Masonry Wall out of plane deflection limit
Masonry Wall out of plane deflection limit
(OP)
When designing masonry buildings ACI 530 states an out of plane deflection limit of 0.007*h which must include p-delta affects. The IBC states out of plane deflection for walls should be L/240 for brittle finishes. We have used 0.007*h in the past, but we are wondering if we should really be using L/240. for a 20'-0" wall height, it is a pretty large difference in deflection. L/240 = 1" 0.007*h = 1.68". Which is the correct deflection limitation? 1.68" seems like a lot in 20'-0".






RE: Masonry Wall out of plane deflection limit
Your deflection is governed only by ACI 530 unless the CMU has a plaster finish.
1.68" is a lot, but that is probably based on a load that the structure will never see. You don't want to know how much I allow wood stud walls to deflect.
RE: Masonry Wall out of plane deflection limit
If I used the L/240, would I still need to include p-delta affects?
RE: Masonry Wall out of plane deflection limit
RE: Masonry Wall out of plane deflection limit
I had one minor actual failure in CMU and it had nothing to do with this issue here.
RE: Masonry Wall out of plane deflection limit