Did I just ruin my pizza oven hearth?

[Crewton]

So now I think I’ve gone and done it, help!!! Several times in clean up while building the arch, I’ve hosed down with water where mortar has dropped. I haven’t hosed down the actual place I’ve been mortaring, I’m not that dumb. However, several times I’ve hosed down the hearth where the herringbone design is.

I was just poking around reading posts today for fun and saw this:

“Yes, this is when you need to start keeping water out of the sand underneath your firebrick. Moisture will eventually be wicked away by the concrete frame (which—defying all appearances—is porous and will suck up water), but that takes time and will affect the performance of your hearth until it happens.”

So, have I just ruined everything because that firebrick and sand had plenty of water on it from the hose.

[bikerbudmatt]

You have not ruined everything—you’re fine. The sand underneath the firebrick is now very wet and will take a while to dry out. As the post you ran across said, some will eventually wick out, though that will be a slow process because it will not go directly down through the insulating layer but rather to the sides and to the regular brick framing the hearth. Some will evaporate back up through the herringbone joints. And eventually, all of it will bake out.

If you want to speed that up a bit, I would suggest you modify your initial firings very carefully and deliberately in this manner: do firings 1, 2, and 3 as recommended. For firings 4, 5, and 6, build the fire as recommended, earlier in the day, and then add the same amount of wood as you did to start the fire. The goal is not to make the fire any hotter, but to allow more heat to soak into the hearth over a longer period of time.

I must emphasize that you do not want a hotter fire, but a longer fire. You still need to make sure you are curing the joints in the barrel arch in a slow and progressive manner.

I started this reply by saying the sand underneath is very wet. That does not mean the hearth will fail to heat up, but it just won’t be as thorough as it should be. My opinion is that no permanent damage was done.

Keep on building, and sharing some photos would be great when you have a chance!