Indian sandstone is popular, porous and unforgiving. It marks under a lance, it absorbs everything from barbecue fat to plant pot rings, and its natural colour variation gets blamed on the cleaner.
Pressure marks are permanent
Hold a lance too close and you leave a lighter stripe where the surface has been eroded. Nothing brings the surrounding stone back to match, so the whole patio has to be worked at consistent distance and speed.
This guide sits under our Patios & Driveways work, covering 20-mile radius of Plymouth.
Blotches that will not lift
Dark patches that stay wet-looking after everything else has dried are usually moisture from below or a deep organic stain. That is a bedding or drainage issue, not a dirty slab.
Sealing sandstone
A breathable sealer reduces future staining and makes the next clean much easier. It should go on clean, fully dry stone - not the same afternoon.
Questions we get on this
- Will the colour variation even out?
- Cleaning removes the growth; the natural colour range of the batch stays. Photos before and after help set expectations.
- Do you re-point the joints?
- We can point out failed pointing and clear it; re-pointing a patio is separate work.
- Is sealing worth the extra?
- On sandstone, usually yes, particularly under a dining area.
Related reading
- Bird droppings, nesting debris and blocked outlets
- White powder on brickwork: efflorescence explained
- Cracked render: what to fix before cleaning
- Weeds and moss in driveway joints