There's no single answer: it depends on where on the island you are, which way the floor faces and how much it's used.
By area
- Coast with salt: one technical clean a year.
- Damp highlands: at the end of the rainy season, usually once a year, with preventive algae treatment.
- Sunny south: every 12–18 months, or before high season for holiday lets.
- Sheltered inland areas: every 18 months is usually enough.
Signs it's time
The floor looks darker, green or black patches appear in corners, it's slippery when wet, or water no longer beads on a sealed floor.
Between cleans
Sweep often, rinse after calima, rinse with fresh water on the coast after rough seas, move pots that trap damp, and keep drains clear.