Curing of Masonry Walls Question

[Berniedog]

I designed a 18'-0" high, 12" masonry wall. The inside is protected from the elements and the outside is not (Michigan -45 degrees +-). How long should it cure before placing roof joists on them?

 

[tolchijb]

Depends on the load and the strength of the grout. Masonry code requires 2000 psi grout but in the Cincinnati area I find we usually get 3000 psi grout. I would check the capacity with full dead and 3/4 of the live and wind (normal load combinations) to determine what would be required. I would not expect to need more than 3 to 7 days if you are getting 3000 psi grout. Chances are with 12" CMU the face shell will handle the gravity loads. Just be wary of the wind, which may still work as a 12" unreinforced gravity wall anyway if it is reinforced as an intermediate reinforced shear wall.