ypical values for floor flatnesslevelness

huangyhg

typical values for floor flatness/levelness
what values are reasonable for an office type floor, not a warehouse?  according to aci concrete knowledge center, ff = 20 and fl = 15 are "conventional numbers."  this would be equal to a 5/16" gap under a 10' straightedge, which seems excessive, but maybe that is typical.  i would like to hear what numbers you normally specify, and if they have been verified by a lab as actually achieved.  thanks for your feedback.
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ff=25 to 30, fl=18 to 20 will get in a reasonable range, somewhat near or slightly better than 1/4 under 10-ft. straightedge.
when you exceed these numbers, it requires more control in the placement and finishing process, that might not be worth the extra effort/cost, particularly for general office use.
the floor must be finished to some reasonable standard.  a deviation of 1/4" in ten feet has long been a specified standard, but in the last fifty years, i cannot recall anyone ever checking to see if the floor complies.  it is a good idea to have something in your spec just in case you get a really wild floor finish and the contractor wants to argue that it really is okay.
best regards,
ba
depends what type of flooring you are putting down. if its carpetting- i would think the lower values would be just fine.