Black spots on patios are one of the most frustrating outdoor cleaning problems for homeowners across the UK. Many people spend hours pressure washing their patios, only for the black spots to remain visible or quickly return.
At Shark Cleaning Chemicals, we’re often asked why pressure washing alone doesn’t fully remove stubborn black spots from paving and natural stone.
What Are Black Spots On Patios?
Black spots are usually caused by deeply rooted organic growth such as:
- Black lichen
- Algae
- Fungal growth
- Embedded biological staining
Unlike normal dirt or surface algae, black spots often penetrate deep into the pores of the paving surface.
This is why they can be extremely difficult to remove using water pressure alone.
Why Pressure Washing Often Fails
Pressure washing is excellent for:
- Surface dirt
- Loose moss
- Mud
- General grime
However, black spots are different.
Many homeowners notice:
- The patio looks cleaner initially
- But black spots remain visible
- Or quickly return afterwards
This happens because pressure washing may clean the surface while leaving the rooted growth underneath intact.
In some cases, excessive pressure washing can even:
- Damage pointing
- Mark softer stone
- Wear patio surfaces over time
The Best Way To Remove Black Spots
To properly tackle black spots, a dedicated black spot treatment is usually required.
Using a specialist product helps target the organic growth more effectively than water pressure alone.
Shark Black Spot Remover
Shark Black Spot Remover is designed to help tackle stubborn black spots on:
- Patios
- Driveways
- Paving
- Natural stone
- Outdoor hard surfaces
Why customers choose it:
✅ Powerful formula
✅ Fast acting results
✅ Suitable for outdoor surfaces
✅ Trusted by customers across the UK
Common Surfaces Affected
Black spots commonly appear on:
- Indian sandstone
- Concrete paving
- Block paving
- Porcelain edging
- Garden paths
- Driveways
Damp conditions and shaded areas can often make the problem worse.
Tips For Best Results
For best results:
- Apply during dry weather
- Allow the product time to work
- Avoid rainfall immediately after application
- Follow product guidance carefully
Looking To Restore Your Patio?
Browse our outdoor cleaning range at:
Including:
- Black spot removers
- Patio cleaners
- Render cleaners
- Weed killers
- Natural stone cleaners
- Driveway cleaners