Block Paving in Kent: Why Wheel Tracks Start to Sink
Block paving in Kent is a great option for many homes due to its aesthetic appeal and ease of repair. However, the lifespan of your block paving will be dependent upon a variety of factors. Ground preparation, weight and quality of installation are key factors and much more important than the surface. Your drive may look fine, but the areas beneath your tyres will start to subside.
The tyres will always be on the same two areas. It is constructed by using multiple layers of materials. The blocks and joint sand are on top of the bedding layer, which is then on top of the compacted sub-base; this is then on top of the natural ground. This transfers the load across each layer.
How to determine if it is loose blocks or failed sub base
Using a straight edge (long spirit level), you can identify:
Loose blocks: Individual blocks will be loose, rocking or raised with no jointing sand. The depression is very small and patchy.
Edge/kerb: Edge restraints have gaps or are moving, causing the base to spread.
Water: Puddles will form in depressions, showing how deep the depression is. Can also indicate a drainage problem.
Blocks that are moving indicate a surface issue. If a few blocks are all sinking together, then there is likely a fundamental issue.
When to lift and relay
Lifting and relaying is used when the base is still solid. Usually this is because the depression is small and localised. Or there has been a loss of bedding sand or poor jointing. The contractor will lift the blocks, check the base, re-bed the area and then relay the same blocks. New jointing sand will be brushed into the joints and the surface will be compacted.
When to excavate and rebuild
If your base has failed, it makes sense to rebuild. Signs of a failed base would be deep depressions, previous repairs that have recurred, or a spongy surface. Once the blocks have been lifted, the contractor may find that there is a very thin sub-base or soft ground.
They will remove the blocks from the area and excavate the failed material. They will then rebuild the sub-base using compacted layers. New bedding will be added, and the blocks will be replaced. Only the affected area will be repaired, meaning the rest of your drive remains untouched. Although this will cost more to start with, it will fix the root cause, and you won’t be paying twice for the same repair.
Contact a local specialist in block paving in Kent to check the base.
