Power washing cobble block driveways and paths

Cobble block driveways and paths fit in well with most gardens and look great when first installed. As time passes they slowly start to be colonised by algae and lichens on the surface, with moss and weeds filling the joints. That once pristine path or driveway no longer looks as neat as it once did, it is time for a power washing service.

With the right techniques, equipment and chemicals, any tired looking driveway can be restored. Let me take you through my process of power washing cobble block paving.

  • Step 1, the driveway or paths are cleared of any debris such as leaves, twigs and any other rubbish that might have blown in to the garden.
  • Step 2, if the driveway is nasty and green with plenty of algae contamination I might first pre-treat the surface with a softwash solution to lift and soften up the lichens. This will also help remove much of the algae instantly. If the drive is not in poor condition I’ll skip the pre-treatment and go straight to step 3.
  • Step 3, is where the power washing begins. The condition of the substrate to be cleaned is assessed and the correct level of pressure set on the machine. The edges of the driveway or paths are now washed using a lance fitted with a turbo nozzle. This really helps lift the weeds and old sand from the joints.
  • Step 4, I now use a flat surface cleaner to methodical clean the main body of the cobble block driveway. The flat surface cleaner can clean a strip 18 – 20 inches wide in one single pass. This reduces the fatigue on the operator and helps keep down the mess from splatter.
  • Step 5, the driveway is now swept to gather up all the moss, weeds and sand removed from the joints during the cleaning and is now washed down using the lance again.
  • Step 6, for that extra little zing on a driveway, I like to post treat the blocks once more with the softwash solution and then rinse down after a 20 minute dwell time. This just adds that extra little sparkle to the driveway.
  • Step 7, once the driveway has dried sufficiently, the joints are re-sanded using kiln dried sand. This helps with the stability of the driveway and completes the overall look and finish. (sanding can be often completed same day during a hot summer, but is more usually done a couple of days after)