How precisely level does the herringbone base have to be? How much should I obsess over it? Is a mm or 2mm worth obsessing over?
Sorry in advance…I would do my level best, and then move on.
It sounds like you’re talking about the entire hearth sloping a bit in one direction. If that’s the case, I would obsess. Everything up to this point in your build should have been level, but if you were off by that mm or so you’re still okay.
But the hearth is the first critical surface. You’ll be resting pans and sheets with hot oil on it (pizza will never get old, but your horizons will expand!). If you’re not level now, it will be reflected later, and this is your chance to get it right.
It is worth pulling out your herringbone brick and getting that sand perfectly level. It is critical if the issue is little hills in the sand itself, raising a brick or two, or making a “mound” in the center.
If the issue is a single brick rising above the rest, or sinking in, that’s easily adjusted by pulling that brick and adjusting the sand underneath.
I do encourage you not to move forward until you have a level hearth, all bricks flush at the top, and a centered bubble on your 4 foot level side to side and front to back.
Pro tip: if the entire hearth is a mm or 2 above or below the brick frame, don’t worry about that. The first row of bricks in the arch will cover three sides of the frame, and it’s okay if the lip at the oven mouth is a bit above or below. (I’m still talking no more than that small increment—if it’s more or less than that, you should still fix the entire hearth before proceeding.)
Good luck and keep us posted on your progress!
How does this look. It’s level. I tend to be a little OCD. I want to make sure I’m not over doing it. Is this good? Or does it have to be perfect.
That looks great! As discussed previously the edge bricks will be covered by the first course of arch brick. I think this looks very good indeed, and I pronounce it perfect.
Thanks for helping to “walk me through” this. I appreciate your input and feedback.