How to Clean and Restore a Block Paved Driveway

Block paving looks brilliant when it’s first laid — those crisp, uniform blocks with clean joints and rich colour. Fast-forward five years without maintenance and it’s a different story: weeds sprouting from every joint, moss covering half the surface, blocks sinking in patches, and the whole thing looking like it belongs on an abandoned estate.

The good news is that block paving can be restored to near-new condition with a weekend’s work and the right approach. I’ve done this on my own driveway and helped neighbours with theirs, and the transformation genuinely surprises people. Here’s the full process from weedy mess to finished result.

Why Block Paving Looks Terrible After a Few Years

Understanding why block paving deteriorates helps you fix it properly and prevent it happening again:

• Jointing sand washes out — rain, pressure washing (ironically), and foot/vehicle traffic gradually displace the sand between blocks. Without sand, the joints become open channels for weed seeds and water.
• Weeds and moss colonise — once the joints are open, seeds lodge in and germinate. Moss spreads across shaded areas. Within a couple of seasons, the weeds actually accelerate further sand loss as their roots push the remaining sand out.
• Blocks sink or shift — without jointing sand locking them in place, individual blocks can rock, sink, or move under vehicle weight. This creates uneven patches and trip hazards.
• Algae and grime build up — the surface accumulates dirt, tyre marks, oil drips, and biological growth that dulls the original colour.
• The original colour fades — UV exposure gradually fades the pigment in concrete blocks. Sealing prevents this, but most driveways are never sealed.

The restoration process reverses all of these problems systematically.

What You’ll Need

Gather everything before you start — this is a multi-step process and you don’t want to stop halfway through to go to the DIY shop.

• Pressure washer (2,000-3,000 PSI) with a surface cleaner attachment
• Block paving cleaner (dedicated product, not just detergent)
• Weed killer (glyphosate-based for existing weeds)
• Stiff broom or wire brush
• Kiln-dried sand (enough to fill all the joints — typically 1-2 bags per 10 square metres)
• Block paving sealant (optional but strongly recommended)
• Replacement blocks (if any are cracked or missing)
• A flat screwdriver or block paving lifter (for removing and replacing blocks)
• Rubber mallet
• Safety gear: goggles, waterproof boots, ear protection

Step 1 — Kill and Remove Weeds

Don’t skip this step. If you pressure wash over live weeds, you’ll blast the greenery off but leave the roots intact in the joints. They’ll regrow within weeks.

Two weeks before you plan to clean the driveway, apply a glyphosate-based weed killer to all the weeds growing through the joints. Glyphosate is a systemic herbicide — it travels down to the roots and kills the entire plant, not just the visible growth. You want the weeds completely dead (brown and withered) before you start cleaning.

For heavy weed infestations, a second application a week after the first ensures complete kill. Pay attention to the base of each weed — if there’s any green left at the root crown, it’ll regrow.

Once the weeds are dead, pull out or scrape out as much of the dead material as possible with a stiff wire brush or a specialised block paving weed scraper. This clears the joints for re-sanding later.

Step 2 — Apply Block Paving Cleaner

A dedicated block paving cleaner breaks down the moss, algae, and ingrained grime that a pressure washer alone would struggle with. This pre-treatment makes the pressure washing step dramatically more effective.

Apply the cleaner according to the manufacturer’s instructions — most are diluted with water and applied with a watering can or pump sprayer. Coverage is typically 3-5 square metres per litre of concentrate. Leave it to work for 15-30 minutes (don’t let it dry on the surface).

For oil stains: Apply a separate degreaser directly to oil spots and leave for 10-15 minutes. Scrub with a stiff brush before pressure washing. Old, deep oil stains may need a poultice treatment — apply a paste of cat litter or sawdust mixed with degreaser, leave overnight under plastic sheeting, then sweep up and pressure wash.

Step 3 — Pressure Wash (With a Surface Cleaner)

Now for the satisfying bit. Pressure washing block paving removes the loosened grime, dead moss, and remaining weed debris, revealing the original block colour underneath.

Settings: Use 2,000-2,500 PSI for standard concrete blocks. Higher pressures can pit softer blocks and blast out the remaining jointing sand faster than necessary. If you’re using a lance (wand) rather than a surface cleaner, use the 25-degree (green) nozzle and keep it moving.

Why a Surface Cleaner Makes a Huge Difference

I cannot stress this enough: if you’re cleaning any area larger than a small porch, use a surface cleaner attachment. A surface cleaner is a round housing with spinning nozzle bars underneath that provides even, consistent cleaning in a wide path.

The advantages over a lance/wand:

• No zebra stripes — the spinning action gives uniform coverage without the visible pass lines that a lance creates
• Faster — a 38cm surface cleaner covers a driveway in about a third of the time a lance takes
• Less sand displacement — the enclosed housing contains the spray, so less jointing sand gets blasted out compared to a direct lance
• Less mess — dirty water stays under the housing rather than spraying across your legs, walls, and car

Technique: Work methodically from one end to the other, overlapping each pass slightly. Direct the dirty water runoff away from cleaned areas. For stubborn spots, slow down and make a second pass rather than increasing pressure.

Let the driveway dry before moving to the next steps. You’ll be amazed at the colour difference — block paving that looked uniformly grey often reveals its original red, charcoal, or buff colour once the grime is removed. Allow at least 24 hours of dry weather before sanding and sealing.

Step 4 — Replace Loose or Sunken Blocks

With the driveway clean and dry, you can now see any blocks that are cracked, chipped, sunken, or raised. Fixing these before re-sanding and sealing gives a much better finished result.

Removing a block: Insert two flat screwdrivers (or a proper block paving lifter) into the joint on opposite sides of the block and lever it up. Once one block is out, adjacent blocks are easy to remove.

For sunken blocks:

1. Remove the affected blocks and the ones immediately surrounding them.
2. Top up the sub-base (sharp sand or grit sand) underneath and compact it with a hand tamper or a piece of flat timber.
3. Replace the blocks, tapping them level with a rubber mallet.
4. Check with a straight edge across the surrounding blocks — you want a flush surface.

For cracked or damaged blocks: If you have spare blocks from the original installation, swap them in. If not, try to source matching blocks — take a sample to your local builders’ merchant. Exact colour matches on aged paving can be tricky; placing replacement blocks in less visible areas and moving better-conditioned blocks to the prominent spots is a common trick.

Step 5 — Re-Sand the Joints (Kiln-Dried Sand)

This is arguably the most important step in the entire restoration. Refilling the joints with kiln-dried sand locks the blocks in place, prevents weed growth, and restores the structural integrity of the paving.

Why kiln-dried sand specifically? Kiln-dried sand is completely dry and fine-grained, so it flows into joints easily and compacts tightly. Damp sand clumps and won’t fill joints properly. Builder’s sand is too coarse. Play sand is too fine and washes out. Kiln-dried sand is the correct product — no substitutes.

Application:

1. Make sure the driveway is completely dry. Kiln-dried sand sticks to damp surfaces and won’t flow into the joints.
2. Pour sand onto the paving and sweep it into the joints using a stiff broom. Work in sections, sweeping back and forth in different directions to fill the joints from all angles.
3. Compact the sand by vibrating it into the joints — you can hire a plate compactor (vibrating plate) for large areas, or use a rubber mallet and a board on smaller driveways. Walk over the area to settle the sand further.
4. Sweep more sand into the joints to top up — they’ll settle after compacting.
5. Repeat until the joints are full — the sand should be within 2-3mm of the block surface.

How much sand do you need? As a rough guide, a 20-25kg bag of kiln-dried sand covers about 10-15 square metres, depending on joint width and depth. For a typical double driveway (around 30-40 square metres), you’ll need 3-5 bags. Buy an extra bag — it’s cheap and better to have too much than too little.

Step 6 — Seal the Block Paving (Optional but Recommended)

Sealing is optional, but having done driveways with and without sealant, I can confidently say: sealed block paving stays cleaner, keeps its colour, and resists weeds significantly better than unsealed paving. The sealant also locks the kiln-dried sand in the joints, preventing it from washing out again.

Wait for the right conditions: The paving must be completely dry (at least 24-48 hours after any rain) and the temperature should be above 10°C. Don’t seal if rain is forecast within 24 hours.

Application: Most block paving sealants are applied with a roller or pump sprayer. Apply two thin coats rather than one thick coat — this gives better penetration and a more even finish. Allow the first coat to dry (usually 4-6 hours) before applying the second.

Wet Look vs Matte Sealant

My preference: Wet-look sealant on faded paving that’s lost its colour — the transformation is dramatic. Matte sealant on newer paving where the colour is still good and you just want protection.

How Long This Process Takes

For a typical double driveway (approximately 30-40 square metres):

Total active working time: 8-12 hours spread over a weekend (plus the 2-week weed-killing lead time). The drying periods between steps mean this isn’t a single-day job — plan for a Friday evening start (cleaner application and pressure washing) and a Saturday or Sunday for sanding and sealing, weather permitting.

Recommended Block Paving Restoration Products

Here’s the full shopping list for a block paving restoration:

Cleaning:

• Block paving cleaner concentrate (5 litres covers most double driveways)
• A pump sprayer for applying the cleaner
• Glyphosate weed killer concentrate (apply two weeks ahead)

Equipment:

• A pressure washer rated at 2,000-3,000 PSI
• A surface cleaner attachment (38cm / 15-inch minimum)
• A stiff outdoor broom

Restoration:

• Kiln-dried sand (3-5 × 25kg bags for a standard driveway)
• Block paving sealant — wet look or matte (5-10 litres depending on area)
• A long-handled roller for applying sealant

A full block paving restoration takes a weekend’s effort and maybe £80-150 in materials. Hiring a professional to do it would cost £500-1,000+. The DIY result is every bit as good — and there’s a particular satisfaction in transforming something that looked awful into something that looks brand new.