Can I use P-Crete....

[mrramsey]

So as I am still trying to wonk out some issues in my design I had a question. Can I use p-crete to more or less 'shape the outside of my dome to make it not a dome? In this pic you can see what I am trying to do. There will be 2" of ceramic fiber insulation and then 2" of p-crete. What I want to do is build up the corners where the fire brick is essentially covering the firebrick completely to help eliminate water getting into the floor. I don't want to do a full enclosure because the location where this will go is right below a bank of windows on my house. and if I have a large roof structure it blows the view because you would be looking at the side of a roof.

A stucco dome is a lower profile. I would imagine that there would not be any issue with doing so but thought I would ask first. Oh and since someone will bring it up this is a one piece, 42" cast that is cast in place so I need to cast on top of the floor. At least thats how my forms are designed at the moment.

[Les]

Once you are insulated you should be good to go. If you can swing it I would go thicker then two inches. You will thank yourself later.

[mrramsey]

Once you are insulated you should be good to go. If you can swing it I would go thicker then two inches. You will thank yourself later.

I assume you mean thicker on the blanket? I may it's only $100 for another inch.

[Les]

Yes, insulation is everything. You will appreciate the fact that you can cook something three days after the fire.

[david s]

Perlcrete or vermicrete is an ideal material to do what you are intending. If you make it lean it is also an extremely good insulator. A mix of 10:1 with a little (around a handful for every litre of cement added) of powdered clay works well. Make sure you add the correct amount of water to the mix, which is which is just a little less than when the water begins to pool in the bottom of your barrow. This will be around 3 parts water fo 10 parts vermiculite or perlite and 1 part cement, by volume, but the water addition needs some adjustment depending on the grade of the vermiculite or perlite, the finer the grade the more water is required. I find a 50/50 mix of perlite and vermiculite makes a superior mix than using either of them alone.

[mrramsey]

Perlcrete or vermicrete is an ideal material to do what you are intending. If you make it lean it is also an extremely good insulator. A mix of 10:1 with a little (around a handful for every litre of cement added) of powdered clay works well. Make sure you add the correct amount of water to the mix, which is which is just a little less than when the water begins to pool in the bottom of your barrow. This will be around 3 parts water fo 10 parts vermiculite or perlite and 1 part cement, by volume, but the water addition needs some adjustment depending on the grade of the vermiculite or perlite, the finer the grade the more water is required. I find a 50/50 mix of perlite and vermiculite makes a superior mix than using either of them alone.

Thanks David. That's what I was after. Was looking to add some cosmetic form without the thermal mass.