Floor Flatness 30

Floor flatness levelnessone of the things that distinguishes a high tolerance floor is its f number requirement.

Floor flatness 30.

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. The more bumps there are the lower the ff number will be and the more difficult it will be for a polished concrete floor to have a uniform appearance. Concrete contractor pours the concrete and finishes it to the specified floor flatness requirement as stated in aci 117 specification for tolerances for concrete construction and materials the f f must be measured within 72 hours of the concrete pour. The higher the f number the flatter or more level the floor.

The ff floor flatness measurement reads the bumps highs and lows in the slab and higher numbers are better. When bidding a new construction project reading the 03 30 00 cast in. 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. What does a specification for a floor flatness of 1 8 inch in 10 feet equal in f numbers.

The tool provides an accuracy of 1 8 inch at 30 feet and laser line visibility of 30 feet. Concrete strengths rebar average rebar weights welded wire mesh pan slabs slab flatness and f numbers. However it is commonly known that concrete will continue to undergo change e g. They describe a concrete slab s flatness ff and.

Since it was introduced in the 1970s f numbers have proven to be useful in measuring and improving concrete floor flatness and levelness. With modern finishing equipment achieving overall floor. 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. 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.

F numbers provide architects and contractors a method of determining the flatness and levelness of a concrete floor slab. The working range of the laser is up to 65 feet when being operated with the remote control.