Calcium Silicate board thickness

[brickie in oz]

Re: Calcium Silicate board thickness

My big issue is that it is going on top of only 1.75" of true concrete. I am thinking I might just double it up so that I dont have any regrets. Follow up question though...How important is insulation under the entrance/hearth? My entire floor will have almost 4" of CalSil, but my hearth is going to only have 4" of vermicrete. Is this going to compress at a different rate than the CalSil?

4" is just over kill and a total waste of money.

[Salty]

Re: Calcium Silicate board thickness

My big issue is that it is going on top of only 1.75" of true concrete. I am thinking I might just double it up so that I dont have any regrets. Follow up question though...How important is insulation under the entrance/hearth? My entire floor will have almost 4" of CalSil, but my hearth is going to only have 4" of vermicrete. Is this going to compress at a different rate than the CalSil?

[brickie in oz]

Re: Calcium Silicate board thickness

I used 40mm thick which is about 1 and a 1/2", it will keep the oven hot for days on end.
Mind you, our climate is Mediterranean like.

[Les]

Re: Calcium Silicate board thickness

I thought 2 inches was standard. I went with 4 inches and have zero regrets. Personally I would double up. It won't impede your progress of pouring the foundation so no hurries...

[Salty]

PLEASE HELP. I am ready to pour my foundation this weekend. I have 3 pieces on calcium silicate insulation but it measure at about 1 5/8". Other than that issue, it is definitely the good stuff, I bought it at Western Industrial Ceramics. So here is question....Is one layer enough? or should I my more so that I can double on to 3.25-3.5" of calcium silicate. Please help.