Laying Floor Bricks On A Bed Of ....

[Hendo]

I'm curious about two issues:

1. What is the reasoning behind the recommendation of 50% sand with the fireclay? I used 100% dry fireclay, as I found the stuff flowed much better when I plonked a brick down, and in fact the sand seemed to inhibit this 'flow', which ultimately affected the level of each brick and left voids underneath it.
2. If using the material(s) dry, what is the purpose of wetting the floor after laying the bricks? Aren't we just trying to create a level cooking floor?

Paul.

[asudavew]

I think it is to get the floor to set..........and not move.

But I am not positive about it.

[wlively]

That part did not make sense to me either.

I went ahead and used the HeatStop mortar to bed my floor. My reasoning was; the wet mortar made easy work of laying down the bricks and tapping level, I wanted the floor to act like one homogenous piece both mechanically and thermally, and I didn't worry about a slip plane because my floor sits on top of Insblock 19 insulation board.

[DrakeRemoray]

I am not sure about the sand mix, but the idea with the fireclay in general as as opposed to heat stop is that you could theoretically remove and replace a cracked hearth brick. Has anyone ever done that?

Drake

[waynebergman]

If using just fireclay did you use a trowel to spread things out? I am getting close to this part of the project myself so wondering about also what happens after firing up oven does this fireclay set up at all or is it going to stay in this state for a long time so bricks can be removed or replaced?...wayne

[DrakeRemoray]

I used a notched tile setters trowel. It does setup, but it does not adhere like mortar, just gets hard...

[nissanneill]

Having gone through the exercise, I'll throw my hat into the ring.
Hi Paul.
After building the soldier course and another 2.8 courses of bricks before the mortar mix ran out, I laid my hearth onto the quite level and flat vermiculite hearth. There was a few bricks that were a little lower than most so whilst reasonably accessible, I carefully lifted them out and put in the bottom a hand full of plain fireclay carefully levelling it with a paint spatular. The same brand as Paul has which is the consistency of portland cement powder. I then replaced the brick and tapped it down firmly. If still a little low, I repeated the exercise until it was level with the others. I can't ever see a need, BUT if I ever need to replace a brick, I can simply using a couple of thin bladed spatulars, wriggle the brick out OR drill a hile in it and screw in a plug/handle, lift it out and replace it.
I took the advice from the forum readings not to cement of permanently fix the bricks in.
Really, when you think about what you are doing here and where it is located, (below your heat sink hearth), you could use anything, even fine sand or cement powder to do the same thing.

Neill

[wlively]

Removing a cracked brick is understandable and am not trying to change anyone's mind. But, what are the odds of a hearth brick cracking, especially if it is supported evenly? I figure, pretty darn high. And let's say you win the lottery, so to speak, and get a hairline crack. The floor is full of cracks (seams) already, the cracked brick has no place to go, and the crack is most likely to be smaller than the seam.

My thinking was the thermal uniformity far outweighed any concerns of cracking.

[asudavew]

Originally Posted by wlively

Removing a cracked brick is understandable and am not trying to change anyone's mind. But, what are the odds of a hearth brick cracking, especially if it is supported evenly? I figure, pretty darn high. And let's say you win the lottery, so to speak, and get a hairline crack. The floor is full of cracks (seams) already, the cracked brick has no place to go, and the crack is most likely to be smaller than the seam.

My thinking was the thermal uniformity far outweighed any concerns of cracking.

I think I shall do the same.