Floor Bricks breaking

[fremen325]

I did a round of pizza and bread yesterday and noticed my peel kept catching on the floor of the oven. I left the door off last night so it would cool down faster and could see that the bricks have shifted upward and have cracked and started to crumble in places. We had a really wet winter and I am wondering if moisture got down into the sand layer between the fire bricks and insulating bricks. My plan is to pull the bad bricks out, check the sand layer to see what shifted, re-level, and put fresh fire brick back in. However, I suspect this will not be as easy as it sounds.

If anyone has suggestions on how to fix, I would appreciate them!

[SableSprings]

Definitely looks like you need provide a better "shelter from the storm" for the oven. It appears that your entry bricks absorbed water as well as your insulation below, so when you built a hot fire on them, the expanding steam expanded/cracked 'em. To replace the broken bricks, you can simply take a brick chisel and break one of those enough to start bringing out the pieces. You may be able to use a screwdriver to just pry up the already high pieces for removal. Looks like you've got three bricks up for replacement. After you inspect/repair/re-groove the leveling base sand/fireclay, you should be able to place the new bricks and tap them level...that's why the grooves are useful in the base sand/fireclay mix (just like laying tile).

After any weather (or overwintering) that might have gotten the oven "innards" wet, you want to avoid making your first season firing...a pizza fire. IMHO, it's worth doing a couple low level fires at the beginning (in essence, re-curing the oven) to be sure that the oven's been dried out internally and is ready to go for the season. Good luck and make sure to post back how the brick replacement process went.

[fremen325]

I was able to finally work on making the repair and found that it was not anything pushing up from below. Instead it looks like the firebrick surface failed and crumbled. It could still be a moisture issue but now I am less certain that was the cause. I had purchased the bricks from Adam Products here in Durham, NC. Now I am wondering if I should put new firebrick (same source) back down or try to come up with a different solution. A buddy of mine is a potter and thinks I should use cast refractory kiln shelves. Any advice/ opinions on how to proceed?

[SableSprings]

Since firebricks are used extensively for cooking floors in WFO on this site, I'm suspecting that these firebricks had gotten wet and were damaged when the oven was fired up (too rapid heating with moisture in the floor bricks..."exploding" steam caused breakage). I would put new firebricks back into position and do some slow & low fires around them, gradually moving in with the heat source (I think charcoal briquettes would be your best option to keep control & lower temps). You could also ask your buddy if he could use his kiln to slowly cure your replacement bricks before putting them back into place. Although you could cast refractory plates for the cooking floor, it seems to me that it would be more work than it's worth in your situation.

If you had a lot of moisture/water get into the floor base or bricks this winter, it is going to be a recurring problem. Many folks here (from wet/humid climates), do a series of low/slow fires to basically re-cure their ovens and remove water that's penetrated the oven over the winter/rainy season (or long periods between firings). The better your oven is protected from the elements, the less likely damage such as this will occur.

Hope that helps some and keep us up to date on your progress.

[rwiegand]

Not much to add, I'd replace the failing bricks and do curing fires as others have recommended to repair the current problem. However, my first priority would be to figure out how/why/where water is infiltrating and address that problem Your oven will never work very well if it is recurrently getting soaked.

Also, this is another good argument to not let your oven lie fallow. We made pizza all winter; snow and cold have little effect on the oven.

[fremen325]

I seated new bricks today and was able to get them fairly level and even. I still need to do a couple slow firings/curings to get the new bricks dried out but was happy to get this far! Thank you Sable Springs and Rwiegand for your feedback!!

[UtahBeehiver]

An angle grinder with a diamond cup will knock off the high points.which can catch the peel. Some people have been successful with a belt sander and course grit.

[mk e]

We sanded the floor in my oven flat with a 4" 100 grit diamond pad iirc...they are like $10 and leave a nice smooth finish.