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How to Clean Block Paving: The Complete Guide

Updated February 2026 • 10 min read

Block paving is one of the most popular choices for driveways and patios in the UK, but it requires proper care to keep looking its best. This comprehensive guide covers everything you need to know about cleaning block paving – whether you're tackling it yourself or considering professional help.

Why Block Paving Needs Special Care

Block paving is different from solid surfaces like concrete or tarmac. The individual blocks are held in place by sand in the joints, which creates some unique cleaning challenges:

Step-by-Step Block Paving Cleaning

Step 1: Preparation

Before you start:

  • Move cars, plant pots, furniture and anything else off the paving
  • Sweep away loose debris, leaves and surface dirt
  • Note any damaged or sunken blocks that might need attention
  • Protect nearby plants if using chemicals

Step 2: Weed Removal

Remove weeds from the joints before washing. Options include:

  • Manual removal – Pull out weeds by hand or with a weeding tool
  • Weed killer – Apply 1-2 weeks before cleaning (follow product instructions)
  • During pressure washing – Some weeds will be blasted out, but roots may remain

Removing weeds first ensures a cleaner finish and prevents regrowth.

Step 3: Pre-Treatment (Optional but Recommended)

For heavy algae or moss growth, applying a biocidal treatment before pressure washing gives better results:

  • Apply moss/algae killer and leave to work (check product instructions)
  • This kills the growth at the root
  • Makes pressure washing more effective
  • Helps prevent rapid regrowth

Step 4: Pressure Washing

This is where technique really matters:

  • Pressure setting: 1500-2500 PSI is usually sufficient. Higher pressure risks damage
  • Nozzle: Use a 25° or 40° fan nozzle, or a rotary surface cleaner for best results
  • Distance: Keep the lance 15-30cm from the surface
  • Angle: Work at a slight angle, not straight down into joints
  • Pattern: Work in overlapping passes to avoid streaking
  • Direction: Work in the same direction throughout

⚠️ Common Pressure Washing Mistakes

  • Too much pressure – Blasts sand out of joints and can damage blocks
  • Too close – Creates etching marks and uneven cleaning
  • Inconsistent technique – Causes visible streaking and patchy results
  • Wrong nozzle – A zero-degree nozzle will damage the surface

Step 5: Re-Sanding Joints (Essential)

This step is crucial and often overlooked by DIYers:

  • Allow the paving to dry completely (24-48 hours in good weather)
  • Use kiln-dried sand (not building sand or sharp sand)
  • Spread sand across the surface and brush into joints
  • Brush diagonally to the joint lines for best filling
  • Repeat until joints are full
  • Sweep away excess

Sand stabilises the blocks and prevents movement. Without it, your paving will deteriorate.

Step 6: Sealing (Optional)

Applying a sealant after cleaning offers several benefits:

  • Locks sand into joints, preventing weed growth
  • Creates a barrier against algae and moss
  • Makes future cleaning easier
  • Enhances colour (wet look or matte options available)
  • Protects against oil stains and spills

Sealant typically adds £3-6 per m² but can extend the time between cleans from 1-2 years to 3-5 years.

DIY vs Professional Block Paving Cleaning

DIY Cleaning

Pros:

Cons:

Professional Cleaning

Pros:

Cons:

💡 Our Recommendation

For small areas or regular maintenance, DIY can work well if you're careful. For larger driveways, heavily soiled surfaces, or if you want guaranteed results, professional cleaning is worth the investment. We've seen too many DIY disasters where driveways end up looking worse – or structurally damaged – after incorrect pressure washing.

Maintaining Your Block Paving

After cleaning, these habits will keep your block paving looking good longer:

  1. Sweep regularly – Remove leaves and debris that trap moisture
  2. Treat weeds early – Pull them before they establish deep roots
  3. Address stains quickly – Oil, rust and other stains are easier to remove when fresh
  4. Check sand levels – Top up kiln-dried sand if you notice joints emptying
  5. Annual clean – A yearly maintenance clean is easier than a major restoration

Common Block Paving Problems & Solutions

Weeds Keep Coming Back

If weeds return quickly, sand levels are probably low. Top up sand and consider sealing to prevent seeds settling in joints.

White Staining (Efflorescence)

White marks appearing on new block paving are natural mineral salts. They usually fade over time but can be cleaned with specialist products.

Blocks Sinking or Moving

This indicates problems with the sub-base or lack of sand. May need lifting and re-laying – beyond the scope of cleaning alone.

Oil Stains

Fresh oil can be absorbed with cat litter. Old stains need specialist degreaser treatment. Sealing prevents future oil penetration.

Need Your Block Paving Professionally Cleaned?

Hulkzilla provides professional block paving cleaning across Somerset, including re-sanding and optional sealing. We have the right equipment and expertise for perfect results.

Call 07725 542334 Get a Free Quote

Summary

Cleaning block paving requires more care than solid surfaces due to the sand-filled joints. The key steps are: preparation, weed removal, optional pre-treatment, careful pressure washing with correct technique, essential re-sanding, and optional sealing. While DIY is possible, professional cleaning delivers better, longer-lasting results and avoids the risk of damage.

Whether you tackle it yourself or call in the professionals, regular cleaning will keep your block paving looking great and prevent the buildup that leads to expensive restoration work.