Patio maintenance and repairs
Part of our patios guides
Most patio problems come down to three things: algae, failed pointing and slabs that were never bedded fully. Each has a different fix, and cleaning will not solve the last two.
Cleaning without doing damage
A stiff brush, warm water and a patio-safe cleaner handle most seasonal green growth. Pressure washing works but is the main cause of blown pointing and pitted sandstone: keep the pressure moderate, hold the lance at an angle and keep it moving. Avoid acid-based cleaners on limestone entirely.
Why pointing fails
Joints crack out when the mortar was too weak or too dry when packed, when the slabs move because they were spot-bedded, or when a pressure washer has cut it away. Repointing a patio that is still moving underneath will fail again within a season — the movement has to be fixed first.
Modern resin-based jointing compounds are more flexible and much faster to apply than a traditional mortar joint, but they still need clean, damp, correctly sized joints and a stable slab underneath.
Rocking and cracked slabs
A rocking slab is a void under it. It can be lifted, the old bed removed and the slab re-bedded on a full mortar bed — usually a half-day job for a small area. A cracked slab is normally the same story: the crack formed over the void.
Where more than a few slabs are moving, the pattern is telling you the whole area was spot-bedded, and relaying the section is more economical than repeated individual repairs.
Frequently asked
How often should a patio be cleaned?
Once a year for most gardens, usually in spring. Shaded, north-facing or tree-covered patios green up faster and may want a second clean in autumn.
Can individual patio slabs be replaced?
Yes, provided a matching slab can be sourced. Natural stone weathers, so a new slab will look brighter for a while. Where an exact match matters, lifting a slab from a hidden area and putting the new one there instead gives a better result.