Vermiculite cement under oven floor

[mokomon]

i want to use vermiculite cement for under my oven floor. Will it be quite strong at 5:1 ? or should I pour regular cement on to the base around the vermiculite mix and level to it , to entrap it?

[UtahBeehiver]

Minimum 4" of 5 to 1 which is equal to about 2" of CaSi. I suggest you make a single build thread and ask all you questions on that thread. It keeps everything centralized rather than threads all over the place.

[Pizzarotic]

i want to use vermiculite cement for under my oven floor. Will it be quite strong at 5:1 ? or should I pour regular cement on to the base around the vermiculite mix and level to it , to entrap it?

Yes, 5:1 is strong enough but not on the edges. It needs to extend out from the dome several inches at least, where it has more support. The dome should not be supported on the edge of the vermiculite.

You can cast it inside a concrete well providing it has good drainage below and is reasonably weather proof otherwise it can help trap the moisture and lead to poor performance which also applies if cast on-top of the slab.