UPDATE APRIL 1998

FLATNESS AND LEVELNESS

Flatness and levelness are terms increasingly utilized in recent years to specify finish criteria in concrete floor slab construction.

Flatness describes the magnitude of "waves" in a floor surface. Levelness refers to the relationship of the floor surface to a horizontal plane. ASTM E-1155 "Standard Test Method for Determining Floor Flatness and Levelness Using the ‘F-Number’ System (Inch-Pound Units)" describes the ‘F-Number’ system and a recommended measurement system.

The F-Number system assigns a numerical value for both flatness and levelness. A higher number indicated a flatter or more level floor surface. FF, referred to as the flatness F-Number, defines the maximum floor curvature allowed over a 24 inch (610 mm) length. FL, referred to as the levelness F-Number, defines the relative conformity of the floor surface to a horizontal plane over a 10 foot (3 m) distance.

Care should be taken when specifying floor systems using the F-Number system. Typically, F- values range from FF25 to FF40 for hardened floor systems to over FF100 for superflat floors which are sometimes required for high-bay, narrow aisle warehouse floor systems. Concrete compressive strength, finishing techniques and equipment, and curing methods significantly affect the finished product and vary depending upon the specified F-Number.

We enjoy our work with the architectural community, and appreciate your consideration. Should you wish to discuss the need for structural engineering services on your projects, please call at 570-823-9935. Thank You.

Connect with us!
   
 
Send mail to frontdesk@qproq.com with questions or comments about this web site.
Copyright © 2011 QproQ Engineering, Inc. All Rights Reserved.