Replies

1. 
   rjw | Dec 18, 2003 10:36pm | #1

   Might be hard to find - it's being (been?) checked for asbestos concerns

   http://www.epa.gov/asbestos/vermfacts.pdf

   http://www.epa.gov/asbestos/insulation.html

   _______________________

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   Tool Donations Sought

   I'm matching tool donors to a church mission to Haiti - we're shipping a bus converted to a medical facility in January (we hope) and can fill it with clothes, tools and all sorts of stuff needed in that poorest of all countries. A few hand tools or power tools can provide a livelihood for an otherwise destitute family. Please email me if you have tools to donate.

   Thanks to Jeff and David and Jim for their offers!

2. 
   csnow | Dec 18, 2003 11:07pm | #2

   I have not heard of the water repellent perlite you speak of. 

   I cannot imagine a loose fill that I would be comfortable using against a concrete block wall.  Too much moisture migration from the soil.  That poly 4 inches away would only make matters worse.  Think of it as a dam, trapping moisture in the perlite.  Bet that cavity is rather wet right now. In a basement, the vapor/moisture load is inward.  Concrete block is like a wet sponge. You want a moisture barrier directly against the block wall.

   I have read a lot about these injectable closed-cell foams, but have no first hand experience with it.  Seems like something to consider if you do not want to replace the walls.

   If you rip it out and rebuild, consider using a material like Tu-tuf, covered with rigid foam.

1. 
   TEConnor | Dec 22, 2003 06:07pm | #6

   Thank you all for the replies.

   Schundler (a perlite distributor) returned an email of mine and I was able to find a local supplier.  I asked about the water repelling treatment for Perlite, and this is the type of insulation that is recommended for masonry application (such as filling inside concrete block).  So it is available, the question is, however, should I use it.

   I do understand about the concrete block walls being a moisture seive.  If filling the void with any loose fill material would only serve to create moisture accumulation problems (ie, mold) then I will stay away from it.

   Thinking about what I can do to the walls a little more, I believe that I can cut and repair the drywall as much as I want...that's something I have been doing for the past year anyway to repair and upgrade the electrical system.  Perhaps the closed-cell expanding foam is the way to go in order to alleviate moisture problems.

   Hence, although the idea of blowing in a cheap material like Perlite seems a good idea on first brush, in thinking it over the moisture trap is too big of a concern.

   Thanks,

   Tim

3. 
   mike4244 | Dec 19, 2003 01:26am | #3

   Tim, I have bought vermiculite which I believe is similar to perlite. Try a farm supply, vermiculite is mixed in clay soils for bedding plants, aerates the soil.

   Make sure there are no holes in the drywall as perlite will seep thru small holes or gaps. Your receptacles and switch boxes need special care. Tape up unused knockouts and take care of gaps between boxes and rock. You can probably stand in one spot and pour at least 50% of each wall , that's how easily perlite flows.

   Mike

4. 
   4Lorn2 | Dec 19, 2003 01:26am | #4

   This stuff, Pearlite, is easiest to get from a garden supply center where it is used as a potting soil amendment. Local HD has it in big bags, something like 4 cu ft, for a couple of bucks.

   No expert but I understand it is fairly impervious to moisture, fire, rot, insects, etc. I wouldn't think it would draw moisture any worse than the existing concrete. Pour it in and let it set. I have worked on a few homes with it in the hollow cores of the block walls.

   Only problem is that any hole, anything bigger than about half inch square, will allow the Pearlite to pour out. A fairly impressive prospect when you remove a box, making the hole a bit bigger, near the baseboard, without knowing about the filler, and the Pearlite in the wall, 10' of it, attempts to redecorate the room. Yet another reason to carry a bandana as it can be used to stuff the breach.

   I would wear a good mask pouring it in and cleaning up but would think that once in place it would pose little danger.

   Vermiculite would be much the same but it might absorb more water. I don't know too much about it.

5. 
   BKCBUILDER | Dec 19, 2003 02:28am | #5

    Around here we use a product called Zonalite, which is just another form of perlite, same stuff. Masonry supplier is the best bet, that's where we get it. Pour till your heart is content, as stated above it goes everywhere.......