All framing is placed 2″ beyond the heater footprint to meet clearance requirement. Only the subfloor bridges across that clearance (since it is a membrane that can dissipate heat and is necessary practically in construction).
Although pink board was used in this build, we strongly recommend 2″ Foil Faced Rock Wool Bats for that location. The insulation doubles as formwork for the slab. The extra vertical block columns are simply to support the cement board form work for the slab above.
This is so great! The pictures really show that you know what you’re doing, and it’s helpful to see product recommendations like Foil Faced Rock Wool and Skamol SuperIsol over silicate board.
You can see because of all the supports in the block work that the greatest span is not much more than 12”. While the slab could be thicker and have less supports, I find that it is necessary in closed foundations to temporarily support the cement board that forms the bottom of the slab to ensure it does not deform during the pour and, therefore, the spans are rarely very big.
Is this for the hybrid you were recently going to build? I’m also seeing an outside air duct, yes? Will be excited to hear what you’ve learned in this build. My stove foundation is complete but I am at the materials-sourcing phase.
Hi Max. Are you filling those cmu blocks with concrete as you build up? Looks like you have holes cut out of board where concrete goes in when you’re pouring slab. Thanks for the information
@Tom, I am not filling all of the cmu blocks as I go but rather defining specific reenforced “posts” which you have identified which have rebar stubbed into the footing slab and make for a continuous reenforced structure with the subfloor slab.
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