Building Elevation Tolerance

[JAE]

Is there some understood tolerance for the final overall floor elevation when constructing a building's ground level floor?

I know there are ACI and other concrete specified tolerances for flatness and levelness, ACI 117, etc.

What I'm looking for, though, is the overall setting of a building's final floor elevation. ACI seems to only deal with the flatness levelness of the floor itself and not the global, overall elevation.

 

[BAretired]

I think it would vary according to the use and occupancy of the building. For most buildings, it wouldn't really matter if it was out by an inch or two because exterior grade can usually be modified to accommodate the floor elevation.

If there are special concerns about a particular floor having a close tolerance in overall elevation, it should likely be spelled out in the contract documents. This could be a concern in an LRT station where the rail elevation has been set and the floor has to be set relative to that. Or perhaps an addition to a process building where the new floor has to relate to existing.

BA

 

[dhengr]

JAE:
Maybe base your elevation tolerances on some construction surveyor’s standards of work, the precision level they are working to or can work to. But, that could vary also, as a function of the specs. or contract requirements they were working to. Certainly, they can set levels and elevations to a good degree of accuracy and certainty, but I suspect if a floor elevation is particularly important we should show this and a tolerance on our construction documents and refer it to some well defined bench mark, in the area.

AISC has some info. on tolerances in their Code of Standard Practice, and I believe I have seen some info. on tolerances for conc. formwork, but this subject kind of seemed to be a neglected area of building construction the last time I needed some info. Why has this not been codified at several different levels of building erection precision? Google ‘building erection tolerances,’ Amazon and others show several books on building tolerances which might give you some leads.

 

[dhengr]

Take a look at ACI 117-90.