Pressure washing guide
How to remove moss from a driveway
Moss colonises London driveways rapidly in damp and shaded conditions. Left unchecked it becomes dangerously slippery and embeds itself into joints and surface cracks. This guide covers the most effective removal methods for each driveway surface type.
Moss is one of the most persistent surface problems on London driveways. The city's high rainfall, mild temperatures and the extensive shade created by surrounding buildings and vegetation create near-ideal growing conditions for moss across most of the year. Beyond the appearance, moss makes surfaces slippery when wet, forces its way into paving joints and cracks over time and can accelerate surface deterioration. The most effective removal method depends on the driveway surface material and how established the moss growth is.
Kill first
always kill the moss with a biocidal treatment before pressure washing for best results and slower regrowth
Tarmac caution
moss roots replace bitumen between tarmac particles — pressure wash only after killing, use low pressure
Re-sand
block paving joints must be re-sanded after every pressure wash to prevent moss returning rapidly in open gaps
The right approach for each driveway surface
Concrete
Apply a biocidal moss killer, wait until the moss turns yellow or brown (typically 24 to 48 hours), then pressure wash at 2,000 to 2,500 PSI with a fan nozzle. Concrete handles high pressure well.
Block paving
Kill with a moss killer, pressure wash diagonally across the joints at medium pressure, re-sand the joints with kiln-dried sand after the surface has dried. Re-sanding is essential.
Tarmac
Kill the moss first and allow it to die fully before any pressure washing. On established tarmac moss the roots bond with the bitumen particles — brush away dead moss carefully and use low pressure if washing. High pressure strips the surface.
Resin-bound
Apply a moss killer designed for resin surfaces. Use cold water only when pressure washing, flat spray nozzle at a maximum of 150 bar. Hot water and excessive pressure damage resin binding.
How to remove moss from a driveway: the recommended process
Step 1: Apply moss killer first
Apply a biocidal moss killer or iron sulphate-based product to all moss-affected areas. This kills the moss from the root, making subsequent pressure washing more effective and slowing regrowth. Allow 24 to 72 hours for the moss to die and change colour.
Step 2: Brush away dead surface moss
Once the moss is dead, use a stiff broom to sweep away the bulk of the surface layer. Collect all loose debris to prevent spores spreading to adjacent areas.
Step 3: Pressure wash the surface
Use the correct pressure for your surface type. Work from one end using a fan nozzle in overlapping passes. For block paving, work diagonally to the joints to avoid sand loss.
Step 4: Final rinse
Rinse thoroughly to clear remaining moss residue and product from the surface and from the drain area.
Step 5: Re-sand block paving and apply prevention treatment
Re-sand block paving joints once dry. Consider applying a biocidal prevention spray or sealing the surface to slow future moss establishment. Improving drainage and reducing shade also helps prevent rapid regrowth.
Professional pressure washing London
Driveway moss removal across London
Cloud Nine removes moss from driveways across London using the correct kill-first approach for lasting results. We use biocidal pre-treatment, commercial pressure washing and re-sanding where needed. Contact us for a free quote.
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Everything you need to know about pressure washing for London homes and businesses.
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