vermiculit

[david s]

Re: vermiculit

Does anyone have an idea how many cubic feet of vermiculite I should have available to cover a Premio2G100 with a 2" layer of vermicrete? I was thinking of using 8:1 but I noticed in the stream 10:1 was used as well.

The more cement you use the less it will insulate. Some builders go as much as 13:1, but I find it doesn't stick together so well. I find 10:1 workable. if you are doing an enclosure it is better to fill between the oven and the enclosure with loose dry vermiculite or perlite, because both cement and water reduce insulation value and the water needs to be removed. If you plan on an igloo finish then you have to add the water and cement, because the mix needs to stand up on its own and be firm enough to render over.a 2' layer of vermicrete is insufficient insulation on its own over the dome IMO. You need ceramic fibre blanket between the dome and the vermicrete layer.

[campbelloakland]

Re: vermiculit

It has been a while but we set the Premio2G100 oven in place which was no easy feat. When my sons showed up they were wondering what I was doing with a gantry in my truck. They soon found out, it was the only way to get the pieces on top with the limited space we had. Anyway, it is all cemented together and has dried out during the week. The thermal blanket and chicken wire go on tomorrow and then the vermicrete.

Hopefully my last question. Not being a mason and all I have read and see two different approaches for applying the rendering/stucco over the vermicrete. In one case they put another layer of chicken wire the rest they only say they apply the stucco to the vermicrete. When I see masons apply stucco to block walls they moisten the blocks before application which in this case defeats the curing of the vermicrete. Any recommendations....I just want to do it right. Some day I will get the pictures downloaded and show you our project. We are having a blast with this!!

[david s]

Re: vermiculit

I don't like to add anymore water to the vermicrete layer especially after removing it all, but I prefer to wrap the whole oven in cling wrap after the stucco layer and let it cure for a week.if you do more than one layer of stucco then just wrap it after the last layer.This technoque does a pretty good job, you can see the moisture trapped under the cling wrap.

[Greenman]

Re: vermiculit

The vermicrete is not particularly 'sticky' and the chicken wire over the Ceramic Fibre certainly helps hold it in place until it goes off properly. The stucco keys into the vermicrete very well due to the surface and IMHO there is no real need for reinforcement there. If you feel the need for reinforcement then fibres in the render will do the job fine.

It will be interesting to see your pics when you put them up.

Cheers ......... Steve