How To Measure Floor Flatness And Levelness

History of concrete floor flatness and floor levelness.

How to measure floor flatness and levelness.

Iirc the specification was that there should be no deviation greater than 1 16 inch per 10 feet of floor space. Fl tells you to what degree the surface of the slab approaches its design inclination often horizontal. To measure levelness use the differences z in elevation between two points that are 10 feet apart. Industry expert allen face is the creator of the f number system as well as the inventor of several measurement instruments and a principal inventor of superflat floor technology.

Levelness indicates the slope or tilt of a slab. Concrete slabs can be described in terms of flatness and levelness. To quantify floor flatness using f numbers you begin by measuring the elevation differences d between points on the floor that are 1 foot apart along a straight line. Homeowners will sometimes take a regular hose put a clear 2 foot plastic hose on each end and use it to measure the levelness at different locations.

The higher the f number the flatter or more level the floor. Reading up on installing laminate flooring i came across the warning that the floors must be flat for proper installation and use. Traditionally concrete floors were specified to have a deviation of less than 1 8 over 10 feet. This is where f numbers come into play.

F numbers were developed in the 1980s to provide a systematic quantitative way to indicate the flatness and levelness of a concrete floor. Not necessarily level but flat. Civil engineers and companies that specialize in oce surveys and documentation of floor levelness and elevations are often called upon when serious problems develop or if there is litigation. Levelness is measured in a similar way to flatness.

This was measured by laying a 10 foot straightedge on the finished floor and measuring the greatest gap below the straightedge. Flatness can be thought of as smoothness how bumpy or smooth the slab is. Levelness how closely the floor conforms to the specified slope and flatness how much the surface deviates from a two dimensional plane have become important specifications in construction. Levelness on the other hand is the average change in elevation over a longer distance for example inch in 12 feet.

This method worked quite well for decades. Some of the industry misconceptions for floor flatness and levelness are the following. There are two types of f numbers which measure floor flatness and levelness respectively. Flatness is a measure of how bumpy the floor s finished surface is.