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Fun Fact Friday: Floor Flatness / Levelness Testing

By October 26, 2018No Comments2 min read

DID YOU KNOW? #funfactfriday

Floor Flatness / Levelness Testing

One service that Encorus’s Civil Testing Group provides is the measurement of floor flatness and levelness. Floor flatness, known as FF, measures the bumpiness of the floor surface. Floor levelness, FL, measures the slope of the floor surface. Oftentimes, variations to floor flatness and levelness cannot be detected with a visual observation alone, so professionals use a floor flatness/levelness testing method to measure those variations.

The testing process begins with marking straight lines on the floor surface in various locations. Along each line, point elevations are recorded at one-foot intervals. The differences between each contiguous elevation point are calculated, and then a straight-line approximation is created. This approximation is analyzed and compared with visual observations of the floor.

Calculations are made for the difference between all contiguous elevation difference measurements for the one-foot intervals, and the differences between points separated by 10 feet. The resulting value is a flatness and levelness profile for the floor surface. This profile can then be used to determine whether or not the surface complies with flatness and levelness tolerance specified in the construction documents, detect potential effects that different construction techniques would have on the floor surface profile, and identify any faults in the floor surface, such as curling and deflection.

Based on the floor profile calculations, floor surfaces are defined as follows:
• FF25 / FL20 – moderately flat
• FF35 / FL25 – flat
• FF45 / FL35 – very flat
• FF60 / FL40 – super flat

Spaces with specific uses and regular use of more advanced technology require a flatter and more level floor. For example, general office space might require a moderately flat floor, while an ice rink requires a very flat floor. Movie and television studios, because of the specialized equipment which must traverse the floor surface smoothly, require a super flat rating.

If you require floor flatness/levelness testing services, contact Jeremy Lake at (716) 592-3980 x133 or