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.
Dipstick floor flatness.
F numbers provide architects and contractors a method of determining the flatness and levelness of a concrete floor slab.
Floor pavement profiler dipstick is the trade name of a profiling device manufactured by face construction technologies of norfolk virginia usa.
It s been 45 years since the face companies started developing what became modern concrete floor flatness levelness technology.
Testing labs building owners developers contractors universities research institutions and government agencies on six continents choose the dipstick because it produces the most accurate and repeatable flatness levelness data period.
The astm that directs how the ff and fl values are to be collected and calculated is astm e1155 standard test method for determining ff floor flatness and fl floor levelness numbers ref.
Dipstick was selected for the construction of the world s tallest building and to measure the flattest and most level superflat slab ever constructed.