How to Clean Block Paving, Patios and Driveways
Block paving looks sharp when it is new, but moss, algae, tyre marks and weeds soon creep into the joints. Cleaning it properly takes more than a quick blast with a jet washer. This guide covers how to clean block paving step by step, how to jet wash a patio or driveway without damage, and how to stop moss coming straight back.
What You Need to Clean Block Paving
- A pressure washer with a 25 degree nozzle or a patio surface cleaner
- A stiff broom and a weeding tool for the joints
- A patio cleaner or moss treatment suitable for paving
- Kiln dried sand for re sanding the joints
- A garden hose, safety glasses and sturdy boots
How to Clean Block Paving Step by Step
Step 1: Clear and sweep
Move cars, pots and furniture, then sweep away loose leaves and grit. Dig out weeds and thick moss from the joints with a weeding tool so the jet washer is not doing all the work.
Step 2: Treat stains and algae
Apply a paving cleaner or moss treatment to green and black patches and leave it for the time stated on the label. Treat oil marks separately with a degreaser made for paving.
Step 3: Jet wash at a low angle
Use a 25 degree nozzle or a surface cleaner at around 2,000 to 2,500 PSI. Hold the lance about 30cm away and spray at a shallow angle, working across the blocks rather than straight down into the joints. Our guide to jet wash nozzles and PSI explains the settings in more detail.
Step 4: Rinse and let it dry
Rinse the dirty water towards a drain or gravel area, then leave the paving to dry fully. In most weather this takes 1 to 2 dry days.
Step 5: Re sand the joints
Brush kiln dried sand into the joints until they are full, sweep off the excess and top up again after a few days as the sand settles. Full joints lock the blocks together and make it harder for weeds to take hold.
Step 6: Seal if needed
A paving sealer slows staining and makes the next clean easier. Apply it only to clean, dry paving and leave it for the full drying time before you drive on it.
How to Jet Wash a Patio
Patios vary more than driveways, so the method depends on the material.
- Porcelain: a 25 or 40 degree nozzle. Porcelain does not absorb water, so most dirt sits on the surface and lifts easily.
- Concrete slabs: a 25 degree nozzle or a surface cleaner. Concrete can take higher pressure.
- Sandstone and limestone: a 40 degree nozzle at low pressure, letting a stone safe patio cleaner do most of the work, as soft stone marks easily.
- Indian stone: low pressure only, and always test a hidden corner first.
Work from the house outwards so dirty water runs away from walls and doors, and finish with a full rinse to avoid streaks.
How to Clean a Tarmac or Concrete Driveway
Tarmac driveways
Tarmac is softer than it looks. Use a 25 or 40 degree nozzle at a lower pressure, avoid hot days when the surface softens, and never hold the jet in one spot. A degreaser helps with oil marks.
Concrete driveways
Concrete can take more pressure. A turbo nozzle or surface cleaner shifts ingrained dirt and tyre marks, and a hot water machine works best on old oil stains.
How to jet wash a driveway without stripes
Keep the lance moving in overlapping strokes at the same distance, or use a surface cleaner. Stripes appear when the distance between the nozzle and the ground keeps changing.
How to Stop Moss Growing on a Patio or Driveway
- Re sand the joints fully after every clean, as moss grows fastest in half empty joints.
- Apply a moss treatment after cleaning and again in autumn.
- Cut back overhanging branches so more light and air reach the surface.
- Sweep regularly so leaves do not rot down in the joints.
- Check drainage so water does not pool on the paving.
- Seal the paving to make it harder for spores to settle.
When to Call a Professional
Cleaning a small patio yourself is a manageable weekend job. For large driveways, old natural stone, heavy oil staining or paving that needs re sanding and sealing, professional jet washing saves time and avoids costly damage to the surface.
Block Paving Cleaning FAQs
How do you clean block paving without a pressure washer?
Use a stiff broom, a bucket of warm water and a patio cleaner suitable for block paving. Dig out weeds and moss from the joints first, scrub the cleaner in, leave it for the time on the label, then rinse with a hose. It takes longer than jet washing but avoids washing out the jointing sand.
How often should you clean block paving?
Most block paving needs a full clean once a year, usually in spring. Shaded, north facing or tree lined areas may need it twice, as moss and algae grow faster where the surface stays damp. Sweeping every few weeks and treating moss early keeps the yearly deep clean much easier.
Do you need to re sand block paving after jet washing?
Usually yes. Jet washing loosens and removes some of the sand between the blocks, even when it is done carefully. Brush kiln dried sand into the dry joints, sweep off the excess and top up again after a few days. Full joints keep the blocks stable and slow weed growth.
Can you jet wash a sandstone patio?
Yes, but only at low pressure. Sandstone is soft and marks easily, so use a 40 degree nozzle, keep the lance well back from the surface and let a stone safe patio cleaner do most of the work. Test a hidden corner first, as older sandstone can lose its surface layer.
What is the best time of year to clean a driveway?
Spring is the best time for most driveways, as it removes winter grime and moss before the growing season. Late summer also works well. Avoid freezing weather, as water left in the joints can freeze and lift the surface, and avoid very hot days for tarmac, which softens in the heat.
