F l specified overall value 25 minimum local value 18 c.
Ff 35 floor flatness.
Flat 35 25 very flat 45 35.
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.
F numbers provide architects and contractors a method of determining the flatness and levelness of a concrete floor slab.
F f 25 f l 20 moderately flat.
A self propelled laser guided screed can routinely create fl numbers of about 35 and higher.
F f f l numbers have the following floor flatness classifications.
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.
Flatness is a measure of how bumpy the floor s finished surface is.
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.
Ff fl numbers have the following floor flatness classifications.
It recommends that slabs to receive thin set flooring with moderate or heavy traffic have composite flatness and levelness of ff 35 fl 25.
A self propelled laser guided screed can routinely create f l numbers of about 35 and higher.
F f is measured as the curvature of the floor over a 2 foot interval.
The f f value is primarily a result of how good the finisher was at working the.
F f and f l tolerances shall be tested in accordance with astm e 1155.
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.
Minimum subfloor flatness using astm e1155 ff sof f or a 10 3m.
Concrete strengths rebar average rebar weights welded wire mesh pan slabs slab flatness and f numbers.
Ff25 fl20 moderately flat ff35.
F f this number is used to indicate the flatness of a random traffic floor.
Floor flatness variation from surface plane bumpiness f l floor levelness variation from horizontal plane pitch.
They describe a concrete slab s flatness ff and.
Actual overall f numbers shall be calculated using.
