poolcrete

[mc511]

has anyone else tried using poolcrete for insulating instead of fire brick? It is a vermiculite concrete used for bottom of pools. I used it to line the evaporator I built last year and it worked great. At full burn, I can hold my hand to the side of the firebox for several seconds and not get burned. Found it to be a lot more cost effective than fire brick. I lined it with about two inches of poolcrete throughout the arch. Just wondering if anyone else tried it and how it worked for them.

[maple flats]

never heard of it before, I wonder what the insulating value is? Also, I really doubt it is rated for heat. The concrete portion is most likely just portland and sand, maybe some aggragate, maybe the vermiculite is the agg.

[spud]

If it works and saves you money then go for it. I have never heard of that being used.

Spud

[mc511]

yes, the vermiculite is the aggreate. vermiculite was used for insulating houses back in the day. pool installers use it for pool bottoms under the pool liner, it allows water that gets under the liner to drain away. I also read that people who built outdoor wood fired pizza ovens used it for insulting on the outside of the firebrick. Anyway, used it this last year and it seemed to hold up pretty well.

[Wood burn]

I was told vermiculite was bad for you and if you've got it in your attic it should be removed . I also am looking for a cheap way to insolate my arch .

[mc511]

the stuff i got from the pool install guys was a dry permix, just added water. Would recommend a dust mask though. other than that, was like using quickcrete, just not as heavy. vermiculite concrete is pretty light compared to quickcrete. and the vermiculite is moisten so it dosn't produce much dust. Once dry, really hard for it to get out of the mix.

[heus]

Vermiculite is only bad if it came from the Libby mine in Montana (or is it Colorado?) years ago. They hit a vein of asbestos and some of the vermiculite had traces of asbestos in it. Most vermiculite is safe from what I have read, especially if its new.

[moeh1]

You can also make perlcrete using perlite and portland for the mix. I'm using it under the firebrick floor for a pizza oven. I hadn't seen it used in direct contact with the fire, I'm not sure how the portland would like that. The insulation value seems to be about 1/2 that of ceramic blanket.
Marty

[ejmaple]

I would only use it under the flue pan ( dry ) as a filler, then use half bricks on top. this has worked well for me.