Waterproofing the vermiculite slab

[Harpist]

Hi folks,

The dome is complete and enclosed with backer board. I am hoping to get the outer facade done before the North Idaho winter hits. However, I won't get the counter-tops done before the snow falls. So this leads to a question regarding the vermiculite slab.

The vermiculite slab extends beyond the base of the dome and as such, wicks water into the floor of the oven. Once I get a counter top on, this will be fine. Is there a temporary way of waterproofing this so as to keep it a bit drier (that can later be covered with thinset?).

Thanks for all your assistance through this project. I have not laid bricks in 35 years and - without this forum - I don't think I would have tried this! For anyone interested in the project, my better half has been documenting the project stages on Google's Picasa.

Good Roads

Harpist

[Neil2]

"The vermiculite slab extends beyond the base of the dome and as such,"

Tarp it over. Any thinset or render will crack at the juncture anyway.