Gaps in floor - should or shouldn't ...

[dvonk]

... I fill them with dry mortar and then pour the water over it?

The problem is (and nobody - I stress - nobody! - didn't tell me that all the bricks have different size and it's much more better to spend the whole day by drinking beer instead of...) that finally I've got some gaps between bricks pretty big - around 3-4 mm (not only the size of bricks differs, but they are also not strict parallelepiped, so it was challenging, by the way, stamp on one side of each brick doesn't allow to flip it over! damn bricks!!!).

And now I'm thinking of using dry mortar to fix that (it will also, I guess, give to masonry additional strength). Is is good or I'd better leave the gaps and allow them to be filled by ash?

I've set up the with mortar of fireclay and chamotte, no concrete at all. Is it OK?

[Frances]

Hey dvonk,

I think often when you don't get an answer to a question its either because it doesn't matter much either way OR because its something new and no body knows the answer yet. Took me while to work that one out

I think with your floor you could go either way, but personally I'd leave the gaps to be filled with ash. Any other opinions on that one out there?

The mortar you mention at the end of your post... would that be the mortar for under the oven floor, or the mortar for building the dome? If its for under the floor its fine. If its for building the dome - well, that's basically what I used on my oven. And it works (so far... ). But it is a little bit unconventional.

By the way, your bricks on the floor may have been difficult to lay out, but they look great! I love the different colourings you have there.

[gjbingham]

I used the cuttings from the tile saw when cutting bricks for the dome to solve that problem. It didn't. The heating cycles caused the bricks to expand and the gaps reappeared eleswhere.

[dvonk]

Hi Frances,
Yes, its a high-heat mortar for building the dome. It's industrial one, suitable for lining the even the furnace.

[dvonk]

This mortar, as I know, bake during the firing (fire brick dust doesn't, as I understand), so, perhaps it wouldn't leave the gaps after several cycles - since it consist of the same ingredients as firebricks, it should give the same thermal expansion as bricks.
The most thing I want to achieve is to give the floor additional integrity, the gaps by themselves didn't worry me to much.

[gjbingham]

Hey dvonk. Give it a try. We all do what we think is right. The bricks need to be wet before adding mortar to the gaps. I'm guessing you'll need to really really wet down the floor. Then actually getting it down into the gaps sounds difficult, to say the least.

Too bad the bricks aren't uniform, huh? It would make the whole project a lot easier.

[dvonk]

I'm going to fill the gaps with dry mortar, then wet it. Otherwise I'll be not able to do that.
Yes, the bricks differ. But anyhow, I'll tappering them, so I'm expect not to have a real problem with that during dome construction.

[gjbingham]

Cool. Let us know how it goes. Other builders in the future may want to know how it worked.

Best regards.
George

[dvonk]

George
I was thinking it will be cool if somebody with experience tell me that it won't work before I try and learn

[Frances]

If anyone thought it was going to be a catastrophic mistake... they'd be sure to let you know. As is is, it'll be an interesting variation for future builders to consider.