spongy insulating layer General Building and Construction Discuss spongy insulating layer in the General forums; Hi All, I poured my insulating layer of vermiculite and Portland cement about four days ago. It feels a little ...

[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]

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]

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]

Yep, normal.

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

[DaveW]

Thanks, it sounds like I can move forward.
Dave