Cracked swimming pool grout — repair or eliminate permanently?

Why grout cracks

Grout mortar — usually cement-based, sometimes epoxy — has different expansion behaviour compared to tiles and concrete. With every seasonal or temperature change, microscopic stresses arise between the three materials. On the weakest link — usually the grout — this stress manifests as hairline cracks that widen year after year.

Existing repair techniques

Option 1: grind out existing grout and refill with epoxy grout mortar. Effective for 3–7 years but only addresses cause 1 (chemical degradation). Option 2: full grout renovation with flexible sealant. Short lifespan (~3 years) and cosmetically less appealing. Option 3: local removal of severely damaged areas and re-grouting. Temporary intervention.

None of these options address the three other fundamental causes (thermal expansion, frost, mechanical fatigue).

The structural solution — no grout

During an ACRATON® Dolphin renovation, all grout lines disappear into the epoxy levelling layer, and the pool finishes as one continuous surface. What isn't there cannot crack. This is the only approach that eliminates all four fundamental causes in a single intervention.

Cost comparison

Annual grout maintenance typically costs €1.50 to €4 per m² per year for a public pool. A one-off coating renovation — depending on the initial situation — ranges between €80 and €130 per m² as a single payment. The point at which renovation becomes financially more favourable than annual grout maintenance typically occurs in years 4 to 7.