Let’s face it, callbacks are a killer. You finish a flooring job, it looks great, the client signs off, but months later you get that
Floor performance starts with the slab—and slab quality starts with flatness and levelness tolerances. Whether you’re managing a commercial build or preparing to install high-performance
FF and FL numbers govern whether a concrete floor is acceptable for warehouses, hospitals, and retail spaces. This guide explains what the standards require — and what happens when you fail.
Technical Summary This document outlines a comprehensive methodology for conducting floor flatness (FF) and floor levelness (FL) testing in compliance with ASTM E1155. It details