We use cookies for essential site functions and, with your consent, analytics and advertising. Cookie Policy AcceptReject Home About Services▾Roof CleaningPressure WashingGutter CleaningDriveway CleaningPatio CleaningDecking CleaningFence CleaningSoftwashingSolar Panel Cleaning Areas We Cover Reviews Specials Blog Contact 0800 654 6701Get Free Estimate - Home - Services - Patio Cleaning # Professional Patio CleaningThat Restores the Original StoneLondon & Surrey Deep cleaning, re-sanding and optional sealing for all patio types — flagstone, natural stone, porcelain and concrete. We remove years of algae, black staining and ground-in dirt to bring your outdoor space back to life. Get Your Free Estimate0800 654 6701 Or call our mobile: 07551 442228 ★ 5-Star Rated · All Stone Types · Re-Sanding Included 20+Years Experience 1,200+Patios Restored AllStone Types FullyInsured FreeEstimates ## What Is Professional Patio Cleaning and Who Needs It? Professional patio cleaning is the controlled removal of algae, moss, lichen, black spot, organic staining and ground-in dirt from paved outdoor surfaces using industrial equipment and targeted cleaning solutions. The goal is to restore the surface to its original colour and texture without damaging the stone, concrete or grouting. If your patio slabs have turned black, green or patchy — or if the surface is slippery after rain — it needs professional cleaning. The discolouration is caused by a combination of algae, atmospheric pollution and organic acids from leaf litter, which penetrate the porous surface of most patio materials over time. Natural stone patios (Indian sandstone, limestone, slate, granite) are particularly susceptible to staining because of their porosity. Concrete and porcelain slabs are more resistant but still accumulate surface algae and black spot lichen that cannot be removed with domestic cleaning products. We clean all patio types and adapt our methods to the specific material. The pressure, chemical treatment and joint re-sanding approach is different for every stone type — one-size-fits-all cleaning damages surfaces and produces poor results. ## What Happens If You Leave Your Patio Untreated? Algae growth on patios creates a persistent slip hazard that worsens in wet weather. The biofilm is almost invisible when dry but becomes extremely slippery after rain or morning dew. Falls on patio surfaces are a leading cause of domestic injury, particularly for older residents. Black spot lichen — the small, dark circular marks that appear on natural stone — is a particularly stubborn organism. It bonds with the stone at a cellular level and cannot be removed by pressure washing alone. Without targeted chemical treatment, it continues to spread across the surface, permanently staining the stone if left for several years. Moss growing in patio joints breaks down pointing mortar and polymeric sand, destabilising slabs and creating gaps where water penetrates the sub-base. This leads to slab rocking, settlement and — in cold weather — frost heave where trapped water freezes and lifts slabs from their bed. Weeds exploit weakened joints, pushing roots deep into the sub-base and widening gaps between slabs. Once established, weed roots are extremely difficult to remove completely, and regrowth is rapid unless the joints are properly restored. The cost to re-lay a patio in London ranges from £2,000 to £6,000 depending on the area and material. Regular professional cleaning keeps your existing patio performing and looking good for its full lifespan. Our Proven System ## How We Deliver Results 01 ### Material Assessment We identify your patio material, assess the type of staining and check the condition of joints, pointing and slab stability. This determines the correct cleaning approach for your specific surface. 02 ### Weed & Moss Removal All weeds, moss and organic growth are removed from joints and the slab surface before any pressure washing begins. This prevents spreading and ensures deeper cleaning. 03 ### Chemical Pre-Treatment Targeted cleaning solutions are applied to black spot lichen, algae staining and heavily soiled areas. These solutions break down the contamination so pressure washing can remove it completely. 04 ### Controlled Pressure Washing We clean every slab at the correct pressure for your material type using surface cleaners for even coverage. Natural stone gets lower pressure than concrete — every surface is treated individually. 05 ### Joint Re-Sanding & Sealing Joints are swept clean and re-filled with kiln-dried sand or polymeric sand. Optional sealant is applied to protect against future staining and inhibit weed growth. Why It Matters ## What You Get ### Restores Original Colour Years of staining stripped back to reveal the original stone colour and texture. The transformation is immediate and dramatic. ### Eliminates Slip Hazards All algae and biofilm completely removed, making your patio safe to walk on in all weather conditions. ### Stabilises Loose Slabs Joint re-sanding restores stability, preventing slab rocking and water penetration into the sub-base. ### Removes Black Spot Lichen Specialist chemical treatment removes black spot that pressure washing alone cannot shift — restoring clean, unmarked stone. ### Prevents Weed Regrowth Clean, properly filled joints with optional polymeric sand dramatically reduce weed establishment between slabs. ### Protects Your Investment Regular cleaning extends patio lifespan by decades, avoiding the £2,000–£6,000 cost of replacement. ## Patio Materials, Cleaning Methods & Aftercare Indian sandstone is the most popular natural stone patio material in the UK. It is porous, absorbent and available in a range of colours from buff and grey to red and brown. Professional cleaning requires moderate pressure (1,500–2,500 PSI) with a fan nozzle and alkaline cleaning solution. Acidic cleaners must never be used on sandstone as they dissolve the calcite within the stone, causing permanent surface damage and colour change. Limestone is softer and more porous than sandstone, requiring lower pressures and even greater care with chemical selection. It stains easily and is particularly susceptible to acid damage — even mild acids like citric acid or vinegar can etch the surface. We use specialist limestone-safe cleaning solutions and operate at reduced pressure with wider spray patterns. Porcelain patio tiles are non-porous and extremely hard-wearing, but their smooth surface means algae sits on top rather than within the material. This makes cleaning faster and results more dramatic. We can use higher pressures on porcelain without risk, and the tiles rarely require sealing as their non-porous surface naturally resists staining. Concrete slabs are the most robust patio material and tolerate higher pressures, but prolonged or focused pressure can still etch the surface. We use surface cleaners for even coverage and apply alkaline degreasing solutions to remove the characteristic black organic staining that concrete develops in shaded, damp areas. Granite setts and cobbles are extremely hard and tolerant of high pressure, but the irregular surface traps dirt in crevices that lance-only cleaning misses. We combine pressure washing with stiff brush agitation to clean every surface facet, particularly in the gaps between setts where moss accumulates. Joint treatment after cleaning is critical for long-term results. Kiln-dried sand is the standard re-filling option — it is inexpensive and effective but needs periodic topping up. Polymeric sand is a premium option that hardens when wet, creating a semi-rigid joint that resists weed growth, insect penetration and erosion. We recommend polymeric sand for patios with chronic weed problems. Post-clean sealing is available for all stone types. Penetrating sealants protect against staining without changing the surface appearance. Colour-enhancing sealants darken the stone slightly, bringing out the natural colour — popular on sandstone where the original warm tones have faded under staining. Common Questions ## Frequently Asked Questions ### svg]:rotate-180 text-left text-card-foreground font-heading font-medium" data-radix-collection-item="">How much does patio cleaning cost in London? ### svg]:rotate-180 text-left text-card-foreground font-heading font-medium" data-radix-collection-item="">How long does patio cleaning take? ### svg]:rotate-180 text-left text-card-foreground font-heading font-medium" data-radix-collection-item="">Can you remove black spot from sandstone? ### svg]:rotate-180 text-left text-card-foreground font-heading font-medium" data-radix-collection-item="">Will pressure washing damage my patio? ### svg]:rotate-180 text-left text-card-foreground font-heading font-medium" data-radix-collection-item="">Do you re-sand the joints? ### svg]:rotate-180 text-left text-card-foreground font-heading font-medium" data-radix-collection-item="">Should I seal my patio after cleaning? ### svg]:rotate-180 text-left text-card-foreground font-heading font-medium" data-radix-collection-item="">How often should my patio be cleaned? ### svg]:rotate-180 text-left text-card-foreground font-heading font-medium" data-radix-collection-item="">What areas do you cover? ## Related Services Driveway CleaningDecking CleaningPressure WashingFence Cleaning ## Ready to Get Started?Your Free Estimate Is One Call Away No obligation. No hard sell. Just honest advice and a clear price from a family-run team with over 20 years of experience. Get Your Free Estimate0800 654 6701 Or call our mobile: 07551 442228 2hr Response Fully Insured Fully Insured Family-run roof cleaning and pressure washing specialists serving London & Surrey. Over 20 years protecting your property. ### Services - Roof Cleaning - Pressure Washing - Gutter Cleaning - Driveway Cleaning - Patio Cleaning - Softwashing - Decking Cleaning - Fence Cleaning - Solar Panel Cleaning ### Areas We Cover - London - Surrey - Worcester Park - Sutton - New Malden - Morden - Chessington - Coulsdon ### Contact 0800 654 6701 07551 442228 mossmenlondon@gmail.com55 Wolsey Close, Worcester Park, Surrey, KT4 7EF Opening Hours:24 Hrs Line Open, Monday – Sunday Our WorkBlogSpecials & OffersCustomer Reviews © 2026 Moss Men Roof Cleaning London. All rights reserved. Privacy PolicyTerms & ConditionsCookie Policy Call NowFree Estimate