I have a ton of brush that I used to burn, but I recently bought a chipper/shredder and want a spot to compost it along with grass clippings and greens. I also have 3 tons of CMUs that are just sitting here, removed from an ugly garden fence.
I want to make a 3 walled container for the compost, sort of like you'd see at a gravel yard. The back wall the tallest, and the other sides slanted down. I'll likely push the compost against the back wall, then when I mix up the compost, I'll just rake it flat and shovel it back into the back.
What's the laziest way I can build this with what I already have so that it doesn't fall over in 5 years or develop other issues?
I was thinking I want to do a 10 inch gravel footing and dry stack the CMUs. Maybe I'll fill a few with concrete, but that would require mixing concrete - maybe I'd rather fill them with really coarse gravel. I'll likely cut some of the CMU's diagonally with a diamond grinder so I can get a nice straight taper down and cover the CMUs with some cap blocks.
I don't know about mortar, because the CMUs are dirty. I don't know if it'll stick, and I don't know about how long it would take to clean them. I suppose kissing them with a grinding wheel would do the trick if it comes down to it, but I don't really feel like learning how to mortar anything either.