DIY kits and this is less than any I could find. I am going to get the spray because the spaces are very irregular and I could never get the same tightness with fiberglass. The above grade walls are SIPS so no insulation is needed. He said they could spray what he called a “flash” coat on the ceiling in the attack to stop air leakage.The cost for the attack would be 1.00 sq/ft. He said it would be about 1” thick then go over that with fiberglass.

[Bill Lewis]

We also used the Icynene insulation in our house. This is the second time we have used it and have been really happy with it. Just a couple of things to add:

Icynene has zero outgassing, The poly foams have more to a greater degree, but will subside to zero as long as it remains undisturbed.

Icynene is the soft foam, the poly foams are the hard foams, as a result, isynene will not add any structural value to walls or floors like poly foams can.

All foam insulations are expensive, at least 2X's the cost of conventional insutation. There is a payback, both in direct energy savings, and comfort.

We had the flash coat put in the attic to seal all air leaks with chopped fiberglass over top of that. The icynene installer's recomended this application for the attic space. In fact they said you could really use only the icynene, but insulation requirements demand a specific R value.

You do not have to fill the cavity in a 2x6 wall to meet out local requirements, be we paid a little extra to do so anyway. The typical installation does not completely fill the cavity flush. You can have the wall cavitys filled completely flush, but that is a premium.

If you really needed to add an outlet to an existing icynene insulated wall, it would not be hard, as the foam is soft. A fish tape would easliy push through it.

Icycnene is for new construction or open framing only, it can not be retrofitted. There are other foams for that, but I have no experience with them.

We would definately use it again.

[Brett Baldwin]

I missed this thread but it looks as though all the basics I might have said have already been covered. I actually make polyurethane foam for these kinds of applications as well as many others. I also worked on a spray crew for a couple years so I have a good background on this. (Though I highly recommend NOT doing this sort of work in Phoenix, 115 degrees + rooftop = UGH!) The company I work for makes foam, polyurea, and acrylic coatings for all sorts of applications. If there is anything else you would like to know about this material please feel free to ask. I don't know everything about it but I'm fairly knowledgeable and I know who to ask if I don't already know.

edit: I forgot to address one point that came up earlier. One person suggested that polyurethane foam (closed-cell) would pull away from studs over years while Icynene (open-cell, also polyurethane BTW but a brand name) would not. The only reason either of these would pull away over any timeframe is poor preparation/application or a bad formula for the application. Unfortunately the industry just went through a major reformulation due to EPA banning a major component of the previous generation of foam. This only applies to the closed-cell foams however. The fallout of this is that the industry as a whole is relearning many things as the new generation of foam has different quirks than the old one. As long as you aren't asking for an unusual application for the foam, this probably won't affect you. Residential applications shouldn't see any problems. (We are developing a foam that can be sprayed and adhere to substrates as low as 24 degrees F. Normally we call for at least 50 degrees F.)

[Ken Garlock]

Hi Brett. I am the person guilty of claiming that urethane foam would shrink way from the studs. My information is 5 years old, and improvements certainly could have been made since then. The shrinkage issue was a strong consideration when I was choosing an insulation.

Learn something new every day or two.:)