How to check the substrate before microcement application? A smart tip to protect against concrete cracking


In today’s film, Borys will show you how to easily assess the quality of the substrate before applying the microcement. This simple test will immediately tell you whether the concrete screed on which we plan to apply the microcement has defects in the form of cracks. This type of study will allow you to understand more precisely why fiberglass mesh installed over FESTKontakt adhesion promoter is a very good solution for the implementation of microcement floors.


How to check the substrate before microcement application?

The most common place to use microcement is the bathroom. There, usually microcement is laid on various types of concrete floors and self-leveling screeds. Always assess the surface quality before starting work to avoid any later unpleasant surprises. Let’s just remind you right from the start that microcement can be applied after the screed has dried thoroughly. Although quick-drying and binding screeds are available on the market, it is a good practice to wait 1 day for every 1 mm of floor thickness (that is if the floor/screed is 15 mm you need to wait 15 days). Fresh concrete screeds are especially tricky, because at first glance they give the impression of even and smooth surface. It seems that they do not require any additional treatment. However, this is not the case.


A clever way to protect against cracks in concrete

When we lay the primer for the screed, we can see a whole network of larger or smaller cracks and scratches. In addition, some of them will get worse or new ones will appear. A similar situation occurs when we are dealing with an old damaged floor, on which defects have been filled/repaired, or when too little expansion joints have been made on the concrete floor. If the substrate is not properly secured, scratches can propagate to the surface of the microcement. Although microcement is a fairly flexible coating, it can sometimes not withstand such stresses. That is why ground preparation is so important. We always recommend the use of bonding bridge and fiberglass mesh for this type of special task.

Read also: Why is it better to strengthen the substrate with adhesion promoter and not with epoxy resin

Watch the video to see what it might look like. Don’t forget to turn on the subtitles (English & Spanish).