Concrete Slab Flatness Tolerances Uk

Flatness and levelness tolerances.

Concrete slab flatness tolerances uk.

Table 12 10a extract from smd tgn online and bs 8204 gives three tolerances for floor flatness. However as shown in table 12 10a sr1 is not achievable on metal decking suspended floors. Specialist tolerances can be agreed between client designer and contractor. The higher the f number the flatter or more level the floor.

All points should be within 15mm from planned level. Fm tolerance concrete floors are surveyed according to flatness and levelness. 5 it is not possible to construct concrete floor. The difference in elevation of two points which are 10 0 apart are measured as the value.

You may assume that both are identical measurements however a concrete floor slab can be flat but not level and visa versa. Although we typically achieve average flatness smoothness values in the 30s the levelness values measured on unshored elevated slabs have been as low as 10. The random traffic. The fallacy of the straightedge method was the location of the measurement.

F numbers were developed in the 1980s to provide a systematic quantitative way to indicate the flatness and levelness of a concrete floor. Comprising part of the random traffic floor shall be designated a random traffic slab. F numbers provide architects and contractors a method of determining the flatness and levelness of a concrete floor slab. 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.

The fl number relates to the general floor slope of a concrete slab from an assumed datum elevation. Section 9 precast concrete 22 100 9 1 general 22 100 9 2 precast concrete products 23 101 9 3 precast concrete elements 23 101 9 4 handling and storage 23 101 9 5 placing and adjustment 24 101 9 6 jointing 24 101 section 10 geometric tolerances 24 102 10 1 general 24 102 10 2 overall structure 25 104. An 100 flat and level concrete floor will be at a 90 degree angle to the wall and. The allowed deviation varies from 3 to 10mm depending on the flatness designation.

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. All points should be within 15mm from planned level. Where very high levels of flatness s are required as a finished floor or to take direct tiles. Floor flatness levelnessone of the things that distinguishes a high tolerance floor is its f number requirement.

Concrete slab surface flatness also referred to as surface regularity surface flatness must not be confused with surface level relative to a fixed datum. How is the tolerance of a concrete floor measured.