Foam insulation for walls

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nobbie48

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Somewhere I recall seeing walls in old houses being foam insulated by hole sawing an entry point at the bottom of the exterior walls and a overflow at the top. Has anyone any idea of what is used or if there are any problems? Costs?

Or could loose fill be pumped in?

Job is in Hamilton.
 
I’ve only seen holes be made at the top near the ceiling, and granular fill pumped in under air pressure. Works if you don’t have fire stops between the framing. Otherwise more holes so you can fill each pocket.
 
I've seen cellulose blown in through holes into each cavity (holes at the top, blow until it's full then move over a cavity). I haven't seen foam retrofit. Maybe it happens but I think it would be harder to get it to fill and would be more likely to ripple the wall. As was discussed on another thread, get advice from someone that knows what they are doing or you could make a disaster. You don't want water condensing in the wrong spot in the wall.
 
jc100 said:
Have you seen this? https://www.canadiantire.ca/en/pdp/froth-pak-200-foam-sealant-kit-0642657p.html

I came across it the other day. Looks interesting!
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I used a similar product in the garage...but you need to remove the drywall to the bare wall for it. Won’t work otherwise.

I think @nobbie48 is speaking about blown in cellulose insulation as that doesn’t require drywall removal...just access ports.

EDIT: this stuff

For foam insulation through holes you’d need a nozzle long enough to get to the top/bottom and spray as you pull it out. Foam insulation expands near point of contact with surface....it’ll clog up fast.
 
mimico_polak said:
I used a similar product in the garage...but you need to remove the drywall to the bare wall for it. Won’t work otherwise.

I think @nobbie48 is speaking about blown in cellulose insulation as that doesn’t require drywall removal...just access ports.
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You can do foam too but I think it has to be a certain type so it doesn’t buckle the wall with too much expansion. Years ago I looked at it to do some exterior walls without removing the siding.
 
jc100 said:
You can do foam too but I think it has to be a certain type so it doesn’t buckle the wall with too much expansion. Years ago I looked at it to do some exterior walls without removing the siding.
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Ok...learn something new everyday then.
 
jc100 said:
Here you go... Can You Use Expanding Foam in Cavity Walls?
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There is a lot of garbage in that article. Spray foam will probably make noise through the wall worse, they bring up a few times that it makes it better. They argue spray foam makes it air tight, with open cell foam, you need more than 3 inches and you only have a 1" gap so that is crap. Protects from moisture is crap, you ruined the drainage plane.

I'm not saying it can't be done, but I trust nothing in that article.
 
For double-brick or frame walls

Retrofit wall insulation brand is called “air krete”

Taken from a flyer I got in the mail

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Clarifying this is a wood frame wall, second floor. It's a re-siding job that could turn into a money pit. A big part is to add some sound insulation.

The house is 90+ years old and the upper level was probable planked over the studs on the outside and then shingled. I suspect any insulation that might have been in the walls has settled. I don't know what they used back then.

The planks, even if tightly fitted originally, have probably shrunk so a layer of OSB will go over them. The work could happen from the outside if it didn't cause conflict between trades.

Back in the days of UFFI someone I know got a grant to do their solid masonry walls with the stuff and got another grant to have it removed or neutralized. It never should have been done in the first place.
 
nobbie48 said:
Clarifying this is a wood frame wall, second floor. It's a re-siding job that could turn into a money pit. A big part is to add some sound insulation.

The house is 90+ years old and the upper level was probable planked over the studs on the outside and then shingled. I suspect any insulation that might have been in the walls has settled. I don't know what they used back then.

The planks, even if tightly fitted originally, have probably shrunk so a layer of OSB will go over them. The work could happen from the outside if it didn't cause conflict between trades.

Back in the days of UFFI someone I know got a grant to do their solid masonry walls with the stuff and got another grant to have it removed or neutralized. It never should have been done in the first place.
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Some of the old stuff years ago kept off gassing some noxious fumes. Some of the chemicals can be sensitizers which means your symptoms get worse rather than better over time and you react to lower concentrations. I don’t think those formulae are used any more though but I could be wrong. I see lots of ads on the city limits here about “green” and “enviro” spray/injected foam.
 
If the sole purpose for this is acoustic attenuation between the walls, i would recommend just removing 1 layer of plaster on the walls and setting acoustic patterns insulation blankets (3"-4" thick), reapply the drywall and whatnot. If it's a wet wall/has plumbing in it, recommend this instead of just blowing in any material, to avoid moisture issues in the near future or seeing what may already be damaged.

Loose fill insulation would be a cost effective solution for acoustic, spray foam insulation (closed more than opened cell) is more for thermal properties than acoustic.

Edit: also assuming these are all interior partitions and not exterior walls.

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Mango Rider said:
If the sole purpose for this is acoustic attenuation between the walls, i would recommend just removing 1 layer of plaster on the walls and setting acoustic patterns insulation blankets (3"-4" thick), reapply the drywall and whatnot. If it's a wet wall/has plumbing in it, recommend this instead of just blowing in any material, to avoid moisture issues in the near future or seeing what may already be damaged.

Loose fill insulation would be a cost effective solution for acoustic, spray foam insulation (closed more than opened cell) is more for thermal properties than acoustic.

Edit: also assuming these are all interior partitions and not exterior walls.

Sent from my SM-G781W using Tapatalk
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The walls are exterior with lath and plaster on the inside. Stripping that and doing drywall would be the ideal. However the drywall would be thinner and all the baseboards would end up undersized unless the drywall was shimmed out or thicker (5/8") used. I don't know if full sheets of drywall can get up the stairs.

The logistics lean towards working from the outside while the siding is being replaced.
 
Although I am in the foam industry, I am not in the spray foam industry. Regardless, messing with foam chemistry is not something that should be done without experience. I would avoid those DIY foam packs. If you mess up the Isocyanate ratio, you are in for a lot of headaches literally and figuratively. Some things should only be left to the pros that guarantee their work. Spray foam is just one of those things.

You definitely DO NOT want to apply spray foam through a hole and hope for expansion. The product is a science.

 
Old houses , second floor, we have used 2 layers of 3/8 drywall to make it thickness of old plaster. One long knife cut , fold sheet to 2x8 take up stairs unfold and install.
But now you have 3,000lbs of old plaster to toss out a window.
I think I'd either go the blown cellulous in from the top, or sheath the outside of the building with foam panels before installing siding. Most siding guys will do that job.
Cleanest, fastest and cheapest will be 1, 1 1/2 " foam panels on outside
7/16 OSB is $36.00 sheet this morning , $32 for shop grade if you can find any.
 
crankcall said:
Old houses , second floor, we have used 2 layers of 3/8 drywall to make it thickness of old plaster. One long knife cut , fold sheet to 2x8 take up stairs unfold and install.
But now you have 3,000lbs of old plaster to toss out a window.
I think I'd either go the blown cellulous in from the top, or sheath the outside of the building with foam panels before installing siding. Most siding guys will do that job.
Cleanest, fastest and cheapest will be 1, 1 1/2 " foam panels on outside
7/16 OSB is $36.00 sheet this morning , $32 for shop grade if you can find any.
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Pretty much shreds the 2019 $1600 price for applying the OSB. 20-25 sheets, lots of waste.:(
 
JZ67 said:
Although I am in the foam industry, I am not in the spray foam industry. Regardless, messing with foam chemistry is not something that should be done without experience. I would avoid those DIY foam packs. If you mess up the Isocyanate ratio, you are in for a lot of headaches literally and figuratively. Some things should only be left to the pros that guarantee their work. Spray foam is just one of those things.

You definitely DO NOT want to apply spray foam through a hole and hope for expansion. The product is a science.

Click to expand...

I have some 2 part liquid I plan to use for floatation on a canoe. I used a bit to pack a delicate item for shipping. Pour a little in the box, cover with a plastic bag, set object on top. Suddenly the object is at the top of the box, not middle for a second pour. Fortunately I was able to contain the mess or I would be spending weeks scraping the stuff off of said object. Temperatures are deadly critical.

I did some experimental line heating for the stuff so the manufacturer could keep production up and costs down when plant temperature varied. Definitely not for the average home owner.

One guy I know that had the exterior of his beater site car foamed at a job in northern Quebec when the heater couldn't keep up. It looked like a giant yellow turd and every dog walker knows they're warm.
 
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