The Fresh Loaf

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Door width = 1/2 hearth width?

Gadjowheaty's picture
Gadjowheaty

Door width = 1/2 hearth width?

Hi all,

A general enough question I thought it merited its own thread, as opposed to continuing off my other thread.  Mods, I deign to your judgment, of course.

So, in the interest of just getting going, I plan on putting together a mud oven, hearth dimensions tbd.

In the book Build Your Own Hearth Oven, they give a suggested door width of 1/2*hearth width; if the hearth is 22.5" wide, that would mean a door of 10.5" 

That seems really small to me.  I intend on bread baking almost entirely, with the occasional pizza.  The peel I use to off-load boules is itself 12" wide - wider than the above door.  

FWIW, this is just an entry-level oven, to get one up and running.  I only intend on a loaf or two, and if all goes well, will plan for a larger oven.  Just to learn the build and baking dynamics.  Likely, as suggested in the book, 22.5 wide or 10 bricks side-by-side (i.e., 2.25", or 10 bricks side by side for the width, and 2.5 bricks @ 9" end-to-end for the hearth length).  

If I go by the books' suggestion on the door width, I would need a bigger oven.  But I don't want a larger oven with just a loaf or two, as I know a full oven is a better oven. 

So - how do you guys calculate the door width?

 

Edit:  While here, might as well ask on firebrick sources.  With overage, I'll be looking at only 30-35 bricks.  I plan on medium duty, with layer underneath TBD.  Can anyone recommend their good source for direct purchase, and what specific bricks they went with?

Many thanks for your thoughts.

Paul

idaveindy's picture
idaveindy

give a suggested door width of 1/2*hearth width; if the hearth is 22.5" wide, that would mean a door of 10.5"

actually,  22.5 / 2 = 11.25.

I take it your fire bricks are 2.25 x 2.5" ? 

They do come in varying sizes, as far as I know.

And the door width does not have to be an integral number of bricks. You're allowed to cut them, AFAIK.

Gadjowheaty's picture
Gadjowheaty

Sorry, yeah, my mistake.  Bricks also come standard 2.25, not 2.5".  So, 10 across.  

The question on the door goes to how narrow one would be, if doing 1/2 the hearth width - can't fit my peel through the door, for one.  I presume the 1/2 dimension goes to draft dynamics, etc.?  I'd really like to know what it would do to keep a 22.5" x 22.5" oven, with a 16" door width, and 10" door height (.63*16", interior dome height).  I presume that messes up the proper draft?

Trying to save on building a large oven, as I don't expect to be baking more than a couple loaves at a time (and this first build is just a pilot build).

idaveindy's picture
idaveindy

What country are you in?  Your profile says Wisconsin.

Lowe's has this:

https://www.lowes.com/pd/Unbranded-Fire-Brick-Full-Size-2-5-in-x-4-5-in-x-9-in/5000270269

You can also put high temp mortar between the hearth bricks, no? Or do you lay them up without mortar?

If this is a temporary oven, lay them so the thickness top/bottom is 2.5", so you have 4.5 x 9" surface area.

Or am I picturing it wrong?

Gadjowheaty's picture
Gadjowheaty

Thanks Dave.  Yep, WI.  Thanks too on Lowe's.  In the past, not available to me, but will try (currently OOS).

The hearth bricks are laid w/o mortar, which is why you need crisp-edged bricks.  IIRC.

It's a temporary oven, but at least going by Allen Scott, he suggests 4" hearth thickness (and I've seen the same around the web).  That said, plenty of plans I've seen (incl. the earth oven book itself) indicate lining up edge-to-edge, so the faces are on top.  Probably overthinking this.  

idaveindy's picture
idaveindy

If you are going to disassemble this oven after a year, and re-use the fire bricks, and build the same size or bigger "permanent" oven, then I suppose it would not hurt to over-engineer or over-specify the fire bricks, since they will be recovered and re-used.  

It sounds like a cool project. 

Please take and share as many "in process" photos as you can.  The rest of us duffers can share your adventure vicariously.

idaveindy's picture
idaveindy

I also suppose a new smaller peel would be cheaper than another row and column of brick.

(ok, I finally "see" the dimensions of the bricks you plan on using.)

 

Gadjowheaty's picture
Gadjowheaty

True there!  I use the peel not so much for pizzas but for boules, with my largest going to a miche at 2 kgs and 14" in diameter - so would need a larger door to begin with, just to get my boules through.  Just wondering what the reasoning is on this "1/2 hearth width" figure for the door width, and if there's something one could do to broaden the door big enough, without having to build a way-oversized oven (interestingly, it's how a cheese cave works best, too - loaded fully).

 

Just to make it easy, 10x3 bricks for 22.5" wide x 27" long hearth.  How does this sound, if not baking dozens of loaves daily?  A reasonable hearth plan, or too big (or small!)?