The DIY amateur does foam insulation?


Old 02-09-09, 03:53 PM
Thread Starter
Join Date: Nov 2002
Location: USA
Posts: 118
The DIY amateur does foam insulation?

I am trying to upgrade the insulation in several areas of my home. Soon I will be getting thermographs to give more guidance. However, there are several areas that are clear candidates - a kneewall space where the firberglass has fallen off the ceiling and some rim joist and exposed ceiling areas in our lower level. These are not huge jobs, but they are obnoxious. Both look like very good candidates for foam insulation. Now, when I look at the various Internet sites for the foam insulation vendors, all I have to do is put on my Tyvek suit and other protection and then spray away. Most of us have a hard time using a single can of foam spray. What is real? The cost of the kits are too high for the apprentice to go practice someplace. When we see video of foam insulation being installed, it is usually an open, clear area with plenty of elbow room and visibility, and it is always done by professionals. Even in this recessionary economy it is hard to get contractors for smaller jobs. Is this one the amateur should really try?
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Old 02-10-09, 01:37 PM
Join Date: Aug 2007
Location: Virginia, USA
Posts: 226
DIY amateur does foam insulation?

I think it's do-able although I've never personally done it myself. I have two cans of the closed cell reactant and extra spray nozels. The directions are pretty clear: start, dont let up until you are ready to change the nozzel tip, use even application and dont get any on you or in you. It looks a lot like spraying a car (professional car painting) which I have also never done but seen done many times: even strokes, even strokes, even strokes. Like to know if you go for it.
Old 02-10-09, 02:09 PM
Join Date: Oct 2008
Location: New England
Posts: 9,999
Do keep us informed. I'll add myself to the list of those who have read about using it, but haven't been able to pull the trigger. I'm up north and from what I have read I should not try it during cold weather. You are correct, cost is high but may be only option for small jobs. Where ever you can install rigid it is less expensive.

The other issue with all foam products is a protective fire covering. Some of the foil faced polyisocyanurate foams may be acceptable without an additional covering. Check local codes.

good luck
Old 02-10-09, 02:43 PM
Join Date: Jan 2009
Location: Atlanta, NY
Posts: 67
Richard - Yes - PLEASE DO KEEP US INFORMED. I'm tempted to go this route myself in my cellar crawlspace, where there's old stone walls.
Old 02-16-09, 11:07 AM
Join Date: Mar 2006
Location: Wet side of Washington state.
Posts: 18,399
I have used the "small" two-part foam and for the most part I would not recommend it for a DIYer. First it is quite expensive for what you get and secondly there is most definitely a learning curve.

Once you start you cannot stop spraying for more than about 15 to 20 seconds without having to change nozzles. It takes quite a bit of getting used to how much it eventually foams up to know just how much to spray in a stud cavity to have it foam up to the edge of the stud without going way overboard. If you are going to cover the studs with drywall (required in any living space) then you need to cut off the foam that expanded beyond the stud faces and all that you cut off is basically wasted.

I will say that it is excellent for insulating oddly sized areas and behind pipes and the like. The downside is that the stuff is (I think) extremely expensive, the kit I used had two tanks each somewhat smaller than a barbecue propane tank. It foamed up about four or five feet of 2X4 stud space from floor to ceiling and maybe a little more. That kit cost about $100 if I remember correctly and I know it is quite a bit more today for the same kit.

Getting rid of the tanks is another possible problem as being pressurized tanks they are considered hazardous waste and cannot go into the regular residential garbage stream. I ended up having to cut the tanks apart with a sawzall and wiping out the goo that didn't evaporate before putting them in the garbage. Although I haven't asked, I suspect that even the household hazmat station would refuse the tanks stating they were not "household" waste but commercial and therefore would require a hazmat fee to dispose of.

I would love to have my floor insulated with spray foam but in a two-foot crawlspace the labor cost of a person lying on their back while spraying (and not being able to move very well) would be enormous not to speak of the cost of the material itself.
Old 02-17-09, 07:13 PM
Join Date: Aug 2005
Location: Missouri
Posts: 33
Last fall I used a large 2-tank foam kit and sprayed over 200 feet of rim-joist. I felt it was quite easy. The key is preparation. I actually used only 2 nozzles and it would have been 1 but I choose to take a break. In preparation I pulled the pink bats and swept out the rim-joist areas. I made a clear path around the room so I could move the ladder and immediately keep spraying. I stacked the 2 canisters and bungee-corded them to a dolly for easy moving. I didn't feel it was necessary to wear a suit although a good mask is important (long sleeves & gloves too). Do it in mild weather so you can vent the room. I would do 2 things different. I would pick an area and spray 2 - 3 joists. Let the foam set (about a minute) and examine what you did. Too much, too little not enough in the corners - whatever. Then do 2-3 more and correct any issues. By then you should be off and running. Sure you will use a couple of nozzles but it will be worth it. Second I would make a 'painters palette' to hold beneath the area being sprayed as residue will fall from the nozzle on occasions and streak the wall. Expensive - yes. Made a big difference though and yes - I would do it again.
Old 03-05-09, 07:12 AM
Join Date: Feb 2008
Location: Northwest Pa.
Posts: 16
I started collecting parts for a spray foam rig.
A used gun, the drum pumps, heated hose and controller.

I looked into the prices of foam materials, in the 55 gal.

I looked into the fire ratings, and started testing my own

I ended up re-furbing a cellulose blower I bought cheap
($75) that was missing the thru blower. They run about $800,
so is used a sears electric leaf blower instead. They are rated
at continous duty, and has worked good. i did pick up a
secodn unit when on sale($40) to keep on hand.

I then fixed up a small electric power washer, made a
nozzle out of 2" pvc pipe (heated and flattened), and
attached 2 power washer nozzles to this.

Then I (it's get's better) took a plastic 55 gal barrel,
and put in a fitting in the bottom, to feed the pump.

The cellulose mixes with the glue/water mix in flight.

It's known as "commercial wall spray" and is used
in industrial buildings where it's left esposed.
It's also used in supermarkets and other public
places for sound control as well.

Look up celbar, or k-13, but don't bother these people.
They want $40,000 to license you as an approved

Look up Spray On Insulation

You could rent your local H.D. blower, add your nozzle
and pump. Their cellulose will work just fine.

Old 04-28-09, 03:28 PM
Join Date: Apr 2009
Location: NJ
Posts: 2
digger doug

You're a genius! What did you mean by the glue/water mix? Are you adding a glue or some kind of binding agent to the water?


Old 05-01-09, 07:07 AM
Join Date: Feb 2008
Location: Northwest Pa.
Posts: 16
"You're a genius! What did you mean by the glue/water mix? Are you adding a glue or some kind of binding agent to the water?"

Well thanks for the compliment, but I aint no genius.
Heck I don't even have a college degree. But I do design
machines, tools, and products for a living.

The glue is basically P.V.A. aka elmers glue.

Yes it's mixed with water 6:1 up to 8:1, remember
that water has to come back out in the form of
evaporation in about 24 hours.

So, from what i'm told, 2" is about the max. you can blow
at one time, quietly leave the room (don't slam the door)
and come back the next day, if you want to add more.

Now this was from commercial people that spray onto steel
and concrete substrates, so I think (and am going to try)
spraying onto a wood substrate (as in the o.p.'s post)
would stick better. I also want to try putting up
chicken wire, and blowing thru it.

Old 05-01-09, 08:12 PM
Join Date: Apr 2009
Location: NJ
Posts: 2

Now this was from commercial people that spray onto steel
and concrete substrates, so I think (and am going to try)
spraying onto a wood substrate (as in the o.p.'s post)
would stick better. I also want to try putting up
chicken wire, and blowing thru it.

Do you think this would work on the underside of a residential roof deck? I have a 1964 ranch style house with a dark charcoal roof (ridge vent, 2 small gable vents, no soffit vents) approx R-38 existing fiberglass/cellulose insuation, that gets hot as hell in summer from the radiant heat. I was searching for solutions when I came across your post. What do you think?
Old 05-04-09, 11:40 AM
Join Date: Feb 2008
Location: Northwest Pa.
Posts: 16
Yes I'm sure you could get it to stick to the underside
of the roof, but you'll be changing the roofing system
into what's known as a "hot roof". There's allot of
nashing of teeth about shingle life and so forth about it.
If it's ready for a re-roof, new sheeting could be applied
over lath type strips for the ventilation requirement.

Other's here, allot more knowledgable than myself,
should weigh in on what you want to do.

If insulation proves to be the right thing to do, you
eliminate the glue, by stapling up tyvek, then
cutting a slit in the tyvek at the peek, blow in loose
cellulose from there.

Or maybe eliminate all blown insulation, and
use a foam board product on the rafter itself.

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