Insulation blanket, ceramic insulating tape?

[Neil2]

Re: Insulation blanket, ceramic insulating tape?

Concrete counter tops are an easy, inexpensive and very practical solution.

Some suggest poring the countertop into a mold and then turning over, but you can achieve the same result with a "face up" approach.

Pour it as you would any reinforced slab. 1 1/2 inch thick is enough. Add some concrete dye if you want.

The interesting part is the grinding and finishing. I do the initial grinding when the concrete is still somewhat "green", 3 days or so after the pour (keep it wet). This is done with diamond grinding cup on a 5 inch grinder. I cut it down 1/8 inch or so to expose the aggregate. Don't worry about it being level - if you make the same number of passes and don't linger in one spot it seems to work out OK. Chamfer the edges and round the corners at this stage. Fill in any pockmarks or air holes:

Finishing Concrete Counters: How to Cure, Grind, and Polish a Concrete Counter Top | Suite101.com

I wait at least two weeks (keeping the slab completely saturated with water the whole time) before starting the polishing. The concrete will be hard enough at this stage so that bits are not picked out by the polishing pads. I used a set of diamond pads (50 grit to 3000 grit) and polish wet. You can get to a mirror finish. Below is one I did with a green dye (also a picture of my 5'4" wife).

After final polishing and buffing, I let it dry out completely and have use a wetting product such as "Enrich-n-seal" to bring out the colour of the aggregate. This is heat proof and food safe.

The whole process is very messy. Do it outside and rig some poly screens to protect the surroundings.

It is labour intensive so I strongly suggest you do some test pieces first - benches, stepping stones etc, and experiment with the colour and the grinding depth.

[azatty]

Re: Insulation blanket, ceramic insulating tape?

After doing some research, you may not be overthinking the heat break. Marble apparently falls victim to "thermal hysteresis.". I gather from my reading that uneven heating of marble can cause part of the tile to delaminate. It is apparently observed at low temperatures, too, and is a concern when determining how to face buildings with marble. You may want to spend some time looking into the issue.

[Xene]

Re: Insulation blanket, ceramic insulating tape?

Thanks @azatty, I did do some research on marble and I'm torn as to which way to go, considering I like this marble piece I have an awful lot...but I don't want to have paid for it to be shaped and have it split on me, thanks for leading me to that thermal hysteresis problem. I'm going out to the stone cutters the first of this week to talk with them, as I know granite is far more resilient.

So I'm still not clear on how I would need to use the ceramic tape, what is the best thing to use to seal it into the joint? Do I have to seal it? Could I just set it in the joint between the oven brick and the granite/marble as long as it was recessed in the joint and let a bit of ash cover the gap? How thick is this stuff?

I've been busy getting the entry built up, I was about 4 inches short on the hearth, so I built out my granite arch and then added brick to make up for my shortcomings (yes, this making up for errors is a theme I have going on with this build, but it's all good) I'm pretty happy with it so far. Ultimately I save a enough time by not planning anything that I can make up for it in rebuilding it () HA!

I have to take this ceramic tape/heat break seriously though. Is there something else I should consider? There are 2 layers of FB board under this entrance just to get it to the height I need. The picture shows a mock up out of wood cut to 3/4 inch thickness, the same as my marble, but I have allowance there for more, knowing standard granite is twice that thickness.

Do I need a heat break at all if I use granite? Thanks all!

[Les]

Re: Insulation blanket, ceramic insulating tape?

Do I need a heat break at all if I use granite? Thanks all!

Granite can spall from heat as well. I just found out the hard way. I cut a piece for my garden window with a dry blade. I was just told yesterday that it cannot be polished like the rest of the surface. Have you considered soapstone? If I had a do over, I would go that route.

[Xene]

Re: Insulation blanket, ceramic insulating tape?

Soapstone. Hmm, I hadn't considered another material, I guess I was focused on this marble the entire time.

I'm considering cutting it myself. Anyone (obviously not professional stone cutters) out there do their own slab cutting? The sides are already cut to width on the marble chunk I have, I have to just square up the bottom --- and create a slight arch on one side, which I would need to buff with a grinder a bit to give it a nice edge. If I go that route, I don't really have any money in it, so if it broke with time, I could live with replacing it.

Another question, there is a lot of limestone in this area, could it be used? Any reason sandstone is a better material?

Thanks!

[Les]

Re: Insulation blanket, ceramic insulating tape?

Another question, there is a lot of limestone in this area, could it be used? Any reason sandstone is a better material?

I'm not a brick / rock guy but I would think that either limestone or sandstone would be too soft. Apparently soapstone can handle the heat and it will not soak up the greases that WILL drip as you are cooking meals. Pizza was never a problem but when I started using the Tuscan grill for steaks - messy!

[Xene]

Re: Insulation blanket, ceramic insulating tape?

Oh thanks Les, I meant to say soapstone, not sandstone. Ah, grease..of course - good point.

[dvm]

Re: Insulation blanket, ceramic insulating tape?

Granite can spall from heat as well. I just found out the hard way. I cut a piece for my garden window with a dry blade. I was just told yesterday that it cannot be polished like the rest of the surface. Have you considered soapstone? If I had a do over, I would go that route.

Is the problem that the dry blade "damaged the stone" so now it can't be finished? I know that granite CAN be polished to a smooth, shiny finish after cutting with a wet saw. (BTW a "skill saw plugged into a GFI with a diamond bade and low pressure sprinkler systems drip of water onto the blade mimics a "wet saw" very nicely). We put granite counters in the kitchen a few years back - this place had great prices (delivered)! and all the needed supplies Do It Yourself Granite Countertops - GRANITE COUNTERTOPS - Granite Countertop - Granite Tops - Granite Top - Granite Kitchen Countertops - Granite Counters Their polishing pads work great. I am going to try then on concrete next!
dvm