Survey Practice in Facility Work

[Roadwork]

What's the consensus, it is common practice in facility (vertical) work to state elevations with negative values on design plans? I think not, but I'd like to hear what others have seen/done.

 

[JAE]

I've seen it numerous times - usually where the designer has noted a top of floor elevation on the plan sheet for each level. Then there is a global note that states that dimensions shown on the plan in the form of (-2 1/2") are top of steel elevations below or above the finished floor elevation given.

This is a handy way to communicate various top of steel elevations when they vary on a floor level. Usually this occurs due to joist seats, brick supports, etc.

 

[jechols]

I do it on almost every job. I usually refence the absolute floor elevation and then reference the various elements relative to the floor using plus or minus e.g. top of footing (-2'-0") or top of steel (-6").

j