Renewal of waterproofing in exteriors

Materials exposed to frequent changes in temperature suffer greater wear and, consequently, the purposes for which they were designed may be compromised.

Waterproofness and watertightness of surfaces in the construction of floors or cladding is not ensured with traditionally used materials.

Solutions with asphalt sheets and mortar and concrete compression layers have non-applicable, excessive thicknesses.

The alternative would be the demolition and complete renewal of the existing substrate, with the ensuing hassle and high cost.

However, the use of elastic cementitious membranes, directly coatable with adhesives for laying ceramic material, solve renewals of this type of exterior surfaces.

Preliminary analysis

When ensuring the total waterproofing of a substrate, we must use a solution:

  • That allows the renewal of exterior floors, without need to remove the previous floor.
  • That is functional in terms of waterproofness and does not generate excessive thickness problems.
  • That is flexible. That is capable of resisting temperature changes and minor structural movements.
  • That is resistant to the pressure and counter pressure of water.

The specific products are capable of fulfilling all of these requirements are GECOL Imper-E o GECOL Imper-R, which are bicomponent elastic cementitious waterproofing membranes. In addition, GECOL Imper-R contributes a fast setting to the system.

As opposed to other traditional constructive solutions, these membranes can be subsequently clad with ceramic material. In this specific case, the use of deformable adhesives such as GECOL Flexible premium or GECOL Flexible rápido is required.

Technical considerations

The first step is to prepare the substrate. To this end, we must:

  • Adequately clean the substrate, ensuring that it is free from surface grout and residue. Make an acidic cleaning with GECOL Desincrustante and subsequent rinsing with water.
  • Subsequently, fill in the cavities and voids of the concrete substrate with a repair mortar of the GECOL Reparatec game.
  • In the case of very absorbent substrates, it is advisable to previously moisten them and apply the product when the film of water disappears.
  • Once the substrate is prepared, we will proceed to perform the waterproofing treatment and subsequent cladding with the ceramic material.

Recommended products


Fast setting

Thin layer 3 mm Elastic

Thin layer from 2 to 5 mm

Thick layer 10 mm


Concrete repairers



Structural- fast setting


High deformability

Ultra-fast setting

High performance


Acid cleaner

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