Smoothing the Way to a Perfect Subfloor
19th September 2023

Smoothing the Way to a Perfect Subfloor

One of the most important parts of installing a new floor is ensuring that the subfloor is in a fit state to receive the covering.  It should be sound, dry, clean, and smooth or the finished flooring will have problems varying from the appearance to debonding and complete failure.  The way to avoid such issues is to properly prepare the surface.

One of the most important elements is the humidity of the screed; if it is too damp the installation is sure to fail.  First check for humidity: the Tilemaster Hygrometer is literally made for the job as it is a surface-mounted, non-destructive device for testing the Relative Humidity (RH) of the substrate.  If this is more than 75% RH, you must apply a damp proof membrane.  

We recommend Tilemaster FAST One Coat DPM which is one of the most advanced available on the market.  This epoxy resin DPM can be installed as a one coat application even where there is no structural DPM present.  It is suitable for use on a wide range of substrates including concrete, sand/ cement screeds and calcium sulphate screeds, and is fast curing being ready to receive smoothing compounds in 4-5 hours in ideal conditions.  It can also be used with underfloor heating systems.

You can use FAST One Coat DPM on surfaces with moisture readings of up to 98% RH, on heated calcium sulphate screeds with up to 90% RH which rises to up to 95% for unheated calcium sulphate screeds.

Where the substrate is rough or uneven, you should pre-smooth it before applying the DPM.  Tilemaster Super Flow 30 is moisture tolerant and ideal for use under a DPM.  An additional coat should be applied over the Tilemaster FAST One Coat DPM once it has cured.