Suggestions & Solutions

Detachment of a mosaic in a swimming pool: Issue & Solution

Suggestions and Solutions from Hadjiyiannis and Isomat!


Pool masonry with polyurethane insulation


Detachment of mosaic

Possible causes

The possible causes of this particular problem can be attributed to the following:

  1. Lack of adhesion of the tile adhesive to the polyurethane-based sealant of the substrate, due to insufficient adhesion of quartz sand to the fresh sealant.
  2. Insufficient waterproofing of the pool.
  3. Wrong choice of tile adhesive.


  1. First, the detached tiles should be removed. Piping and lighting must be checked for leaks.
  2. This is followed by cleaning the surface of dust and loose materials.
  3. The polyurethane primer PRIMER PU-100 is applied, followed by the polyurethane spreadable sealant ISOFLEX PU-510 in two layers. After the application of the second layer and while it is fresh, it is covered with quartz sand (Consumption of quartz sand about 3kg/m2).
  4. After ISOFLEX PU-510 has hardened, it is recommended to stick the new tiles with high-quality resin adhesives, such as ISOMAT AK-25 and ISOMAT AK-22.
  5. The surface is then grouted after at least 48 hours. At low temperatures the times are extended.