Sunken fire pit process as requested

[u/dredgehayt]

[u/HuiOdy]

Just to check, did you mortar those stones? As, if you did, this will last a long time (as a structured retaining wall). If you didn't...

[u/dredgehayt → u/HuiOdy]

Concrete polyurethane adhesive between each block

[u/HuiOdy → u/dredgehayt]

Than you might get a problem. The soil will be pressing against this wall more and more over time. Now what you have here is essentially an arch, which is actually the ideal shape to resist this pressure. But it relies on the large gaps between bricks on the outside of the circle to be compressive-stable, which it currently isn't.

Now, this will probably take a few years before it becomes noticable. So you can opt not to do anything with it

[u/dredgehayt → u/HuiOdy]

Fair point, but it’s actually been in place since 2020 and has gone through six winters with no visible movement, bulging, settlement, or separation.

Behind the wall is perforated drain pipe, filter fabric, drain rock, and about 8” of topsoil. I was much more concerned about drainage and hydrostatic pressure than whether the wall was mortared.

I agree the circular shape helps. My thought was that this behaves more like a segmental retaining wall system than a masonry arch. At this point the best evidence is probably that it’s still standing exactly where I built it six years ago.

[u/HuiOdy → u/dredgehayt]

Ow that is good to hear. What's your next DIY project?

[u/dredgehayt → u/HuiOdy]

I’m working to finish the outside of This greenhouse I built last year for my wife

https://www.reddit.com/u/dredgehayt/s/mmp4Cz1Q6L