# Interesting idea on reusing foam



## fishhead (Jul 19, 2006)

I was talking with a friend yesterday and she brought up the idea of chewing up those annoying styrofoam inserts that come with most large items. Then using it to blow into wall cavities just like cellulose.

There seems to be plenty of those inserts around for the asking. I'll bet a person could insulate a home with them.


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## Colcordmama (Jun 26, 2010)

fishhead said:


> I was talking with a friend yesterday and she brought up the idea of chewing up those annoying styrofoam inserts that come with most large items. Then using it to blow into wall cavities just like cellulose.
> 
> There seems to be plenty of those inserts around for the asking. I'll bet a person could insulate a home with them.


I bet you could do that. I don't know what the R rating would be for such a use, but if it weren't high enough, you'd have gone to all that trouble without a worthwhile result. I've always wondered if those chunks could be chopped up small enough if you could use them to fill a beanbag chair. I know you can use packing peanuts (ghost poos) for that, so I'm already saving any I get.


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## SolarGary (Sep 8, 2005)

fishhead said:


> I was talking with a friend yesterday and she brought up the idea of chewing up those annoying styrofoam inserts that come with most large items. Then using it to blow into wall cavities just like cellulose.
> 
> There seems to be plenty of those inserts around for the asking. I'll bet a person could insulate a home with them.



Hi,
There is the fire rating to think about -- the cellulose is treated with a fire retardant.

Regular rigid foamboard Styrofoam insulation (the white stuff) is made from recycled foam, and has an R value of about R4 per inch of thickness.

Gary


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## fishhead (Jul 19, 2006)

I wouldn't think the fire rating would be much different than rigid foamboard.

Now I'm wondering if foamboard is legal to use in wall cavities. I put 1" blue foam underneath my siding last fall and it made a huge difference. The same friend said that it wasn't as much a vapor barrier as I thought.


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## artificer (Feb 26, 2007)

fishhead said:


> I wouldn't think the fire rating would be much different than rigid foamboard.
> 
> Now I'm wondering if foamboard is legal to use in wall cavities. I put 1" blue foam underneath my siding last fall and it made a huge difference. The same friend said that it wasn't as much a vapor barrier as I thought.


Foam board is legal in cavities as long as it is covered with a fire resistant material like sheetrock/drywall/gypsum board.

If it was the blue extruded foam board, and you taped it, it IS as good as you think it is. If it was the expanded, made of little beads, type of foam, then that is less of a vapor barrier. Still better than fiberglass, however. The fan fold sheets that they have for under siding use (1/4" thick?) has many holes in it to let moisture escape. You don't want moisture barriers on both sides of the wall, or you can get moisture problems.

Michael


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## taylorlambert (Jul 4, 2010)

At the landfill dad and I run we get a 40 cubic yard a=uger dumpster thats full of bb's. Its the router dust off of the foam panels from the RV plant. I had a man ask about them and even though scavenging is against the rues we filled some shower stall bags with the bbs. The man was doing an attached garage to make a family room with a roll up door. The garage had 2by 4 studs with an outer wall and the inside was plywood. He had little cut outs in the tops of the wall that had a hose he fit to the cutout. 

Then he hooked a sholp vac in a similar hole in the bottom of the panel with a sock over the end of it. just turn the vac on and then stick the top hose in the bags of bb's and it would fill the panels then shut off the vac and plug the holes. One small window unit cools the whole room. 

He contacted mea few days agoand asked me about some more bb'sto fill his new cabin he is building.


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## fishhead (Jul 19, 2006)

Maybe the RV plant should start bagging and selling the bb dust or you could.


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## mightybooboo (Feb 10, 2004)

In a fire its smoke,not flames that kill most folks. I would be very leery of toxic smoke,think its a bad idea at least for me.Get fire retardant cellulose if you want to be safer ,that stuff can take flame.

Dad used to sell it.Would take a brick sized lump,hold it in his hand and take an acetylene torch and melt penny on his hand.

Which do you want in your wall,a toxic mess or a product that can take a torch and not burn?


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## gobug (Dec 10, 2003)

I have had an interest in using second hand foam for a long time. In addition to the comments above, foam can become a nest for a variety of pests (molds, ants and mice mostly). Termites go through it to get to wood. The foam which has some boric acid prevents the above problems.

Another complication not mentioned is the zoning board. I asked the head of the building inspection department in my county if I could make my own insulation using paper made into a cellulose fiber type of insulation. His comment was that I could do it, but since it is not manufactured, there are no details to prove it complies with code. He said I could have it tested, but cost would be thousands higher than just using a marketed product.

Adding foam beads to a custom cement mix can result in a very strong product with an R value of about 3 per inch. The alkylinity of the cement eliminates most of the pest problems. The addition of a small percentage of boric acid to the mix eliminates most of the fungal or mold risks.

I looked for discard foam throughout the Denver area without success. I could buy the beads in bulk (like cubic yard). There should be a lot of businesses that discard the stuff, it is just hard to find them and find the person in the business to talk to.

I used a left over piece of foil backed polyisocyanurate foam for the form for a plant room sink in my basement. I covered the foam with hardware cloth then cement 1/8 inch thick. It worked fine.

gary


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