2x8 Forms for Hearth Concrete Pour - Wood-Fired Oven Build - June 2024

Busy week with the pizza oven.  First, the bottom trays and supports were put in-place.   Then, I cut, bent and placed some rebar into the top of the stand - via the bond beam blocks.  I also cut most of the grid of rebar.   That meant that I could move-on to creating the hearth forms.  I used 1/2" trays and I'd like the hearth to be 4" or so thick, so that means I need 4.5" of height on-top of the stand.  Because of the Bond Beam blocks and their openings, I also need the forms to cover 1.5" of the stand.  That's 6" of form - which means I can't use a 2x6, but had to upgrade to 2x8's.

I cut the 2x8's to length, then affixed a 2x4 to the face of them to stiffen them - and prevent bowing.  I used various pieces of lumber to create legs that were just a tiny bit short.  I put the forms together, stood-it-up on the legs and then shimmed in one side for the final height.  

Moving around the stand, I leveled up each side using shims to get the top of this heart dead-solid-level.  

Below are a few photos showing the hearth forms.  

I used some heavy-duty construction fasteners (lag bolt replacements) to connect the sides.  

When I was done, I was able to put to levels on the forms - one each direction.  

And, it is right-on-the-bubble.  Level all the way around.

The remaining tasks for the hearth include:  installing drainage pipes, wiring the sides (to prevent bowing), cut, wire and lift the rebar grid and fill the remaining cores with sand.