Need to be educated some. Difference in spray insulation??

JD Seller

Well-known Member
I am adding some insulation to the walls in the upstairs of the house we moved into last year. I have torn off the old plaster and am down to the studs. I am running new wiring and have been just using fiber glass insulation with the paper backing. I staple it good and tight. Then cover the inside with a plastic right against the dry wall.

A local carpenter an I where talking at the lumber yard and he said to use spray on insulation. He said it seal the house up tighter and is way faster.

I have looked on line at the type you spray on shop roofs. I am also thinking of using it on a building that I am using a short term shop.

So here is my question: What is the difference between "high" density and "low" density foam?? Which one do you use where??

I see the smaller setups that have two tanks that are about the same as 20 lbs. propane tanks. They are not cheap but how far would they go?? The outside walls of a single room??

The next step up seems to be full 55 gallon barrels and that is about $2000 for the two you need. I do have a friend that has a spray unit that is for the barrels. He sprayed the ceiling in his shop. He does not know what product he used as he just used up what came with the used unit he bought.

I had an estimate for the shop ceiling to be sprayed. It is a 50 X 26 foot building. The quote was for $4500. I thought that seemed real high.

I really want to spray the building ceiling. There is not good way to insulate it in any other way. So If the same foam would work on the ceiling and the walls of the house I would just go ahead and buy a couple of the barrels. Then use my friend's unit to spray it all. With doing both I would be able to use up the two barrels of product.
 
You want to use the closed cell foam,(hard when set) not open cell foam( spongy). It will not absorb water. I would talk to a couple of guys that do it and see what they recommend. I had mine done by a guy from Osceola IA. He explained the differences in the weights and thicknesses to use. You could call him at 641-414-5246 and he could tell you what you want.
 
JDSeller,
My local insulator sprays walls and roofs, even pole barns.

They claim it has a greater R value, zero air leaks. I think it's water proof.

40 years ago foaming walls was popular until it was discovered that formalidhye in the foam that caused cancer. Those companies folded up and ran.

Foam will burn so it definately needs has to be covered up. No idea of cost, just know who does it. Never priced it.

The man who sprays insulation has been in business for about 40 years. It is cheaper for me to call him to blow fiberglass in attic than it is buy materials and do it myself.

He told me the best thing to do to insulate walls is buy hi density R15 fiberglass for 2x4 walls, then over with 3/4 inch celetex tuff R extruded urthane foam with aluminum on both sided. Then cover with drywall. The first house I did this way was back in 1985. It works, no issues. Have done others since. 3/4 inch + 1/2 = 1 1/4 inch which is the max you can push electrical boxes out. End produce it about R20 + you are stopping radiant heat gain and losses. I would highly recommend trying it. It took me 5 years to remodel my house. All my exterior walls are R20. It pays dividens every month on energy bill.
george
 
I asked about it for my building. It was expensive and then it seals up too tight and they said you need an air exchange unit installed.
 
Open cell - moisture moves through, lower r-value. Closed cell - air doesn't move through, usually higher r-value.

I've priced it many times and outside of specific places it works well I can't make the premium price work out. It has to be covered in a shop with grinders and sparks or it makes a great fire. Even the fire retardant formulated stuff burns.

Damp spray on cellulose seems to work out better price wise but its hard to beat good old fiberglass.
 
Use closed cell. Moisture can get through open cell.
Yes it's expensive but it not only insulates,stop air movement and moisture.
I've use it several times in my old house. Heat and air savings is unbelievable. My house was built in 1917. I removed walls in 83 and put in pink panther. In problem areas where cold and heat still made it in, closed cell foam stopped it. I sprayed it myself. Best insulating money I ever spent.
 
I would never do fiberglass in a home again, pay the extra money and do closed cell foam. There may be rebates, check on them.
 
On a recent "Hometime" show, they showed that they sprayed a thin layer of sealant over the cracks where air was likely to leak and then installed fiberglas bats over that. Apparently that is a better solution than spraying the spaces full of closed cell foam.

Just a suggestion to investigate.
 
The closed cell insulation works great until you house catches fire. The stuff is flammable and would make the house burn like a christmas tree where fiberglass wouldn't add to it.
 
Top 10 Questions Asked About Spray Foam Insulation (and their answers)
1. What’s the difference between open cell and closed cell spray foam insulation?

Answer: The raw materials of both types of foam are nearly identical. The main difference between them is how dense they are (or, how much we fluff up the material during the spraying.) The closed cell foam is the denser formulation of the material. This change in density affects its physical properties in many positive ways. However, the open cell is generally the much more affordable choice of the two. Therefore, whenever there aren’t reasons to disqualify Open Cell foam’s usage, it generally will be the product of choice.


2. When do I use open cell vs. closed cell?
Answer: The general rule to follow is that one should treat open cell foamidentically to fiberglass or cellulose. It is an excellent insulator giving the end user a near perfect fit, in doing so, it also creates a nearly perfect air seal (in contrast to fiberglass or cellulose.) This air seal is responsible for up 40% of heating and cooling savings of the house. However, closed cell foam can be used in numerous situations for which there is no other answer. It is intrinsically structural, a vapor barrier, a drainage plain, an air barrier and, of course, highest perhaps the highest R-Value per inch available on the market (usually around 7 per inch).

3. What is Icynene® insulation?
Answer: Icynene® is the manufacturer of well known a Open Cell spray foam insulation. To date, this manufacturer does not produce a Closed Cell spray foam insulation. Icynene is not a type of insulation, it is only the name of a specific manufacturer. However, many people in the building trades use the name “Icynene” and spray foam insulation (both open and closed cell) to mean the same thing. Therefore, care should be taken to clarify if the speaker (or specification writer) intends specifically Icynene brand open cell spray foam insulation or had a more generic intent in mind.


4. Can I install spray foam insulation in an unvented roof ceiling?
Answer: Yes. However, care and thought should go into determining if closed cell spray foam is necessary when mapping the potential locations for condensation in the wall cavity.

5. Can I install spray foam insulation in an unvented crawl space?
Answer: Yes. However, one should only use Closed Cell spray foam. Open cell spray foam does not deal with dampness well and is an excellent nest for rodents and others.

6. Can I install inject foam insulation into existing cavity walls or other inaccessible
spaces?
Answer: Yes. Both open cell and closed cell foam is available for injection into inaccessible spaces. The material is injected as a liquid and then rises to completely fill and insulate the void. Injection foam is a tool that few builders
know about and can be a cost effective solution to numerous retrofit problems.

7. Is the spray foam insulation flammable?
Answer: Yes. According to the International Building Code, all Foam Plastic Materials (not just spray foam, but Styrofoam, sound proofing foams, extruded polystyrene, foam boards, etc.) must be considered flammable (no matter what
any salesman tries to tell you.) Different manufacturers’ foams have different flammability. Currently, there are a number of foams that perform over and above the standards required by the International Building Code. However, the literature of each manufacturer’s foam should be reviewed before a project commences.

8. Can I install spray foam insulation directly to masonry?
Answer: Yes. Only Closed Cell Spray foam may be used directly to masonry. (Open cell foam will get and stay wet soon after installation.) A primer is generally not necessary. However, a dew point/wall condensation analysis should be completed to insure that moisture within the masonry does not free within the masonry itself and cause an untimely degradation of the wall.
Although this is a theoretical possibility, we have never witnessed it on any of our projects.


9. Can I leave spray foam insulation directly exposed to the sun?
Answer: Yes, with limitations. Spray foam left directly exposed to the sun and weather will begin to seriously degradate after about 1 year. However, after a few days, the foam will change colors and begin to yellow.


10. Is spray foam insulation waterproof?
Answer: Some spray foam insulations are waterproof. This depends on the density of the foam. However, open cell foams are definitely not waterproof or water resistant. Rather, open cell foams can hold a tremendous volume of water.
Lower density closed cell foams are water resistant, but not completely water proof. However, higher density closed cell foams can be water proof. Check with your installer or the foam manufacturer for more details.



Benjamin Marshall, LEED AP, is the Principal of Green Stamp Insulation.
 
(reply to post at 22:13:48 09/02/14)

Just a comment on the fire issue of foam insulation: When I bought this place in 2000 the lower level of the barn had been sprayed with foam insulation for a pig operation. Since the barn was infested with power post beetles I had to remove all the insulation to allow access to the wood for treatment.

Now, what to do with all the foam. Since I had a large pile of old wood I removed in the process I decided I would add the foam to the pile and burn it. The foam did not really burn in and by itself but charred from being in the fire.

I believe the term used for this type of foam is "does not support combustion". In my experience it does burn but does not go off like the Hindenburg as many would have you believe.
 
I had an inch of foam sprayed in the wall and then fiberglass batts over that. Makes a nice tight building.
a167903.jpg
 
Sheets of plywood stacked don't burn well either. I can assure you
after looking at several burned out potato storage warehouses
insulated with spray foam that it burns and produces a massive
amount of smoke. It doesn't burn like gas but it goes alright.

It needs to be covered with something in a shop with welding or
sparks just like styrofoam.
 
We use sprayed rigid polyurethane foam for new construction cold storage buildings.

Most installations include a fire proofing material to be sprayed over the foam.

The last new installation I did was about 2 yrs. ago. The product used was manufactured by: LaPolla Industries, Houston, Texas. 77032.

The "MSDS Report" concerning their product clearly states about the hazard of fire. They recommend the insulation be covered with 1/2 inch of drywall.

Hope this helps.

John,PA

I always keep an "MSDS
 
Lots of good comments below. I just want to add a few.

As you are finding out, foam is expensive. But it seals tightly and provides good insulation and a vapor barrier (high density).

Low density foam has a tendency to crack when sprayed on thick. Not a good choice. IMHO

The company I used to work for sold installation equipment for foam. One of our customers caught their garage on fire from welding sparks. They did not spray the fire proof coating over top. It was not so much the insulation burning (though it will) but the gas vapors that had attached to it that created the problem.

Code requires that you cover all foam products with a fire barrier (such as drywall).

If I were insulating a roof with spray foam I would use a high density closed cell foam over ventilation pans. This is the way I intend to do my attic room when I find the funding.

You did not say where you are. Here in my part of Virginia there is almost nobody who will spray foam. If they do they want to spray the low density stuff. In our mixed climate, vapor barriers can do more damage that good (Water condenses on the inside in the winter and on the outside in the summer).

Cliff(VA)
 
JD seller: I have read your posts for years. You are a practical guy and likes to do thing correctly.

Foam is the correct way to insulate and fiberglass is an obsolete product.

I insulate walls with low density foam.
It is a lot less money and gives you most of the benefits of foam. 99% of the moisture in walls comes from air movement and the low density foam stops air movement. Have done about 125 homes this way and remodeled some 10 years after foam and they are like new inside. I don't use a vapor retarder either.

Get a number of prices. Foam contractors are small operators and their pricing is all over the place. Find someone you trust. Foam is not that easy to make and like other things takes some skill to make and apply.

Foams R rating is actual and fiberglass is much lower than stated. The fiberglass guys rote the book on how insulation is rated and they cheat.

Also it is not just savings in heat or air conditioning costs. You will be more comfortable in a foam building. foam blocks radiant energy.

You experience it when you set your stat at 70 in the winter and you are still chilled and at 70 in the summer and you are still warm. Your body senses radiant and reacts to it. Like sitting in the sun inside.
 
JDseller, I went thru the same thing when I built my shop 40x100. Was having some serious health issues(bad farm accident), so I opted for cellulose in the ceiling and fiberglass in the walls. If I knew I was going to be alive today(ten years later), I would have used closed cell insulation.
I almost drove myself insane reading on the internet, you tube videos, talking to contractors, considering doing it myself.
If I were you, I would research it then forget about it for a little while. Do something else and then come back to it when you head clears. This is one area of construction that make you feel like information overload is paralyzing.
 
JD Seller: I just re-read your post and have changed my mind. You are not doing new construction or insulating a pole building.
You are insulating a limited area of an older house.

In this case I would insulate with fiberglass. If the wall cavity is drafty seal it up with caulking. Board splices, wire and pipe penetrations.

You should not use Kraft-back insulation and poly at the same time. Its called a double vapor barrier and is not allowed. I would choose poly so you can use regular unbacked fiberglas as it will be easier to fit than Kraft-back.

That old home is leakier than newer. Kind of like a bucket with holes. Maybe no point in closing one or two small holes tight when there are still lots of big holes left.
 
I bought two sets of the smaller containers that you described. I foamed a couple of rooms with them. It is simple but just like welding, it takes a little time to get it right. For a large area, I would pay someone to do it right. The experts can get the thickness right so that there isn't as much wasted and you are not poisoning yourself either.
SDE
 
I have a neighbor who sprays closed cell foam and had him spray a few rooms as we remodeled our old farm house. Unbelievable difference. I am having him do all the outside walls as we get to them. The house is so much more comfortable, temps are more stable from area to area. I was so happy with the house I had him spray the walls on our new pole barn shop we built this year. I did use cellulose in the ceiling though to save a bit of cash. Prices I have seen are around $1.25 per board ft, and I had 2 inches sprayed in our house and shop walls.

For an old house, I would definetly do it again. Great investment. I havent got the shop heated yet so we will see how good it works soon.

If you do it yourself study up on applying it. There are a few important things to know. Like dont spray too thick in one pass as it heats up as it cures, can cause a fire.
 

We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today.

Back
Top