Max crawl space wall height

[Bammer25]

Trying to figure out the best route and most economical route for a steep slope cabin. The builder is getting beat up with buying loads and loads of gravel to fill up under basement slabs on steep slopes. I mentioned he could do a crawl space and lose the slab.

How high is too high for a masonry block wall generally? I typically do hand calcs for 99 percent of this residential stuff, but when I get into something a little top heavy like this I worry I’m not giving stability a good enough look.

 

[phamENG]

I think the slenderness ratio limit for masonry is somewhere in the h/27 region? So an 8" reinforced CMU wall can be about 18'. That's pushing it, but you can go pretty high. Narrow down your design from there - greater reinforcing, greater thickness, buttresses, etc. If I get a vote, I think you should bring back flying buttresses.

 

[phamENG]

Another thing to look at would be the residential code, chapter 6. They give height limits and reinforcing requirements for prescriptive masonry walls.