Coating over smooth concrete

Coating over smooth concrete

In general, concrete has a very smooth surface, vitrified appearance and low porosity that prevents the good adherence of mineral coatings such as one-coat mortars, which act by means of mechanical adherence.

To achieve good adherence to these types of smooth, non-porous surfaces, the use of synthetic resins added to the mortars or the application of a union bridge is required in order to finally obtain chemical-type adherence.

Preliminary analysis

There are three types of treatments in the application of coating mortars to these types of substrates (non-absorbent and very smooth):

  • Application through the addition of synthetic resins to the mixing water (GECOL Látex).
  • Use of an adherence bridge over the surface to be coated (GECOL Primer-M).
  • Use of a product suitable for direct application to these types of low-absorption substrates (GECOL Monocapa premium).

In all cases, the surface must be previously cleaned, removing dust, salt residue, release agents, etc. and treated with GECOL Desincrustante to open its porosity.

Subsequently, clean thoroughly with water.

Technical considerations

  • Application by addition of GECOL Látex:

Mix until obtaining a homogeneous, consistent paste using 2 liters of GECOL Látex and 25 kg of the chosen coating mortar.

Apply a 2-5 mm flat base coat to the substrate without retouching.

The base coat must have the consistency of mortar and, after 24 hours have elapsed, we must check that it is sufficiently solid to receive the final mortar coat. If not, soak with water and wait an additional 24 hours.

Next, apply the finish coat after 24 hours have elapsed using the coating mortar.


  • Application of bonding bridge GECOL Primer-M:

Mix two volumes of GECOL Primer-M and one volume of water with the help of a slow mechanical agitator (500 rpm) and apply the mixture to the substrate using a wool roller or brush.

During the application, mix the product in order to prevent sedimentation.

Once the GECOL Primer-M union bridge has dried (drying time ranges from 1 to 24 hours, depending on ambient conditions), apply the coating mortar.

Bear in mind that the mortar must never be applied with the bonding bridge (GECOL Primer-M) still moist, nor should more than one workday elapse between the installation of the adherence bridge and the coating mortar.

Recommended products

Mineral coatings

Lightened Monolayer

Semi- Lightened Monolayer

Stone finish

Based on cement and lime

Air lime fine plaster

Based on hydraulic lime

Fine plaster

Fine plaster aerial lime

Hydraulic lime fine plaster


Acid cleaner

Bonding bridge

Polymeric binder

Warnings: The data provided by this Constructive Solution were prepared based on standard onsite installation processes. However, we recommend that you consult our Technical Department in the event of any specific circumstance