spongy insulating layer

[DaveW]

Hi All,
I poured my insulating layer of vermiculite and Portland cement about four days ago. It feels a little spongy on the edges...Is this normal?
thanks,
Dave

[Breven]

Re: spongy insulating layer

I think that is proabbly normal. I noticed the edges were a bit fragile on mine as well. The brick floor will displace the weight evenly over the entire insulating layer...should be real sturdy. Of course, that is assuming you used the correct vermiculite/cement ratio.

[dmun]

Re: spongy insulating layer

I poured my insulating layer of vermiculite and Portland cement about four days ago. It feels a little spongy on the edges...Is this normal?

This is normal, it takes a week to harden to the cork-like consistency, and it still will be crumbly around the edges.

[Neil2]

Re: spongy insulating layer

Yep, normal.

Everyone reports it as looking "spongy" but it will support a surprising load.

[DaveW]

Re: spongy insulating layer

Thanks, it sounds like I can move forward.
Dave