Title:
Concrete Q&A: Understanding F-number Specification Compliance
Author(s):
Publication:
Concrete International
Volume:
48
Issue:
8
Appears on pages(s):
61-64
Keywords:
F-number, flatness, minimal local values (MLV), testing
DOI:
Date:
8/1/2026
Abstract:
This article assesses the concrete contractor’s obligation when the specified overall F-number is not achieved. The specified overall F-number does not control the quality of the worst portions of the floor. Instead, subdividing a large slab into multiple test sections allows individual areas to be evaluated independently. If one or more test sections fail to meet the minimum local values, only those deficient areas require remediation.
Related References:
1. ACI Committee 302, “Guide to Concrete Floor and Slab Construction (ACI PRC-302.1-15),” American Concrete Institute, Farmington Hills, MI, 2015, 76 pp.
2. ACI Committee 117, “Commentary on Standard Specifications for Tolerances for Concrete Construction and Materials (ACI 117R-90),” American Concrete Institute, Farmington Hills, MI, 1990, 11 pp.
3. ASTM F710-22, “Standard Practice for Preparing Concrete Floors to Receive Resilient Flooring,” ASTM International, West Conshohocken, PA, 2022, 10 pp. doi: 10.1520/F0710-22
4. Face Construction Technologies, “Processing Data,” Chapter 5, Norfolk, VA, Aug. 2022, 32 pp.
5. ASTM E1155/E1155M-23, “Standard Test Method for Determining FF Floor Flatness and FL Floor Levelness Numbers,” ASTM International, West Conshohocken, PA, 2022, 9 pp. doi: 10.1520/E1155_E1155M-23