Block Paving Technical Guidance

Block Paving Cleaning and Maintenance

If neglected, even the best, perfectly installed driveway will eventually deteriorate in appearance and performance. Keeping paving in optimum condition requires only a little effort and relatively simple techniques whether it is keeping new paving looking good or giving old neglected paving a new lease of life.



For further information please take a look at our Literature section for our Cleaning and Maintenance Block Paving Factsheet.

  • Initial cleaning & maintenance on new driveways

    For the first month or so of laying block paving, it is recommended to restrict cleaning and maintenance to the straightforward sweeping of debris, leaves and other build up.

    vigorous cleaning. For this reason, avoid the use of pressure washers or vacuums which could easily remove the jointing material and in turn detrimental to the performance of the paving.


    During this period the joints should be topped up with jointing sand by simply brushing the sand cross the pavers and into the joints having first cleaned the paving so as to avoid brushing any debris into the joints which may provide a future foothold for moss or weeds.


    With a few simple cleaning and maintenance techniques, your paving patio or driveway can be kept in optimum condition.

  • General cleaning and care

    No matter how well constructed a driveway is if it is neglected then detritus will build up and weeds, moss, algae and lichen is likely to establish itself. Therefore, routine cleaning on a seasonal basis is recommended as follows:

    On dry paving use a stiff bristled brush to remove any dirt or build up from the surface.

    • Pull out, scrape off any weeds and moss.
    • Using soapy water (basic washing-up liquid or a non-acid based detergent will suffice) and a stiff bristled yard brush, scrub the paving surfaces and hose down with clean water.
    • Unless the paving a heavily stained or soiled, a pressure washer should not be required.
    • Some of the jointing sand may be inadvertently removed during the cleaning which will need replacing by brushing in new sand once the paving has been allowed to dry out.

    Acid-based chemical cleaners: these products can etch the paving surfaces and affect the pigmentation of the blocks permanently ruining the paving. We recommend that these cleaning products are avoided wherever possible and only used if absolutely necessary!

  • Weeds

    Any block paving can suffer from weeds if it is neglected and not routinely cleaned. Paving claiming to be “weed-free” is misleading as weeds do not grow through paving blocks themselves or through the sub-bases with the exception of extreme species such as Japanese Knotweed.


    Weeds usually establish themselves in the joints and regular cleaning and care as detailed above will keep them at bay. Replace any jointing sand which may have been pulled out with the weed roots. Weed-killers: Regular brushing will tend to keep weeds away but in badly affected areas the selective use of contact or systemic weed killer is effective and should not damage the paving blocks. Use sparingly and always follow the manufacturer’s instructions.

  • Efflorescence

    Efflorescence is a visual effect which can appear on the surface of a concrete product in the form of a white crystalline or hazy deposit. Efflorescence is the leaching out of natural salts from the paving blocks, the sub-base and jointing materials which is completely harmless and will fade and disappear over time.


    On dry paving, the efflorescence can be brushed away with a stiff bristled brush, swept clean and rinsed off using a hosepipe. The efflorescence will reocur until the salts are used up and will fade and cease permanently.

    See our Efflorescence section for more information.

  • Algae

    Damp, shaded areas are more prone to the growth of algae but can be easily dealt with as follows:

    • Using a diluted bleach mixture (thin household bleach mixed 1:1 with water), treat the affected areas and leave for a few minutes.
    • Thoroughly rinse off with clean water.
    • This process may need repeating several times. Performing this treatment every few months will deter further growths.
  • Tyre marks and general scuffs

    Tyre marks and general scuffs will be removed naturally through weathering although scrubbing the affected area with warm soapy water or careful power washing should remove these marks quite readily.

  • Oil & grease stains

    Oil can penetrate the blocks so must be removed a quickly as possible:

    • Absorb as much oil or grease using paper towels or cloths.
    • For soaked-in stains scrub the area with soapy water and rinse with hot water. This may need repeating a number of times.
    • For more stubborn stains a degreaser product may need to be used being cautious of the possibility that the pigmentation of the block may be affected.
  • Moss

    Moss does not penetrate the paving and sits on top of any dirt or debris above the paving joint and is easily removed. Scraping and scrubbing is the most effective way of removing moss.

    Moss-killing chemicals

    There is evidence that some ‘moss-killing’ chemicals can actually discolour paving especially if they contain ferrous sulphate. Use with caution and test on an inconspicuous area first.

  • Lichen

    Unlike moss, lichen does penetrate into the block surface and is far more difficult to remove than moss or algae. Lichen tends to be in the form of white/grey circular spots but can sometimes be darker in colour. Regular general cleaning will keep lichen growth at bay but should it take hold can be dealt with as follows:

    • Use a proprietary fungicidal solution or a bleach/water mixture to treat the area.
    • Leave for several minutes.
    • Scrub the area with a stiff-bristled brush.
    • Rinse thoroughly and repeat as necessary until the lichen has gone.

    Vigorous scrubbing can scratch the block surface and leave lasting marks and the lichen itself can leave behind marks which cannot be shifted. Therefore, regular cleaning and treatment is the best way to avoid the establishment of lichen and subsequent permanent altering of the appearance of the paving surface.

  • Rust spots

    There are proprietary products for the removal of rust stains on concrete which should be used in strict accordance with the manufacturer’s instructions.


    Diluted solutions of hydrochloric acid can be used although this must be used with extreme caution as it etches the surfaces of the paving blocks and poses a personal safety risk if used incorrectly. We advise seeking specialist advice and avoid using acid solutions wherever possible!

  • Power washers

    Power washers are an excellent cleaning aid but should be used sparingly as repeated exposure to powerful jets can deteriorate the surface of the blocks over time. The jets can remove the jointing sand from between the blocks which must then be refilled and pointed after each use.


    Our preferred cleaning method is for sweeping and general cleaning as little and often and the careful use of a power washer only when necessary on a seasonal basis.

  • Sealants

    Sealants are available for block paving which can be sprayed or brushed on to seal the paving and joints. This skin provides an effective barrier to weeds and stains and can enhance the appearance of the paving. Sealants should be applied by specialists and only after the paving has fully settled.


    It is important to ensure that all instances of efflorescence have been exhausted otherwise there is a risk of ‘trapping’ the visible efflorescence under the sealant with no chance of removing it.