Slab on Grade - Settlement Tolerance

[NBRY1]

Why do geotechnical engineers often not mention slab on grade settlements, since they are often independent of the building?
Is there an acceptable level of movement for slabs (total/differential)?

 

[r13]

Unlike footings, SOG does not support main building support elements that are settlement critical, especially differential settlement.
For well prepared subgrade, SOG might settle a negligible amount, if any, that usually is not noticeable. Uneven settlement likely will damage the slab, I don't think it is acceptable, and may require remedial action to correct the problem.

 

[oldestguy]

In my experience about the only time I would be concerned about possible excessive entitlement were when I knew the floor loading would be high and tolerance for differential movement or slope would be of concern. So then that topic was examined more thoroughly and recommendations made accordingly. Otherwise, no comment.

 

[Phil1934]

The National Wood Flooring Association recommendation for flatness of the substrate for an engineered hardwood floor installation is no more than 3⁄16 inch deflection or variance in the slab within any 10-foot radius of the floor.