Cinder block arch

[Altie22]

Im making a cinder block arch for 2x4 Flat pan from smoky maple. Could i keep the bottom blocks sideways to make a better draft for the fire and just keep door closed?

[ecolbeck]

Do you mean a bottom block on the sides or the front? I would keep the sides closed off. A sideways block in the front would be useful, especially if the fire is raised up on grates. Have fun!

[Big_Eddy]

Short answer - yes.
With a block arch, you want the front 20" - 24" to be nice and deep so that you can put a grate on the bottom to get air under the fire.
For the rest of the way back to the smoke stack, you only need 2-4" of space under the bottom of your pan.

If you place the lower row of block for the back half sideways, you would fill up the lower half of the space and move the flames closer to the bottom of the pan.
You could also toss sand, gravel, dirt, loose blocks or anything else into that space to fill it up.

Either way - by reducing the gap under the back half of your pans, you will increase the overall efficiency of your block arch.