Insulating layer finish

[DimTex]

I just finished pouring the portland and perlite layer and after the overnight set the surface looks, very spongy looking (like a dry sponge). Is this the way its supposed to finish out? Do I need to skim a thin layer of mortar or portland cement to "seal" and "stabilize" it? Will it support the weight of the floor and dome without compacting?

[dmun]

Re: Insulating layer finish

Without fail, everyone who uses vermiculite concrete for the first time thinks it's weird and won't hold the weight. It will, if you followed the directions. Also, it needs a week to set up: vermiculite holds a LOT of water.

[130mountainside]

Re: Insulating layer finish

Thanks...its 24 hrs and it still seems spongy....wait a week before ripping it out?...haha