Concrete Floor Flat Vs Level

The ff30 fl20 floor on the left is a moderately flat random traffic floor tolerance.

Concrete floor flat vs level.

Concrete floor slab flatness and levelness traditionally allowable tolerances of concrete floor slabs were determined by checking the slab surface with a 10 foot straightedge. Depending on where the measurement was made the slab may pass or fail the specified. When you look directly down at the floor it will appear somewhat hazy with little if any clarity or reflection. Level 1 flat a level 1 ground polish usually can be obtained by stopping below the100 grit resin bond.

Actually the floor must be flat which allows for minor variations in the level. F numbers were developed in the 1980s to provide a systematic quantitative way to indicate the flatness and levelness of a concrete floor. The higher the number the more flat and level the floor. The misconception is that a concrete subfloor must be completely level to install hardwood.

It spreads across uneven slabs filling in low spots as it creates a new level surface. The higher the f number the flatter or more level the floor. If you plan on leveling a concrete floor you can do so with relative ease by using a leveling compound. The special fmin system of tolerance definition and measurement requires that any defects in excess of the maximum allowable variation be.

As an example it may be expressed at f min l 85 f min t 100 l longitudinal. Level 2 satin a level 2 honed polish is obtained by stopping at the 400 grit resin bond producing a low sheen finish. The ff117 fl110 floor profile on the right exhibits the typical flatness levelness of a super flat floor. Floor flatness levelnessone of the things that distinguishes a high tolerance floor is its f number requirement.

The fallacy of the straightedge method was the location of the measurement. F numbers provide architects and contractors a method of determining the flatness and levelness of a concrete floor slab. Use this self leveling concrete for mak. Aci 302 1r 04 guide for concrete floor and slab construction american concrete institute www.

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. The primary reason for developing the f min system was to quantify the threshold of mast sway for preventing lift truck payload racking strikes and analyze the bumpiness of vna floors.