2019 Highly Commended - Hawley Wharf, London

Concrete @ your Fingertips

Full list of Nuggets

Surface regularity - levelness and flatness

The surface profiles of a slab need to be controlled so that departures from a theoretical flat plane are limited to an extent appropriate to the planned use of the floor. Levelness and  flatness tolerances define the allowable or permitted variation in of a floor surface. Surface regularity needs to be limited in two ways:


 - Flatness, in order to limit for example the bumpiness

 - Levelness, to ensure that the building as a whole can function satisfactorily.


Flatness relates to variations over short distances whereas levelness relates to variations over longer distances.  These distances are not easily definable but traditionally, flatness is concerned with variations in the surface plane over much shorter distances, e.g. 300mm whereas levelness is concerned with the variations in surface ‘level’ over distances of around 3m.


The relation of the actual surface plane to the theoretical surface plane is often referred to as level to datum.

Acknowledgement: The Concrete Society

Concrete Bookshop - Members receive 40% discount on Concrete Society publications

TR34 Concrete industrial ground floors
a guide to design and construction - 4th Edition