Block Paving Repair and Cleaning in North Devon: Fix Sunken, Weedy and Stained Driveways
Block paving is one of the toughest driveway surfaces there is, yet almost every older block paved driveway in North Devon shows the same handful of complaints: moss in the joints, weeds pushing through, a dip where the car sits, and blocks that have started to rock. Most of these problems are fixable, and many are preventable. This guide explains how to clean, re sand, seal and repair block paving, and how to tell a simple tidy up from a job that needs a groundworker.
Crabb Contractors Ltd has been laying and repairing paving across Ilfracombe since 1962. We have lifted driveways laid in the 1980s that looked tired on top but were perfect underneath, and we have lifted three year old ones that failed completely. The difference is almost always what is below the blocks.
Quick Answer: Can Block Paving Be Repaired?
Short answer: Yes. Block paving is made of individual units, so damaged, stained or sunken areas can be lifted, corrected and relaid without replacing the whole driveway. Weeds, moss and faded colour are usually fixed by cleaning, re sanding and sealing. Sunken or rocking blocks point to a problem with the sub base or drainage beneath, which needs the area lifted and rebuilt.
Which fix suits which problem
Problem | Likely cause | Usual fix |
Moss and green algae | Shade, damp, organic debris | Clean, treat, re sand |
Weeds in joints | Joint sand washed out, seeds settle | Clean, re sand with polymeric sand |
Stains and oil marks | Vehicles, leaves, food spills | Degrease, clean, seal |
Faded colour | Weather, UV, past pressure washing | Clean and seal |
Loose or rocking blocks | Joint sand lost, edge restraint failing | Re sand, reset edges |
Sunken patch or dips | Sub base failure, drainage, tree roots | Lift, rebuild base, relay |
Ponding water | Wrong falls, blocked drain | Re level, fix drainage |
Why Block Paving Goes Wrong
Block paving is a flexible surface. It works because compacted stone and sand beneath it spread loads, while the blocks lock together through the sand in the joints. Take away either part and it starts to move.
The sub base is too thin or poorly compacted. Most failures trace back here. If the stone layer was not dug to the right depth, was laid in one thick layer, or was not compacted properly, it settles under traffic. Cars then press the blocks down along the wheel tracks.
Water gets where it should not. Soft ground and trapped water weaken any base. North Devon gets plenty of rain, and a driveway with no way for water to leave will soften from underneath.
The edge restraint fails. Block paving needs solid edges, usually concrete haunching with kerbs, to stop it spreading. Without them the blocks drift apart and lose interlock.
Joint sand is lost. Rain, brushing and jet washing wash sand out. Without it, the blocks rock and weeds take hold.
Tree roots and services. Roots lift blocks, and old trenches for pipes and cables settle over time.
We cover how the layers fit together in our guide to reliable block paving contractors in Ilfracombe, and how digging out affects the result in excavation for driveways and groundwork.
How to Clean Block Paving Properly
Cleaning is the first step in nearly every repair, and it is where most people do accidental damage.
What you will need:
A stiff broom
A garden hose
A suitable block paving cleaner or biocide for moss and algae
A pressure washer with a fan nozzle, used carefully, and a rotary surface cleaner if you have one
Kiln dried jointing sand or polymeric sand for afterwards
Protective gloves and eye protection
Step by step
Clear the surface. Remove furniture, plant pots and loose debris. Brush off leaves and soil.
Remove weeds by hand. Pull larger weeds out by the root. A narrow knife or a weeding tool helps with joints.
Apply a moss and algae treatment. Follow the product instructions. Some need to be left to work for several hours, ideally on a dry day.
Wash with moderate pressure. Keep the lance moving, keep it a safe distance from the surface, and avoid directing a narrow jet along the joints.
Rinse and let it dry. Leave the surface to dry completely, often a day or two in damp weather, before re sanding.
A warning about pressure washers. High pressure is the main reason block paving looks worse after cleaning. A narrow jet strips sand out of the joints in minutes and can etch the face of the block, leaving a rough, pale and patchy finish. Use a wider fan, lower pressure, and clean in steady overlapping passes.
Re Sanding: The Step Most People Skip
Once the paving is clean and dry, the joints will be partly empty. Filling them is what stops weeds, and what locks the blocks together again.
Kiln dried sand. A plain, fine, dry sand is swept into the joints repeatedly until they are full. It is simple to use, but it can wash out again and weeds can return.
Polymeric sand. A fine sand mixed with a binding agent. After sweeping in, a light mist of water activates the binder, and the joints set firm but stay slightly flexible. It resists weeds, ants and washout much better than plain sand.
How to do it:
Spread the sand over a completely dry surface.
Sweep it across in different directions until every joint is full to just below the block edge.
Compact the surface lightly if you can, using a plate compactor with a rubber mat, to settle the sand.
Sweep again to top up the joints.
Brush the surface clean. Leftover sand on top of polymeric products can leave a hazy film.
Follow the product instructions for any water activation, and avoid rain for the stated period.
Sealing Block Paving: Is It Worth It?
Sealant is a coating applied to the surface after cleaning and sanding. It is not essential, but it helps in some situations.
Reasons to seal
Enhances the colour of the blocks, especially older ones that have faded
Protects against oil and food stains
Helps lock the joint sand in place
Makes future cleaning easier
Reasons to be cautious
Some sealants make the surface slippery when wet, especially on sloped driveways, which matters in Ilfracombe where many drives are steep
A poor quality or badly applied product can peel, turn cloudy or look patchy
The surface needs resealing every few years, depending on the product
You cannot seal over damp paving, and trapped moisture causes white cloudy patches
Choose a breathable, matte or satin product, apply it in thin even coats in dry weather, and test a small area first. For steep driveways, ask about anti slip additives.
Common Block Paving Repairs
Replacing Cracked or Stained Blocks
A single damaged block can be removed and replaced. The surrounding blocks are carefully loosened with a flat tool, the damaged block is lifted out, and a matching one is set into the same bed of sand and tapped down level. Colour matching can be difficult on older driveways, because original blocks fade. Blocks from the same driveway, taken from a hidden corner, make the best replacements.
Re Levelling Loose or Rocking Blocks
If blocks move underfoot but have not dropped, the bedding sand may have eroded or drained out. The affected area is lifted, the laying course is topped up and levelled, and the blocks are relaid and compacted. Re sanding finishes the job.
Rebuilding Sunken Areas
Sunken wheel tracks, dips near the garage door, and a trough along the line of a trench are the signs of a failed base. Topping up sand under the blocks is a short term fix at best, because the layer below is still moving.
A proper repair means:
Marking out and lifting the blocks over the whole affected area plus a margin.
Stacking and cleaning the blocks for reuse.
Digging out the failed laying course and weak sub base.
Finding and fixing the cause. This could be a leaking pipe, poor drainage, or soft ground that needs a geotextile and extra stone.
Rebuilding the sub base in compacted layers.
Laying a fresh bed of sharp sand and screeding it level.
Relaying the blocks, cutting where needed, and compacting.
Sweeping in sand and compacting again.
The area then blends back into the rest of the driveway, and the repair should last as long as the original was meant to.
Fixing Failing Edges
If the edge restraint has moved, blocks along the border drift outwards. This needs the edge reset with a proper concrete bed, and the adjoining blocks relaid.
Dealing with Ponding Water
Puddles that sit on a block paved driveway after rain mean falls are wrong, a drain is blocked, or an area has sunk. A level survey shows how water should move. The fix may be as small as clearing a channel drain, or as big as lifting and re profiling a section. Our article on why proper drainage installation matters for driveways in North Devon explains what to look for.
Weeds and Moss: Keeping Them Away
North Devon's mild, damp climate suits moss and weeds. A few habits make a big difference.
Keep the joints full. Empty joints collect windblown soil and seeds.
Sweep regularly. Leaves, soil and grass clippings break down and feed moss.
Cut back overhanging branches. Shade keeps surfaces damp and green.
Treat early. A biocide applied in autumn and spring slows regrowth.
Avoid scraping joints with metal tools. That removes sand and leaves a gap for new weeds.
Keep gutters and downpipes clear. Overflowing water stains and softens ground.
Is It Repair or Replacement?
Most block paving can be repaired. Replacement makes sense in a few cases:
More than a third of the surface is sunken or uneven
The whole driveway has been laid without a proper sub base
The blocks are crumbling or have lost their face
You want to change the layout, level or surface type altogether
In some cases homeowners decide to switch surfaces entirely. Our driveway surfacing comparison for North Devon explains how block paving compares with tarmac, resin and gravel.
When a driveway needs a bigger change, planning rules can apply. If you are widening the entrance, changing the front garden surface or adding a crossing, read our guide to driveway planning permission and dropped kerbs in Devon.
When to Call a Groundworker
Some jobs are fine for a confident DIYer with a weekend. Others need a team with machinery.
You can usually handle:
Weeding, cleaning and re sanding
Applying sealant to a small area
Replacing one or two blocks
Call a professional for:
Sunken areas wider than a metre or two
Recurring dips in the same place
Water pooling or running towards the house
Cracked kerbs or edges that have moved
Tree root damage
Any repair that needs lifting a large area, compacting a base, or digging out soft ground
Professional groundwork brings the right plate compactors, mini diggers and sub base materials, plus the experience to read what the ground is doing. Our groundwork contractors can assess what is wrong, and our brick paving and driveways team handles the relaying. If you only need a machine and an operator for a day, see our digger hire with driver service.
Seasonal Care Calendar for North Devon
Timing matters, because damp coastal weather limits when you can clean, sand and seal.
Spring: Clean after winter. Treat moss, re sand, and check edges for movement. Dry spells in April and May are ideal for sealing.
Summer: Best time for repairs and relaying. Dry ground makes compaction easier. Book early, because summer is the busiest period for groundwork. Our guide to the best time of year to book a driveway or groundwork project in North Devon explains how the calendar works.
Autumn: Clear leaves promptly. Treat moss before the wet months. Check drainage channels and gullies before heavy rain.
Winter: Avoid pressure washing in freezing weather, because water in the joints can freeze and shift blocks. Use grit rather than rock salt where possible, since heavy de icing salt can harm some surfaces.
Protecting Your Driveway Long Term
A few small changes make a driveway last decades.
Do not park heavy vehicles, skips or delivery lorries on areas not designed for them.
Keep tree roots in check, and avoid planting large trees close to the driveway.
Fix leaks promptly, whether from a downpipe, tap or pipe.
Check the edges annually.
Top up joint sand every year or two.
Plan the drainage when you plan the surface. Water is the enemy of every driveway.
If you are weighing up repair versus a rebuild on a sloped plot, our article on sloped and uneven gardens in North Devon explains how ground levels change the approach.
What We Look For on a Repair Visit
When we visit a block paved driveway in Ilfracombe, we walk it before we lift anything. We look at where the water goes, how the surface behaves under foot, and what the edges are doing. We check for signs of old trenches, tree roots and previous repairs. Often the cause of the problem is not where the damage shows. A dip near the garage door might start with a blocked gully ten metres away.
Sixty years of working on North Devon ground helps here. The clay, shillet and slate we dig through do not behave like the sandy soil in many driveway guides, and our repairs reflect that. You can read more about our approach in what six decades in North Devon groundwork means for homeowners.
Related Guides From Crabb Contractors
Keep reading: our guides to building a concrete base for a garage, shed or extension, soakaway and land drainage installation. For help on site, see our groundwork contractors and brick paving and driveways pages.
Frequently Asked Questions
How often should block paving be cleaned and re sanded? Clean it at least once a year, and top up the joints every one to two years. Shaded or damp driveways may need attention more often.
Is it safe to pressure wash block paving? Yes, if you use moderate pressure, a wide fan nozzle and a steady technique. A narrow, high pressure jet will blast sand from the joints and can damage the surface.
What is the best sand for block paving joints? Polymeric sand lasts longer and resists weeds better than plain kiln dried sand. It needs a dry, clean surface and careful activation.
Why has my block paving sunk in the middle? Usually the sub base has failed, or water has softened the ground below. Topping up sand will not hold. The area needs to be lifted and rebuilt on a stable, drained base.
Can I lay new blocks over old block paving? No. New blocks need a proper compacted base and bedding layer. Laying over old paving hides problems and creates height issues at doors and drains.
Can Crabb Contractors repair block paving in Ilfracombe? Yes. We repair and relay block paving across Ilfracombe and North Devon, including sunken areas, failing edges and drainage problems.
Keep Your Block Paving Looking Right for Years
Block paving rewards a little regular attention. A clean surface, full joints and clear drains protect the base underneath, and a base that stays dry and compacted keeps blocks flat for decades. When something does go wrong, lifting and rebuilding the affected area is almost always less disruptive than starting again.
If your driveway in Ilfracombe or North Devon is sunken, loose or just tired, call Crabb Contractors on 01271 500072 or get in touch online. We will visit, find the cause, and tell you honestly whether a clean and re sand will do or whether the base needs attention.
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