Calcium Silicate board thickness

[Les]

Re: Calcium Silicate board thickness

so...I sucked it up and bought another 1.5" of CalSil to add to my floor insulation. I was reading the forum posting about what people would change if they did it again and way too many people said "add more floor insulation" for me to ignore it (sorry Al, better safe than sorry)

Personally I think you made the right call. Over insulating over, under, or on the sides will do no harm.

[Salty]

Re: Calcium Silicate board thickness

so...I sucked it up and bought another 1.5" of CalSil to add to my floor insulation. I was reading the forum posting about what people would change if they did it again and way too many people said "add more floor insulation" for me to ignore it (sorry Al, better safe than sorry). I sourced it from a different location this time. Less than a mile from my work and the 1' x 3' x 1.5" boards were $19 each.

Also, I noticed they had boxes upon boxes of ceramic blanket lined up so I asked the guy if they might have some end cuts floating around that I could purchase. He laughed and said they had dumpsters full of the stuff. He said if I come back when his boss is around they will fill my truck with blanket scraps at no charge. Not too shabby.

Also, anybody know anything about transite? He said all the pizza shops around town buy it for their pizza stone. Its expensive stuff but he had a bunch of end cuts of that also.

[david s]

Re: Calcium Silicate board thickness

2" of cal sil is approx equivalent to 4" vermicrete Both are considered adequate. Doubling is subject to the law of diminishing returns.

[Salty]

Re: Calcium Silicate board thickness

Too late now.

But I still need to make my CalSil decision. I keep waffling whether to double up or not still.

[david s]

Re: Calcium Silicate board thickness

Sorry, I should have explained more. My build is going on a custom made steel cart. On top of that I have a 14 ga galvanized steel pan with welded reinforcements. This pan has been bolted to my cart and I will be filling it with the < 2" of concrete. My build blog is Mobile Oven in Oregon...I'll be updating it much more often now that I am further under way.

To increase the strength of that thin concrete slab you can add fibres. There are all kinds, plastic ones should be fine, the slab will not get hot enough to melt them.You can also increase the strength substantially by using a super plasticiser and an ad mix, but you will need to do some research and go to a concrete supply merchant. By making the slab stronger you can then make it thinner and save a heap of weight.

[brickie in oz]

Re: Calcium Silicate board thickness

Al,

Do you have Vermicrete under your calsil or is it regular concrete?

Just 100mm of plan ordinary everyday concrete.

[Gulf]

Re: Calcium Silicate board thickness

I know what you mean. I owe some friends who helped me with a little metal work and material aquisition.

Also, use only hand tools to cut the calsil. A key hole saw cuts the curves just fine. A hand saw will work great on any straight cuts. These type tools help keep the dust down. Do wear a dust mask! Buy the wet saw and sell it to your neighbour when you are finished with it. He will want a WFO too, if you invite him over for the great food . It is that "keeping up with Jones' syndrome" that makes this all work .

[Salty]

Re: Calcium Silicate board thickness

For the most part it is out of my league too, but I brought up the idea to the guys in the shop where I work and before I knew they were cutting steel tubing for me...ha...Now I am on the hook to get this thing done ASAP.

It is like losing weight...dont tell people you are going to do it if you dont want to be held accountable.

[Gulf]

Re: Calcium Silicate board thickness

I knew that I must have been missing something. Thank's for the clarification. Steel construction is a little above my pay grade .

[Salty]

Re: Calcium Silicate board thickness

Sorry, I should have explained more. My build is going on a custom made steel cart. On top of that I have a 14 ga galvanized steel pan with welded reinforcements. This pan has been bolted to my cart and I will be filling it with the < 2" of concrete. My build blog is Mobile Oven in Oregon...I'll be updating it much more often now that I am further under way.

[Gulf]

Re: Calcium Silicate board thickness

Salty,
I wont get into the thickness of the calsil since I don't know how less than 2" perform. What does concern me is that you stated that: "My big issue is that it is going on top of only 1.75" of true concrete"

I may have missed something but, that is just a little over counter top thickness. Not a true weight bearing thickness for a WFO hearth. Is this 1.75" poured on top of some other load bearing structure?

[Salty]

Re: Calcium Silicate board thickness

Al,

Do you have Vermicrete under your calsil or is it regular concrete?

[brickie in oz]

Re: Calcium Silicate board thickness

Al, Are you sure about that?

Ive only got 40mm of calsil and nothing else under the hearth and after a pizza night we can cook for a week in the oven.

So I am just guessing that 100mm is overkill.

P.S. The hearth only has a thermal mass of 100mm.

[Les]

Re: Calcium Silicate board thickness

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

Al, Are you sure about that? I recall reading where some have measured a termperature rise on the bottom of the hearth. I can see it being overkill if you are sitting that thick of board on top of vermiculite.

[Salty]

Re: Calcium Silicate board thickness

Aww Man...Now you have me second guessing doubling up. It certainly would be cheaper to only have one layer. What is the best way to cut the CalSil? Band Saw? Table Saw? Circular Saw?

Also, has anyone tried cutting their fire brick with a table saw with a diamond blade? It obviously isnt a wet saw, but I think that is the best I can do without a big investment.

Now, that I think about it....with they money I save not buying more CalSil, I'll be able to buy the diamond blade...I would guess that is a fair trade off.