How to level a floor for tiling

It is important, both for appearance and for safety, that the finished tile surface is flat with no tiles standing higher than the others. Providing the normal tiling practices are followed this is straightforward on flat, level substrates. If the substrate is not flat then a number of problems can arise.

Common issues and queries you can face


Increased difficulty in achieving a flat finish

A notched trowel, used at a constant angle, enables even distribution of adhesive onto the substrate. If the tiles are all bedded with a similar force they should be at the same height with only minimal unevenness. However, if the substrate is not level, this is much more difficult to achieve and there is more chance that some edges will stand proud.


Extra time required to fill holes

Localised deep holes may result in a bed thickness that exceeds the specification for a thin-bed adhesive. Patching such holes can be time consuming if there are more than a few of them.


Combination of problems

In some instances, for example when tiling over a layer of existing ceramic tiles, the above mentioned problems may be combined. Some tiles may need to be removed because they are unsound, whilst others may have been imperfectly fixed and exhibit some variation in height.


Some natural stones are not a constant thickness

Uncalibrated natural stones are stones that have been split along natural fracture planes rather than machine cut. The result is a stone that varies in thickness, both from within each stone and from piece to piece. These types of stones require an adhesive that can be applied to a greater thickness than normal.