# How to Clean Driveway Stains | Moss on Tarmac URL: https://dublincleaners.ie/blog/how-to-clean-driveway-stains/ > How to clean driveway stains from oil, rust and moss on tarmac and block paving, pressure wash safely and keep run-off out of drains. Call 01 230 8646. How to # How to Clean Driveway Stains: Oil, Rust and Moss on Tarmac and Block Paving ![Lana, founder of Dublin Cleaners](/img/lana-founder-dublin-cleaners-96.webp)By [Lana](/author/lana/), Founder of dublincleaners.ieUpdated 14 November 2026 Quick answer **To clean driveway stains, treat each one by type.** Soak up fresh oil with cat litter, then scrub with hot water and washing up liquid. Lift rust with a rust remover made for paving, and scrape moss before brushing. **Pressure wash block paving at a 30° angle on medium pressure**, and **keep chemical run-off out of road drains**. Key takeaways - Marshalls advises pressure washing block paving at a 30° angle, sprayed diagonally on medium pressure, to avoid marking the surface and loosening joint sand. - Dublin City Council explains that surface water drains carry rainwater to local rivers and streams, not to a treatment plant. - The Health and Safety Authority's home chemicals leaflet tells householders to read the label and never mix chemicals. - Fresh oil is far easier to lift than old oil, so cover a new spill with cat litter or sawdust within minutes. - Tarmac is bound with bitumen, a petroleum product, so solvent degreasers and high pressure can soften or strip it. - Moss grows where paving stays damp and shaded, which describes many north-facing Dublin driveways from October to March. - 30° Pressure washer angle for block paving Marshalls - 1977 Water Pollution Act under which Dublin City Council inspects drains Dublin City Council Knowing how to clean driveway stains starts with knowing which stain you have. Oil, rust and moss each need a different method, and the surface matters just as much. Tarmac and cobblelock block paving, the two most common Irish driveways, react very differently to solvents and pressure. This guide covers both, plus how to keep cleaning products out of the drains. ## What causes driveway stains on tarmac and block paving? Most driveway stains come from three sources: oil and fuel from cars, rust from metal objects or fertiliser, and moss or algae from damp. In Ireland’s wet climate, the green growth is often the biggest job. Oil is the hardest to shift once it soaks in. Tarmac is a mix of stone and bitumen, which is itself a petroleum product. That means oil and solvent cleaners can soften it. Block paving and concrete are cement-based and porous, so stains soak into the surface rather than sitting on top. The cleaning work outside is a separate trade from what we do. Dublin Cleaners works inside homes, offices and rentals, and our [full list of services](/services/) shows what we cover. Driveway washing is not on it, so the steps below are written for doing it yourself. ## What materials do you need? You need simple tools, and most stains need no chemicals at all. The table matches each item to the job. Material Use it for Notes Cat litter, sawdust or dry sand Soaking up fresh oil Bag it for the bin, never sweep into a drain Stiff yard brush Scrubbing stains and moss Cheaper and safer than a pressure washer Washing up liquid and hot water Light oil, grime, tyre marks First choice for most stains Driveway oil remover Old, set-in oil Check it suits tarmac or paving Rust remover for paving Orange rust marks Test on a hidden corner first Flat shovel or patio knife Scraping moss and weeds from joints Work along the joints, not across blocks Pressure washer with fan nozzle Block paving and concrete Medium pressure, 30° angle Kiln-dried sand Re-filling joints after washing Only on a fully dry surface Rags or a sandbag Blocking the road gully Stops run-off reaching the drain ## How to clean driveway stains from oil You clean oil off a driveway by soaking up as much as possible first, then scrubbing what is left with a degreaser. Speed matters. A fresh drip lifts in minutes, but oil left for weeks soaks deep into paving. 1. **Cover the spill.** Pour cat litter, sawdust or dry sand over fresh oil and grind it in with your shoe. 2. **Wait.** Leave it for a few hours, or overnight for a large spill. 3. **Sweep and bag it.** Put the oily litter in a sealed bag for the general waste bin. 4. **Block the gully.** Put rags or a sandbag around any nearby road drain. 5. **Scrub.** Pour on hot water with a good squeeze of washing up liquid and scrub hard with a stiff brush for a few minutes. 6. **Rinse sparingly.** Use a bucket rather than a hose, and mop up the dirty water. 7. **Repeat or step up.** For old stains on paving, use a driveway oil remover and follow the label. On tarmac, avoid solvent degreasers and white spirit. They dissolve the bitumen that holds the surface together, leaving a soft, patchy area. Stick to washing up liquid or a product labelled safe for tarmac. If oil has also gone on the car’s carpet or seats, our post on [motor oil spills in a car](/blog/how-to-clean-motor-oil-spill-in-car/) covers the inside. ## How do you remove rust stains from concrete and paving? You remove rust stains with a rust remover made for concrete or paving, used sparingly and tested first. Most of these products are mildly acidic. They dissolve iron oxide but can also lighten or etch the cement around it. Test on a hidden corner and wait to see how it dries. Apply with a brush only to the stain, leave it for the time on the label and rinse with a small amount of water. Light marks from a bicycle or a metal bin may fade with a scrub of washing up liquid first. The Health and Safety Authority’s leaflet on chemicals at home sets simple rules. Read the label, keep products in their original containers and never mix chemicals. Wear gloves and eye protection with any rust remover. ## How do you get rid of moss on tarmac and block paving? You get rid of moss by scraping and brushing it off, then making the surface less damp so it does not return. Moss is shallow-rooted. A flat shovel lifts thick mats, and a stiff broom clears the rest. For block paving, run a patio knife along each joint to pull out moss and weeds. Marshalls notes that moss and weeds can damage the joints and make paving harder to maintain. On tarmac, brush with the grain of the surface and avoid digging into it. If it comes back, use a moss killer labelled for hard surfaces and follow the label exactly. Cutting back overhanging hedges and clearing gutters that drip onto the drive will help more than any product. North-facing Dublin driveways that never see sun through winter will always need a brush every few months. ## Should you pressure wash your driveway? Pressure washing works well on block paving and concrete if you use the right angle and pressure. Marshalls advises holding the lance at 30° and spraying diagonally on medium pressure. Going harder can mark some paving and break up the jointing sand, which then needs re-sanding. Tarmac needs more care. High pressure can strip the fine stones from the surface and leave it looking worn. Use a wide fan nozzle on a low setting, or a surface cleaner attachment, and keep the nozzle moving. Basic safety applies every time: - Wear eye protection and closed shoes or boots. - Never point the lance at people, pets or windows. - Plug an electric washer into an outdoor socket with RCD protection, and keep the plug and cable dry. - Read your machine’s manual before choosing a setting. After washing block paving, let it dry fully, then brush kiln-dried sand into the joints. ## How to stop cleaning chemicals reaching the drains Keep every cleaning product, oil and dirty rinse water away from the road gully, because that drain goes to a river. Dublin City Council explains that a home has two kinds of drain. The foul drain goes to a wastewater treatment plant, while the surface water drain carries rainwater to local rivers and streams. Dublin City Council inspects drains under the Water Pollution Act 1977 to limit pollution of rivers and streams. Oil and degreaser washed off a driveway go the same way as rain. Block the gully with rags or a sandbag and use a bucket rather than a running hose. Soak up dirty water with sand or old towels. Dispose of oily litter and rags in a sealed bag. Take leftover chemicals and old engine oil to your local recycling centre rather than pouring them anywhere. ## Mistakes to avoid when cleaning a driveway Most driveway damage comes from too much pressure or the wrong chemical. Avoid these: - **Bleach on paving.** It can mark coloured blocks, harm plants and run straight into surface water drains. - **Solvents on tarmac.** They soften the bitumen binder. - **Pressure washing too close.** It etches the surface and blasts out joint sand. - **Washing in frost.** Water left in joints can freeze and damage the paving. - **Mixing products.** The HSA advises never to mix chemicals. - **Hosing stains into the road.** Oil and cleaner go to the nearest river. If building work left cement splashes or dust on the drive, scrape them off before washing, while they are small. Builders’ dust gets walked inside too, and our [after builders cleaning](/after-builders-cleaning/) deals with the house once the trades leave. Call 01 230 8646 to book an indoor clean once the outside is done. Want a fixed price instead? Call 01 230 8646. Give us the bedrooms, bathrooms and area, and we will give you a price on the phone. [01 230 8646](tel:+35312308646)[Request quote](/contact/) ## Frequently asked questions What is the best way to remove oil from a driveway? Cover fresh oil straight away with cat litter, sawdust or sand and leave it for a few hours to soak up. Sweep it into a bag for the bin. Then scrub with hot water and washing up liquid using a stiff brush. Older stains need a driveway oil remover used as the label directs. How do I get rid of moss on tarmac? Scrape off thick moss with a flat shovel or patio knife, then brush the surface with a stiff broom. Use a moss killer labelled for hard surfaces if it returns, following the label. Go easy with a pressure washer, because high pressure can strip the fine stones from the tarmac surface. Can I use bleach to clean my driveway? It is best avoided. Bleach run-off can reach surface water drains, which Dublin City Council says carry water to local rivers and streams. It also harms lawns and plants beside the drive and can mark coloured paving. Washing up liquid, a stiff brush and a product made for paving are safer. Will a pressure washer damage block paving? It can if used too close or too hard. Marshalls advises a 30° angle, sprayed diagonally on medium pressure. Otherwise you can mark some paving and wash out the joint sand, which then needs re-sanding with kiln-dried sand once the drive is fully dry. How do I remove rust stains from concrete or paving? Use a rust stain remover made for concrete or paving, and test it on a hidden corner first, because acid-based products can lighten or etch the surface. Work it in with a stiff brush, rinse with a small amount of water and stop run-off reaching the road drain. Does Dublin Cleaners clean driveways? Driveway washing is not one of our listed services. Our teams clean inside homes, offices and rentals. For a driveway, use the steps in this guide or a specialist with a surface cleaner and a way to collect run-off. We can deep clean the house once the outside work is done. ## Sources 1. [Marshalls, How to clean block paving](https://www.marshalls.co.uk/gardens-and-driveways/blog/how-to-clean-block-paving) (2026-11-14) 2. [Dublin City Council, Misconnection programme](https://www.dublincity.ie/residential/environment/protection-water-bodies/water-pollution-control/misconnection-programme) (2026-11-14) 3. [Health and Safety Authority, Use chemicals safely at home and in the garden](https://www.hsa.ie/media/1nfngryi/use-chemicals-safely-at-home-and-in-the-garden.pdf) (2026-11-14) ![Lana, founder of Dublin Cleaners](/img/lana-founder-dublin-cleaners-192.webp) About the author: [Lana](/author/lana/) Founder of dublincleaners.ie, Lana's company brings expertise in both residential and commercial cleaning services fostering a clean, healthy environment. Outside of work, you'll often find her hitting the gym or immersing herself in invigorating body balance classes.