Pre-application conditions and substrate preparation

Conditions prior to application

Cleanliness.

The substrate must be clean, free of dust and grease.

Flatness.

Microcement is applied in layers of no more than 1mm, and the sum of these will not exceed four millimetres, so we cannot solve flatness issues with this material, we must solve the irregularities of the support before starting the application. The Microcement can be applied on floors, walls and even ceilings, the final result will depend on the substrate and the work of the applicator.

Consistency.

The application base must be stable. Substrates with powdery mortars or loose tiles are not suitable; depending on their state, they will have to be removed or consolidated with quick-setting mortars with compensated shrinkage.

Free of damp.

If there is damp in the substrate, microcement cannot be applied. It will be necessary to first determine its origin and eliminate it, we recommend using a moisture meter to check that the humidity never exceeds 5%.

The substrate must have undergone a sufficient setting process. We must bear in mind that the temperature and relative humidity of the environment, together with the ventilation of the work space, affect the drying process of the mortars and accelerate or delay the setting process.

Protection of the work area

We must protect the work area properly and the surfaces that we are not going to cover, as microcement adheres very strongly and is difficult to clean when it dries. We will use protection material common in painting works, such as painter's tape, protective paper, plastic covers...

Recommended support in the swimming pool system

It is applied on sprayed or gunned concrete, the support being clean, consolidated and in good planimetric conditions. It must not be applied on stoneware.

Preparation of the substrate

The application of the microcement will begin with the priming of the substrate using adhesion promoters and the placement of the fibreglass mesh.

Priming with adhesion promoters

Adhesion promoters have several functions: they ensure better adhesion on any type of substrate, increase its cohesion, improve the speed of application of the first coat of microcement, and prevent the premature loss of moisture from the micro-mortar.

Supports have different absorption capacities, so we must use solutions for each of them, promoters for non-absorbent surfaces, for absorbent surfaces, for surfaces that need a certain degree of consolidation or promoters for surfaces that may have moisture problems.

Microcement on stoneware, terrazzo, hydraulic tile or marble

To coat this type of support that is not very porous or not at all porous, we must use Primacem Plus, promoter for non-absorbent surfaces, the process will be as follows:

• Fill the joints with Microbase and leave to dry for 24 hours. If the joints are very thin we can use Microdeck or even Microfino.
• Apply a layer of Primacem PLUS by roller together with the Builtex mesh.
• Allow to dry for at least 30 minutes and apply the first coat of Microbase.
• Allow to dry for 24 hours, apply a coat of Primacem PLUS and apply the second coat of Microbase.

  Here we see a different application system with Impoxi

  Microcement on plaster, plasterboard, MDF boards

  On absorbent substrates we will use Primacem Abs, following these steps:

  • Apply the primer with a common painter's roller.
  • Let the bonding agent act for a minimum of 30 minutes and a maximum of 24 hours before applying the mesh together with the first coat of microcement.

  
  Microcement on cement mortar, shotcrete or gunned concrete.

  For absorbent surfaces that may require a certain degree of consolidation, proceed as follows:

  • Apply the Acricem primer with a common painter's roller.
    
  • Let the bonding bridge act for a minimum of 30 minutes and a maximum of 24 hours before laying the mesh together with the first coat of microcement.

  Microcement on substrates that may have damp

  On consolidated substrates where damp may appear, a barrier based on epoxy resins should be applied to prevent damp from affecting the microcement. Primpaox Barriersolves moisture problems by allowing microcement coatings to be applied on the substrate.

  • Roller priming with Primapox®100 Barrier At 0.35 kg/m2
  • Dust with 0.3-0.8 mm dry silica sand at 1kg/m2
  • Let dry for 24 hours
  • Remove the excess silica sand by sweeping and vacuuming.
  • Apply Primpaox Barrierby trowel at 3 kg/m2

  Installation of the mesh

  Topciment microcement does not crack, as long as the base on which it has been laid does not crack. The Topciment mesh is an additional insurance in microcement applications, it is a high performance mesh, flexible, resistant and very easy to work with, it is easily covered with Microbase, without making pockets. The mesh allows the coating to be uncoupled from the application substrate.

  Fixing the mesh:

  The mesh can be fixed with Primacem Plus adhesion promoter, or when Primacem ABS or Acricem resin is used as a promoter, with the first coat of Microcemento Base. The mesh strips should overlap, no more than 1cm, and always apply two coats of Microbase to completely cover the grid.