Couple of Wood-Fired Pizza Oven Hearth Construction Tips Via YouTube - May 2024

Last week, I posted my latest update on our backyard pizza oven build where I mortared in the first course of the cinderblock stand.  I'm on my way this week to swap out some of the blocks and to pick up the rest of the angle iron so I can drystack the rest of the stand.  At risk of getting things out of order, I'm going to talk a little bit about the suspended hearth.  That hearth sits ON TOP of the stand.  It is reinforced concrete that is framed up with a 2x6.  That means - at the VERY MOST, the hearth is 5.5" thick.  But, because you overlap the forms with the block stand, you lose about an inch - so it becomes something like 4.5" thick.  

I'm thinking about the hearth and the materials required as I run to the hardware store and I found a bunch tips that I'm going to use in my hearth build via the Blood Sweat and Beers YouTube channel - this video where he walks through his reinforced hearth forms and setup.   I thought it was worth documenting here in my pizza oven build process so I remember them when the time comes.

There are five things that jumped out to me in his hearth build - some of which are called out in this screenshot below (source is his video):

Those five tips that jumped out to me (that are worth remembering) are:

1.  Electrical conduit. He ran a pipe up for future electrical into the enclosure.  

2.  He used Hardibacker board and is planning on leaving it in place.

3.  He used 2x4 stiffeners around his forms.

4.  He used a concrete screw to attach the forms (in the center) to the stand.

5.  He filled every-other-cavity in the stand with concrete and rebar.  And he filled the remaining ones with sand to keep the concrete from dropping down in those.  

Five-for-five.  All clever ideas that I'm going to utilize when I get to my hearth.

One thing that he didn't include (that I plan on using) is/are weep holes in the hearth via 1/2" pvc pipe.  He got to weep holes in a later video, but I'm going to use the pipe from jumpstreet.

He talked about his hearth using just about 1600 pounds of concrete - twenty 80# bags.  I just popped my dimensions into a concrete estimating tool and I'm coming up close to that.  I rounded up an inch each direction and it is telling me I need 1500 lbs of concrete or 25.25 60# bags.  I initially bought 80 bags and used 46 for my foundation slab leaving me with 34.  What isn't accounted for here is the space in the bond-beam blocks.  That will add some volume, so I'm thinking I need to grab 5-6 addtional bags (just in case).  See below for the estimate:

The guy at Blood Sweat and Beers built his using a pre-cast oven for his build, but if you are doing a kit or piecing the dome together with firebrick, he has a number of videos that are very much worth watching if you're thinking about taking on a wood-fired oven build project.  He shows how he built his cinderblock stand, how he used some cheap mosaic tiles to lift up the floor insulation and keep it from getting wet and most-recently has a post-mortem on his finished pizza oven landing (the front counter part).  All good stuff and worth the time.

Now...I need to secure the insulation so I know how tall to make my stand.