The main cause of sinking in a block paving driveway is erosion of sand from the joints between blocks. As this happens the interlock between blocks is weakened and so the blocks begin to sink. This problem can be compounded by vehicles turning on the blocks.
Occasionally, sinking is caused by a poorly constructed sub base and if this occurs it may be necessary to re install a whole driveway as but the main cause is usually just joint erosion.
Block paving repairs – Causes of Joint Erosion
The stability of a block paving surface is dependent on the presence of compacted sand in its joints to provide and maintain the blocks to interlock.
It is best not to use a pressure washer too much on a block paved driveway. The jointing sand between the bricks will wash away.
When a lot of surface water runs frequently down the driveway, the jointing sand between the blocks will wash away. This gives the same problem as with overuse of a power washer, where the individual bricks become loose which could lead to sinking in parts of your driveway.
Block paving repairs – Where to Begin
It’s best to sort out areas that have lost sand between the joints first. Regular inspections to ensure all joints are in good condition is an ideal preventative measure. If sand has eroded it is important to infill these areas. If this is not enough and sinking continues further action will be required.
Lift the blocks in the affected area. Once a start is achieved by lifting one block the other blocks will lift easily. Specialist tools are available to lift the initial block but other tools such as chisels can also be used.
All removed blocks need to be thoroughly cleaned and old sand removed from area.
On the basis that there are no structural issues with sub base new sharp sand can be laid over area that blocks have been removed from and this is then compacted with attention paid to the gradient and leveling.
Blocks can then be re laid and compacted. If there are gaps of more than 5mm it may be necessary to cut some new pieces from similar looking blocks. This is better than just in filling with sand.
Jointing when the area is completely dry is then carried out using kiln dried jointing sand.
Block paving repairs may also be necessary if there has been an oil, petrol or diesel spill on a driveway. The same procedure as outlined above should be followed.
Though it’s best to have repairs carried out sooner rather than later, it’s practically impossible to get a colour match. Usually, the older your existing driveway is, the bigger the colour difference. Of course, if a repair is too daunting or simply not cost effective why not look at….
There are a wide range of paving choices available and remember to consider environmentally friendly options such as….
If you need a quality block paving repairer don’t hesitate to contact us
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