They describe a concrete slab s flatness ff and.
Floor flatness 30.
For example an ff 30 fl 24 floor is exactly twice as flat and twice as level as an ff 15 fl 12 floor 03 guidelines for f number substrate concrete floor finish tolerances under resilient floors.
Although there are no direct equivalents between f numbers and straightedge tolerances aci 302 construction of concrete floors and slabs gives the following table of approximate values.
The working range of the laser is up to 65 feet when being operated with the remote control.
The ff floor flatness measurement reads the bumps highs and lows in the slab and higher numbers are better.
With modern finishing equipment achieving overall floor.
Since it was introduced in the 1970s f numbers have proven to be useful in measuring and improving concrete floor flatness and levelness.
The scale is linear so that relative flatness levelness of two different floors will be in proportion to the ratio of their f numbers.
The higher the f number the flatter or more level the floor.
Floor flatness levelnessone of the things that distinguishes a high tolerance floor is its f number requirement.
F numbers were developed in the 1980s to provide a systematic quantitative way to indicate the flatness and levelness of a concrete floor.
Concrete strengths rebar average rebar weights welded wire mesh pan slabs slab flatness and f numbers.
F numbers provide architects and contractors a method of determining the flatness and levelness of a concrete floor slab.
What does a specification for a floor flatness of 1 8 inch in 10 feet equal in f numbers.
They are calculated using the standards set forth in astm e1155 which is the standard test method for determining f f floor flatness and f l floor levelness numbers the american concrete institute indicates acceptable ranges for flatness and levelness in aci 302 1 guide.
However it is commonly known that concrete will continue to undergo change e g.
The tool provides an accuracy of 1 8 inch at 30 feet and laser line visibility of 30 feet.
The gsl 2 provides high accuracy for detecting uneven spots by checking the floor surface in a radius of up to 65 feet in a matter of minutes.
Concrete slab flatness slab flatness the degree of a slab s flatness is expressed by two numbers the ff and the fl together these are the f numbers they are the face floor profile numbers developed by allen face from 1978 to 1987.