It is difficult in any specification for flatness and levelness to avoid stating limits which must be achieved in construction. Even with the best construction techniques the required specification in free movement areas may not be fully achieved at a few points which represent a small percentage of the overall area. A common-sense approach might be taken as to whether minor deviations from the specified limits will be acceptable for the particular usage of the floor.
With only very few small discrepancies in a free movement area it is most likely that the floor surface will still be acceptable for the intended use. This is particularly true if the chosen flatness criterion is close to that in a lower classification. For example, if the racking height is, say, 8.5 m, the FM2 specification would naturally be chosen. If a few discrepancies on limits to FM2 are found, the fact that the 8.5 m criterion is close to the upper stacking height limit in the lower classification FM3 might allow a building owner and his advisor to accept a small amount of discrepancies to the limits specified.