Block Paving and Driveway Cleaning a Basic Introduction

There is currently a wide range of cleaning materials, products and equipment that are suitable for cleaning block paving, paths, patios and driveways. They range from scrapers, brooms, brushes and cleaning agents, to power washers which include those fixed to the end of a hose being water pressure powered to electrical or mechanical petrol or diesel powered pumps. Some with potentially high pressures capable of doing more harm than good when incorrectly used for cleaning on block paving.

There is a multitude of cleaning machines purposely designed and built specifically for the block paving and driveway cleaning market. Gone are the days of hours spent with a lance cleaning a driveway by hand individually jet washing clean each block by block only to finish with a stripy non uniform finish. Now are the times of self propelled rotary cleaners that give a consistent and thorough or deep cleaned finish as it is now called to any paving surface or driveway.

By using this range of equipment most unsightly marks such as mud, dirt, horticultural stains, weeds, moss and slippery algae can be comprehensively removed and any hard surface can be catered for including the cleaning of:

·         Block paving and block paved driveways

·         Patios and paths

·         Slabwork and flagstones

·         Concrete and pattern imprinted concrete

·         Tarmac

·         Stone & brick walls

·         Decking

·         Hard surface sports pitches

A simple cleaning  of any block paving and driveways can always be carried out by giving them a good sweep with a stiff broom to remove any debris, followed by a wash with a proprietary cleaner a hose down after and a quick sanding to replace any lost jointing sand from the cleaning process.

For a more severe clean or for larger areas such as driveway cleaning a power washer can be engaged. A small domestic electric pressure washer connected to a hose can be a useful tool for the removal of weeds and moss that have taken hold in the jointing sand along with cleaning away any dirt and grime.

Prior to any cleaning the area should be swept clear to avoid any surface rubbish becoming a hazard during cleaning. If using a lance it should be kept at a shallow angle to the paving the nozzle of the lance can be adjusted to give the required jet of water sufficient to be effective and the distance it is held from the paving should be enough to clean effectively but without blasting out any jointing sand when cleaning block paving or any pointing when cleaning patios and slab work.

Care should be taken that any dislodged material such as pointing or any surface rubbish does not cause any damage if caught in the spray of the nozzle it can become blasted out in a missile like fashion.

Electric pressure washers now come with small rotary washers as part of the package that can be connected for use thereby reducing the need for the lance on the majority of the job. This will help remove the stripping effect obtained when cleaning a large area with a lance it will also contain a lot of the spray when cleaning block paving but they won’t get into the awkward corners. This is where a lance will have to be used and extreme care must be taken with the force of water when used in such a small environment.

For those large jobs such as driveway cleaning or commercial premises the professional’s choice of cleaning machine will be to use a larger diesel powered pressure washer these can produce extreme pressures of up to 3000 psi or more and can be of greater benefit than an electric powered machine.

However size is not necessarily beneficial more care has to be taken to not blast out jointing material especially when cleaning block paving. For the more powerful machines it could start to affect the sub base material if the force of water is that great that it washes away the jointing sand wand then permeates beneath the blocks in large quantities with potentially dire consequences. Another disadvantage to power washing is that it can damage paving. The pressure should be adjusted to be sufficient to give a good clean. Excess pressure can damage blocks causing them to break up particularly those cheaper blocks on the market. Some natural stone and flag stones can also be damaged by too high a pressure in that they can delaminate where the natural layers of compressed stone come away from each other as water is forced underneath the individual layers when cleaning.

Again with the use of the more powerful machines the jointing material must always be replaced especially for block paving where the sand is integral to the blocks strength as a whole and there is little point in cleaning paving only to allow areas where weeds will manifest themselves thus requiring further cleaning at a later date.

With regards any cleaning preparation as always is the key to a successful job.  The area should be swept first and thought given to the cleaning process. A note should be mentally taken of where any excess water will flow and the sequence of cleaning. All cleaning should be done systematically when cleaning block paving the pattern and landmarks such as building features can used to section off areas for cleaning. Once cleaned the area should  be washed or hosed down any excess water brushed away leaving a clean looking area.

Once block paving or any paving with jointing sand has been cleaned it should look allowed to dry thoroughly before any jointing sand is replaced or pointing undertaken If its slab work.

Pressure washing can not remove all marks or stains chemicals may need to be applied for the removal of oil stain like engine oil or fuel oils. Most pressure washers have the capability to automatically add detergents as they run by connecting the detergent inline to the pressurised water flow. Thus use of such degreasers can be a valuable to cleaning driveways of oil stains. Alternatively a pre-treatment oil displacing agent can be applied prior to cleaning.

Cement, tar and paint will have to be removed by manual methods prior to cleaning with a pressure washer.

Finally cleaning can truly bring back the glory to any paving especially bringing out the colours in natural stone or block paving. But it can only clean what is already there it cant return to new or restore colours that have faded through UV degradation over the years

Once cleaned it may well be worth investing in some form of protection for the paving as well as allowing for something that will offer future ease of cleaning. The remedy would be the provision of a block and paving sealer.