Practice Test Geeks(ACI) AccessData Certified Investigator Practice Test
← All ACI Flashcard Decks

Floor Flatness & Levelness (FF/FL Numbers) Flashcards

7 cards from real ACI practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.

Read the first 7 Floor Flatness & Levelness (FF/FL Numbers) flashcards as text

  1. What do FF and FL numbers measure in concrete slabs?

    Answer: FF measures local surface waviness; FL measures overall slope relative to a horizontal datum

    FF (floor flatness) measures local curvature and waviness of the surface, while FL (floor levelness) measures how level the floor is relative to a horizontal datum.

  2. What does a higher FF or FL number indicate about a concrete floor?

    Answer: A flatter and more level floor with smaller deviations

    F-numbers are inversely related to surface deviation; higher numbers indicate smaller deviations and therefore better flatness and levelness.

  3. Which ACI document includes F-number tolerances for floor flatness and levelness?

    Answer: ACI 117

    ACI 117, 'Specification for Tolerances for Concrete Construction and Materials,' includes F-number tolerances for floor flatness and levelness.

  4. What instrument is most commonly used to measure floor flatness F-numbers per ASTM E1155?

    Answer: Dipstick profiler

    The dipstick profiler is the standard instrument used to measure floor elevation differences for calculating F-numbers per ASTM E1155.

  5. What minimum FF number is typically specified for superflat floors used in very narrow aisle (VNA) warehouses?

    Answer: FF 100

    Superflat floors for very narrow aisle (VNA) forklifts typically require FF 100 or higher to ensure safe equipment operation at height.

  6. The F-number system was developed primarily to replace which older floor flatness measurement method?

    Answer: The 10-foot straightedge method

    The F-number system replaced the traditional 10-foot straightedge method, providing a more objective and statistically meaningful measurement of floor flatness and levelness.

  7. Who is credited with developing the F-number floor flatness and levelness system?

    Answer: Allen Face

    Allen Face developed the F-number system in the 1980s, which was subsequently adopted by ACI and ASTM as the standard method for measuring floor flatness and levelness.