What gresite is and why it comes away
Gresite (glass mosaic tile) is a mosaic made of small glass-paste pieces, widely used in Costa Blanca pools for its resistance to chlorine, sunlight and permanent immersion. It is fixed to the pool shell with a cement-based adhesive made for pools and finished with waterproof grout between the tiles.
Over the years several things can make gresite fail: movement in the shell from thermal expansion, water seeping under the tiles through worn grout, adhesive that was poorly applied in the first place, or simply natural wear after many seasons of use.
Signs your pool needs its gresite re-bedded
Check these points:
- Loose or missing tiles, especially along the waterline and on the steps.
- A hollow sound when you tap gently on an area of the mosaic.
- Cracked or opened grout lines, exposing the mortar beneath.
- Damp patches on the outside of the shell, a sign of seepage.
- The water level drops more than usual with no obvious cause.
If you notice any of these signs it pays to act early: a small patch of loose gresite can turn into a much larger failure if water keeps seeping under the mosaic.
How we bed and re-bed gresite
- Draining the shell partially or fully, depending on the affected area.
- Chipping out and removing loose or damaged gresite without disturbing the sound areas.
- Preparing the substrate: cleaning, crack repair and levelling of the mortar.
- Laying new tiles (or salvaged ones where possible) with adhesive rated for permanent immersion.
- Re-grouting with waterproof grout, matching the tone of the rest of the shell.
- Allowing the adhesive and grout to dry and cure before refilling.
- Refilling and treating the water so the pool is ready to swim in.
Where the damage is localised, the work can be limited to the affected area. If the gresite is many years old and the problem keeps reappearing in different parts of the shell, a full re-surfacing of the pool often works out better value, and it is a good moment to weigh up alternatives such as ceramic tiling or pool paint.
Gresite, ceramic or paint: when to change finish?
Re-bedding makes sense when the problem is localised and the rest of the gresite is sound. When the deterioration is widespread, it is a good moment to compare options: our article on gresite, ceramic or paint: choosing your pool finish sets out the advantages of each.
At AquaGarden Alicante we assess the real condition of your gresite with no obligation and tell you honestly whether re-bedding will do or whether a full re-surfacing of the shell makes more sense.