Forno Bravo Forum: The Wood-Fired Oven Community

Forno Bravo Forum: The Wood-Fired Oven Community (http://www.fornobravo.com/forum/)
-   Pompeii Oven Construction (http://www.fornobravo.com/forum/f8/)
-   -   vermiculite alone or mix with concrete (http://www.fornobravo.com/forum/f8/vermiculite-alone-mix-concrete-16326.html)

jdefeo 07-11-2011 11:32 AM

vermiculite alone or mix with concrete
 
Greetings,
my 43 inch Pompeii oven is up and running. I had some heat stop mortar left over so used it on the top of the dome. I was going to insulate the dome with plain vermiculite but wondering if I should get anothe bag of heat stop and put it all around the dome first or is this needed?

Also, is it better to go with plain loose filled vermiculite around the dome or better to use a concrete vermiculite mix? If mix, what ratio do you use?

any suggestions are appreciate.
Joe

dmun 07-11-2011 12:01 PM

Re: vermiculite alone or mix with concrete
 
If you have a suitable enclosure, there's no reason not to use loose vermiculite. It insulates slightly better than vermiculite concrete, and there's less to carry, mix, and apply.

It can leak out of surprising small openings. Check your enclosure with a strong light, and assume that if there's a light leak, there could be a vermiculite leak as well.

You can block off corners of a cubic enclosure to reduce vermiculite use.

Neil2 07-11-2011 04:03 PM

Re: vermiculite alone or mix with concrete
 
"Also, is it better to go with plain loose filled vermiculite around the dome or better to use a concrete vermiculite mix? If mix, what ratio do you use?"

If you do add cement, make it a very weak 12:1 mix. This will insulate almost as well as loose vermiculite. Some have done this to make sure the vermiculite stays in place and to prevent loose vermiculite from blowing around/sifting out of their enclosures. You might consider this if you are doing a well ventilated enclosure with large under eave openings.

mrchipster 07-19-2011 08:34 AM

Re: vermiculite alone or mix with concrete
 
Instead of adding cement to the vermiculite to keep it from moving around in a well vented space just get some aluminum flashing material and place it over your vermiculite it comes in up to 36 inch widths here in Minnesota and wit a 6 inch overlap will keep the vermiculite in place without the added water required to do even a 12/1 mix.

Or for a tight fit get a piece of aluminum soffit (un-vented) It comes in 12 ft lengths and 1 - 2 pieces should be able to cover the top of the oven space nicely. The pieces are slightly corrugated and slide together easily and will provide a nice tight cover to keep things from moving arround.

Chip

jdefeo 07-19-2011 08:38 AM

Re: vermiculite alone or mix with concrete
 
mrchipster,
thanks for this idea. I'm about to start framing it in and was going to use cement board to hold my vermiculite in (then a wood frame outside of that for finishing). Your idea sounds easier than cutting a lot of cement board to go around a dome!
Many thanks, wil look to see what sizes I can get out here in connecticut.
Peace,
Joe


All times are GMT -7. The time now is 10:18 PM.

Powered by vBulletin® Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Search Engine Friendly URLs by vBSEO 3.6.0
2006/10 Forno Bravo, LLC