We will analyze how important the Primer is on a Flooring System and which type of primer Casali suggest

When designing and building a flooring system you may wonder how important is the primer? Why should I use it and what type of primer should I pick?

We will try to answer those questions with the help of a few photos of a real jobsite and a quick explanatory video.

In many flooring projects either indoor or outdoor and in most of the waterproofing jobs we are going to install the system over a substrate which will be concrete of asphalt and in most of the cases the system will be “fully bonded”, so there will be full adhesion between the system (waterproofing or sport flooring) and the substrate.

We can consider that the system and the substrate will work together to guarantee durability and stability. Their integration will be the key for a successful execution of the job.

A few important factors need to be taken into consideration

The breakdown:

  • what is the primer ?
  • why using the primer
  • what type of primer
  • primers for metal sheet roofs

What is the primer ?

The primer is a promoter of adhesion, that means it helps to improve the bonding between the substrate and the top coating.

The substrate is concrete in most of the cases.

The primer is not a glue and it does not stick on the surface of the concrete, but it is absorbed into the substrate and it penetrates in the top layer of the concrete due to the specific formulation and the porosity of the concrete itself.

The main scope of the primer is to prepare the concrete surface in order to apply any coating

Why using the primer

The concrete subbase is normally dusty and dirt (to see the different surface with or without dust go to 0.21 of the videoclip HERE). This prevents having a good bonding between the concrete and the coating on top of it. The coating will more likely fail sooner.

We have several advantages on using the primer:

  • The primer consolidates the concrete;
    It will avoid loose parts of the concrete before the application of the coating on top
  • The primer avoids having a dusty surface;
    The dust prevents the bonding with the risk that the coating on top will chip off sooner or later.
  • The primer improves the bonding; it makes a strong bonding between the concrete and the coating on top.
  • The primer improves the overall lifespan of your coating system; the use of the primer drastically improves the life of your coating system and sometimes it is simply not possible to have a successful application without using primers.

What type of primers

There are several types of primers in the market, what Casali is using the most are epoxy primers and acrylic primers.

These two types of primers have, of course, different applications and different destination of use.

Epoxy primers:

Epoxy primers like Epobase or Epobase A are mostly indicated for concrete subbases in order to achieve the advantages above mentioned.

Other primers like Multifixo 100 are also epoxy primers expressly formulated to create the bonding with metal sheets, so they are specific for the waterproofing industry (see the part below “primers for metal sheet roofs“).


The Epobase is a concentrated epoxy primer with an extreme durability and capability of bonding, it is mostly indicated for heavy uses such as car park, heavy traffic and drive over. Its specific composition makes it cure very fast and when it is mixed with quartz sand it can be used also to re-surface the damaged and uneven concrete subbases.

Epobase application on concrete

The above photo shows the application of Epobase with quartz sand to prepare the subbase in a very uneven concrete surface. Contact Casali ABM team to learn more about this process.

Epobase A

The Epobase A is a version of Epobase and it is mostly indicated for projects where we need bonding between concrete subbase and a sport coating system. The Epobase A is not particularly indicated for car park or drive over (where we normally use Epobase) but is is a perfect solution for indoor or outdoor sport project.

See a related clip HERE where at 0.59 there is a practicle application of Epobase A.

Epobase A application

The above photo shows the application of Epobase A on a concrete subbase where we have installed an indoor PU flooring. Contact Casali ABM team to learn more about this process.

The Epobase A is classified as standard product and it is not subject to specific charges like DG products, it is ready to use and the application is easy and smooth.

Acrylic primers:

Acrylic primers like Acrybase (or Acrybase S) are commonly used for resurfacing on old acrylic resins such as an old sport acrylic court.

The special acrylic-based formula is expressly indicated to create the best bonding with the old acrylic court in order to prepare the surface for the application of the new acrylic sport system such as Supersoft WS for example.

Acrybase application

The above picture shows the application of the Acrybase over the old acrylic resin.

The application of Acrybase has the same scope of the application of other primers above mentioned; the surface needs to be prepared and consolidated to allow the good bonding of the coating system on top of it.

Whenever we need to resurface an old acrylic flooring we always face the coating to be weak and loose and many times we have detachment and peeling off. If this type of surface is not treated with an acrylic prmer the chances that we will have issue when we apply the new coating on top are high.

Same as the concrete, also the old acrylic resin might be dusty and dirt, this will affect the bonding and the adhesion of the new coating system with the old one.

peel off 1
peel off 2

The photos above show the issue caused by the missing application of the primes; some spots peel off and are completely detached. The old acrylic court (bright blue) was resurfaced without applying any primer before the application of the new coating (dark blue).

This resulted in additional fixing and additional costs for the court owner.

How important is the primer on a flooring surface? Those photos perfectly show the issues that the applicator encountered just because the primer was not used before the application of the new coating.

Primers for Metal Sheet Roofs

When it comes to roofing we are often encountering jobsites where the rooftop is made with metal sheet. This is particularly true in areas like Southeast Asia there the metal sheets are often the preferred type of roof for constructions like warehouses and factories.

Normally you face metal sheet roof leakage whenever the metal is damaged by the rust or in between the joint and the overlapping between the sheets. This will result in overall leakages and the necessity of a fixing that guarantees a long lasting waterproofing. 

The metal sheets are extremely glossy and the lack of grip makes the bonding with the waterproofing system almost impossible to sustain in the long run.

Multifixo 100

Multifixo 100 is an epoxy primer and an excellent solution to the lack of bonding. Its specific formulation will aggressively stick on the metal sheet and the presence of quartz sand dispersed in its emulsion will give a rough texture that is perfect to create the good bonding where the waterproofing product will be applied.

Application Multifixo on metal sheet

The above photo shows the application of Multifixo 100 on the metal sheet roof. the product is applied all over in order to apply Acryrubber for waterproofing.

See also the video clip of this case study HERE where there is the application of Multifixo 100 on metal. The jobsite was having leakages between the wall and the metal flashing. The problem has been solved by using Multifixo 100 too before the application of the waterproofing coating Acryroof Plus Fibro.


We believe that the durability of any system either sport flooring or waterproofing is a MUST to pursuit. The Client’s satisfaction is optimized when his budget matches the expectation of the system, also in terms of durability.

The correct choice of the primer and the correct use can extensively increase the lifespan of the system and will avoid continuous fixing and waste of money.

As a matter of fact, the reduced cost of the primes are making this product worth to be considered and used whenever the condition of the jobsite require it.