5" Insblok

[JRPizza]

I was planning on using insulated concrete plus about 2" insblok-19, but found a good price on the board and am thinking about going 5" thick and putting it directly on the concrete hearth. I know lots of folks have used Insblok successfully - has anybody gone up to 5" thick? Other than the possibility of settling is there anything I should be considering with the extra thickness?

[gugahulk]

I have 6 inches and my oven drops 25f per day. I lose almost not heat.

[JRPizza]

Great, so my planned 5" should work pretty good. Did you find the Insblok pretty easy to work with? Any tips you could offer?

[gugahulk]

Yes very easy to work with, just use an angle grinder to cut it with and it will cut perfect everytime. Dont use too much sand to level the bricks, I made the mistake of putting alot of sand. Than took it all out and used ZERO SAND.

[JRPizza]

Thanks - will pick up a respirator when I get my boards - I understand that stuff is nasty to breathe and I can envision particles flying all over during cutting. If I have any more questions about the Insblok I'll either post them or send you a PM.

[JRPizza]

Hey Gugahulk, what thickness of boards did you combine to get your 6"? My vendor failed to let me know that the 2.5 inch weren't in stock and will charge me an extra $50 to receive them in. I can stack either 1.5 or 1" boards to get to 5 for less cost than the new price of the 2.5's

[JRPizza]

I am waiting for my 2.5 inch to come in, but it won't arrive till at least next week. Can anyone comment on how accurate the 12" by 36" dimensions are? I want to start cutting bricks and my dome outside diameter is targeted at 48". If the blocks run small I risk over hanging if I precut.

[Gulf]

I think that it is pretty close. At least the CalSil that I had, was. But, you can always shift your insulation forward and to the side. There will be plenty of off cuts to fill in with. I like the diameter of the floor insulation to be an inch or two bigger than the foot print of the dome.

[Gulf]

I just remembered that you are doing two layers of insulation. You may have thought of this already. If not, you can rotate your second layer 90 degrees. Shift it the oppesite directions that you did the first. Now, none of the seams of the two layers will fall directly on top of one another.

[JRPizza]

Thanks - I had figured on staggering my two layers to avoid overlapping seams, but was planning on getting pretty close to the edge as a 39" ID will give me a 48" OD. Other than any bearing strength reductions from being close to the edge (don't know how to account for edge effects) I figured I'd wrap the insulation blanket down over the insulating block and make up for any reductions in insulating effect. I'm kind of committed on the size/quantity of block, so I hope I don't need to shrink my oven any.

[Gulf]

There is probably no real reduction in strength with the dome sitting close to the edge of board insulation. Having a vcrete layer a littler large than the foot print of the dome was recommended to me. So, I just carried that on into my board insulation layer as well. That's just me . Your layout is fine. I did wrap my last layer of blanket over the board insulation. Anyway, I think that you can proceed with your cuts. I wouldn't wait on the insulation. And, I definitely wouldn't change the size of my oven. Not, with all the cut offs that can be used.

[gugahulk]

Hey Gugahulk, what thickness of boards did you combine to get your 6"? My vendor failed to let me know that the 2.5 inch weren't in stock and will charge me an extra $50 to receive them in. I can stack either 1.5 or 1" boards to get to 5 for less cost than the new price of the 2.5's

Got it from Forno Bravo, when you buy it, they say its 2.5 but when I got it, I mesured mine and they were all 3 inches and some 3.1 Super thick. So I combine both. Yes use the raspirator that thing is nasty. Sorry I didnt reply before, with this new forum I get no notification that you posted. I hate this new forum.

[Gulf]

....................Sorry I didnt reply before, with this new forum I get no notification that you posted. I hate this new forum.

Check the Notifications tab on your User Settings page. Make sure that it is set to ON or ever how frequent you want to receive them. Lately, mine had been set to Daily. I was getting all my notifications about 7:00 pm each night. I'm going to just select the On setting and see how that works for a while.