Storm shelter addition 1

[TroyD]

An architect sent me this sketch of a proposed addition to an existing storm shelter. To support the pre-stressed plank roof above, I am proposing a 12" CMU bearing wall be added parallel to the existing exterior wall. (I don't want to add any axial or lateral load to the existing wall). I show a new footing "scabbed" on to the existing footing. I am familiar with the ICC 500 design requirements (250 mph wind speed). Are there any other recommendations for constructing two CMU walls next to each other? What is the appropriate method/spacing of tying together? Any advice is appreciated.

 

[r13]

I think you shall pay attention to the interface of the walls. Either grout it solid, or leave adequate air space to avoid condensation and relate problems.

 

[ChiefInspectorJ]

Consider differential settlement between the 2 walls. I think a gasket type system might work.