About De Hoop     |     Brick Types & Products     |     Clay Brick Information     |     Contact Us
Language of Clay Bricks    |    Paving Maintenance & Cleaning    |     History of Bricks    |    Brick Articles


The Cape Grace Hotel, V&A Waterfront

The Table Bay Hotel, V&A Waterfront

The Cape Town Aquarium

The Cape Town Stadium

Iziko Cape Town Museum

St Georges Mall Cape Town

Sidewalks in City Centre

The Mount Nelson Hotel

Val De Vie Wine & Polo Estate Paarl

The Grand Roche Hotel Paarl

The “Rooi Plein” and sidewalks, Stellenbosch University Campus

The Knysna Waterfront
Thesen Island

Roads & Sidewalks in George



Clay Paver Maintenance

Basic Maintenance

Clay pavers require no special maintenance as natural weathering keeps most clay paving systems clean and beautiful. Pressure washers are not recommended for use on flexible base applications. The pressure washer tends to remove joint sand which compromises interlock. We suggest using a stiff application brush and a normal pressured garden hose. For specific cleaning situations like oil stains or spills, use commercial cleaners generally available at masonry supply outlets. When using any type of cleaner, always test on a small hidden portion of the pavement. Prewet pavement thoroughly before cleaning and rinse after with clean water. In mortared applications, use Sure Klean 600 or 202 New Masonry Detergent, or equivalent as directed. Vanatrol or 202V Vana-Stop or an equivalent product should be used to clean all light colored and brown pavers. DO NOT USE MURIATIC ACID. Pressure washers can be used provided application pressure is limited to 30-50 psi and a 50-degree Fan Tip is used. Rinse pressure should not exceed 200-300 psi.


Paver color is permanent. Sealers are not necessary for long-term durability or color retention. A large sealer manufacturer has done a disservice to clay pavers by suggesting that clay pavers will last longer if sealed with their silicone sealer. In fact, silicone sealers do not "breathe" and may contribute to spalling.
If a sealer is used, it should be a breathable sealer like siloxane. There are certain applications where sealers may be applied. For example, the largest theme park operator in the US uses a sealer to prevent sand loss during daily cleaning operations and to cut down stains left by chocolate ice cream and other food products. In vehicular applications, joint sand stabilizers are used to prevent sand loss (preserving interlock) that is common from street cleaning and tire suction (Surebond 1370 or Sandlock).

Moss & Weeds

The existence of moss is an indication of poor drainage(in a shaded area) as the saturation of water creates an ideal environment for growth. The best solution is to keep the area dry by improving drainage or elevation although these remedies may not be practical. For moss and organic growth removal, a three-to-one solution of water and chlorine bleach is recommended or a one to one dilution in severe cases. Weed growth in flexible base paving systems is common in lower traffic areas. Contrary to popular belief, growth takes place in the sand joint and not from underneath the pavers. Weed killer such as Round Up will handle existing growth while a pre-emergent weed killer can be used in the spring as a prevention measure. Joint sand stabilizers are also effective at weed prevention (Surebond1370 or Sandlock).

Snow Removal & De-Icing

Snow and ice can be removed with normal hand equipment or motorized vehicles. Snow plow blades should be equipped with a rubber edge and set at 1/4" above the pavement. Rotary brushes and snow blowers can also be used. The use of rock salts are not recommended for snow and ice removal because of the possibility of efflorescence. Non-sodium de-icers that are environmentally compatible are available as well as sand or cinders for traction control. An effective non-sodium deicer tested by PHB for effloresence, is IceBan. For information contact www.iceban.com.


Efflorescence is a crystalline salt deposit on the surface and in the pores of concrete, masonry, and other building products. A phenomenon reported as early as the 1870's and much studied since, it can appear as sulphate and carbonate compounds of sodium, potassium, calcium, magnesium and aluminum.
Chlorides may also occur as efflorescence. There are several sources for efflorescence:
1) the movement of groundwater that moves upwards, by capillary action or "wicking",
    into masonry or concrete materials.
2) salts in the soil that are in contact with paving can migrate above grade.
3) natural-state salts that are found in mortar, concrete or other building products.
4) contamination of masonry components (including sand) by seawater.
5) the improper use of hydrochloric acids in cleaning solutions.
6) the use of calcium chloride as a mortar accelerator.
7) the use of lime base aggregates as a base material or as bedding sand in the form of screenings.
8) salts used for de-icing purposes in the winter months, the most common outside source of efflorescence
     in paving applications.

Although rare, some raw material used to make clay brick contain small amounts of salt. However, these small amounts are minor compared to studies that found two to seven times as much soluble material in concrete products versus fired clay material. W.E. Brownell concluded in his research study that the most common form of efflorescence comes from the "migration of 'free-alkali' solutions from cementatious products. This would include any newly poured concrete curb, foundation or sub base slab.
Efflorescing salts dissolve in water and are absorbed into the masonry pores. Typically, clay bricks can absorb 5% to 8% of their weight in water. Heat from the sun (or other source) begins to draw the moisture to the surface and as the water completely evaporates, the salt deposits are left on the surface. Since humidity and moisture play a key role in the efflorescence process, some areas of the country will be affected more than others.
Seasons will play a role as precipitation during season changes will increase the likelihood of efflorescence.
The most important solution to solving efflorescence is the avoidance of efflorescing materials in the paving system. The second best solution is finding, locating and dealing with the source of water. Since the source of water in a paving application is generally clear, the most important factor in limiting the occurrence of efflorescence is insuring adequate drainage of the pavement through grading or specific drainage systems. Good drainage will keep the pavers dryer and thus, they will be less likely to effloresce. While efflorescence control systems are available, they don't guarantee full arrest of the problem and tend to be expensive.
The best thing to do is to allow the efflorescence to run its course provided that the paved area has good drainage. The main reasons for this recommendation are as follows: the source of the salt is most likely coming from base materials, mortar or de-icing salt residue. In a flexible base application, after 6 months,
90 % of the water will run off the paving surface and away from the pavers versus down through the joints. This change should help carry the salts in solution away from the pavement. In all cases, free salts dissipate eventually and the problem goes away for good, generally within 18 months.
As a general rule, the removal of efflorescing salts from the face of masonry is a relatively easy operation. Efflorescing salts can be removed with dry brushing or with clear water and a stiff brush. The crystals are superficial and do no affect the durability of the pavers.


Cleaning of Clay Paved Surfaces
These notes are intended for general guidance and are not intended to be exhaustive. Clay paving provides a durable, hardwearing surface but, like any surfacing material, this may suffer from time to time from staining, due to general trafficking and contamination from other sources.
Due to the nature of construction, there may also be some vegetation growing in the joints, or on the paving themselves in shaded areas or areas subject to long periods of dampness. As for any other surfacing material regular maintenance and good cleaning practice will enhance the overall appearance of the paving.

Initial maintenance - flexibly laid clay pavers
During the very early life of the pavement, the joints between the pavers will be relatively porous.
The ingress of water will consolidate the jointing sand and it is important that the joints are regularly filled with jointing sand to replace the sand consolidated by the rainwater. The joints will soon become semi-impervious due to detritus tending to seal the joints. Until this has occurred the paving should only be brushed by hand.

Mechanical sweepers, and in particular sweepers with high suction forces should not be used.
If they are used, there is a real risk of loss of jointing sand from between the pavers.

There is a number of water miscible liquids that can help to stabilise the joint filling sand. These can aid in the reduction of the removal of sand by suction cleaners, and at the same time, helps to prevent the ingress of water during the early life of the pavement. It is essential to consult with the paver manufacturer before applying any form of surface treatment.

General dirt and detritus
To remove general dirt and detritus, regular brushing is recommended. If detritus masks the colour of the material then this can be reestablished by scrubbing with hot soapy water. This can be carried out by hand or by using an industrial cleaner. Ensure that all the detergent has been thoroughly washed from the surface on completion of the cleaning and the resulting run-off is carefully channelled to either drainage points or containers where it can be safely disposed of. If a hose is used, then care must be taken to avoid the removal of the jointing material (sand or mortar).

Moss, lichens and algae
Moss, lichens and algae should not grow on clay pavers unless the area is heavily shaded, is under trees, or is not laid to an adequate fall. If such growth does occur and is considered undesirable then the area should be treated with a proprietary moss killer used in accordance with the manufacturer’s instructions.
Such products take some days to be effective and work best when applied during a spell of dry weather.
Any thick growths should be scraped off first and the chemical treatment well brushed in.
Some treatments leave a residue to discourage the re-growth of the moss and algae, but this will only be of limited value if the paving remains damp and in shade.

Rust stains
First of all, action must be taken to eliminate the sources of staining. To remove the rust stain the surface should be made wet and then the affected area treated with a 5-10% hydrochloric acid solution. Before cleaning, provision should be made for the collection and disposal of waste chemical materials, in accordance with legislative requirements. Buff clay pavers should NOT be treated with acid without first discussing the stain with the paver manufacturers.

Oil stains
Oil does not penetrate readily into clay pavers, but if oil is spilt on the pavers, the spillage should be removed promptly with an absorbent material, such as paper towels. The oil should not be wiped up; otherwise this will spread the contamination on the surface of the paver. Steam cleaning can be used on clay pavers to remove such staining, but if this is unsuccessful an emulsifying de-greaser should be employed. Brush with plenty of water to safe disposal. An alternative cleaning method is to brush the area with a strong detergent and hot water. This will not affect the colour of the clay paving.

Bitumen stains
Bitumen does not penetrate readily into clay paving. The best method of removal is to leave the bitumen until it has cooled. A paint scraper or a similar mechanical device can then often remove it. If it is particularly resistant, the use of ice to make the bitumen even more brittle may be required, prior to scraping it from the paving. Any residue should be removed with a scouring powder and finally the whole area rinsed with clean water. Certain proprietary cleaning agents are available to remove bitumen, but these should be tested on an inconspicuous area of paving first.

Graffiti and paint stains
Both paint and graffiti are difficult to remove. Fresh wet paint should be soaked up with an absorbent material without wiping the paint, as this will spread the stain. It should then be treated with a suitable solvent, such as white spirit, and then the area washed with a de-greasing agent taking care in the disposal of the run-off material. With dried paint, the paint should be scraped off as far as possible and then a paint remover to BS3761 (4) should be applied.

Smoke, fire and tobacco stains
Normally these stains can be removed by scrubbing with hot soapy water. Where the stains persist, scouring powder or household bleach solution has been found to be successful.

Beverage stains
These can normally be removed by scrubbing the stain with hot soapy water. If the stain is persistent, apply bleach solution and then rinse the area with clean water, taking care to dispose of the run-off safely.

Chewing gum
Chewing gum is one of the most difficult substances to remove from any surface material. Newly discarded gum can be scraped off by using a scraper, but hardened gum can only be removed by freezing the gum and chiselling it from the surface of the paving or, alternatively, by using a hot water/steam cleaner. There is a number of contract cleaning companies who specialise in this type of cleaning, and it is advised that they are contacted directly for further details.

Scuff marks from vehicle tyres
These can normally be removed by steam cleaning, or by scrubbing the area with hot water and a strong household detergent solution.

Efflorescence on clay pavers
Any soluble salts showing on the surface of the paver should be allowed to weather away naturally, as experience shows that such weathering will occur quite rapidly. These salts are not damaging to clay paving. Chemical treatments should not be used. Certain light coloured pavers are manufactured from fireclay and in extreme cases may suffer from metallic salts staining. Vanadium efflorescence takes the form of a yellow/green stain, and orange/brown deposits may result from iron or manganese compounds. These stains should be allowed to weather away naturally, but if they persist contact the paver manufacturer.

Cement staining
Remove large deposits with wooden implements to avoid damaging the paver surface. Following the pre-wetting of the area, treat the residue of mortar by careful application of a dilute hydrochloric acid solution or a proprietary cleaning solution. The application of the acid breaks down the cementitious components but is not damaging to clay pavers. As with all cleaning procedures a rinsing operation should be carried out shortly after application, and care taken to dispose of run off solutions safely. If the above method is not successful with coloured mortars, specialist advice from the coloured mortar supplier should be sought.
On the rare occasions when a vanadium efflorescence is present, hydrochloric acid based cleaners must not come into contact with the efflorescence, otherwise a dark stain will result which will become fixed on the surface.

Lime staining
Lime staining should not occur on flexibly laid clay pavers. However, contamination from an external source, such as concrete street furniture or concrete units, which are discharging run-off water onto the clay pavers, is a possibility. Lime staining eventually becomes insoluble and appears as a white stain. In the unlikely event that such staining occurs, the clay pavers should be wetted and the surface then treated with a hydrochloric acid solution of 5-10% concentration. As with all cleaning procedures a rinsing operation should be carried out shortly after application, and care taken to dispose of run off solutions safely.

Iron staining
This can appear in several forms from orange through to dark brown in colour and can affect the paver surface and lead to staining of any mortar joint. Iron staining will recede over time and is best left to weather away naturally. In severe cases however, the following techniques have found to be successful in removal of the stain.
Removal from the face of the mortar joint is best achieved by scraping or rubbing with a round file or carborundum slip. Where overall cleaning is required the following chemical treatment has been found to be effective: Brush on 5-10% hydrochloric acid solution. This is frequently satisfactory on fresh stains. To this end, proprietary brick or patio cleaners may be effective, but, as with all treatments, a small trial area should be carried out first. For more persistent stains, repeated application may be necessary.

Manganese staining
This is similar to iron staining but is generally dark brown or black in colour, and the treatment is essentially similar. If chemical treatment is required the following methods have been used: On fresh stains, brush on 5-10% hydrochloric acid solution or a proprietary brick or paver cleaner. In more severe cases a combined solution of hydrochloric acid (10%) and hydrogen peroxide (10%) can be effective or, alternatively, paint the stain with oxalic acid solution (120g/litre).

Mechanical Cleaning
The following recommendations deal with vehicles and associated equipment and their use:

1)  Equipment should be purpose designed to sweep the particular area.
     If there is any doubt, the vehicle manufacturer should be consulted.
2) Tyres should be inflated according to the manufacturer’s recommendations
     to ensure maximum weight distribution.
3)  Polypropylene, not wire, brushes should be used.
4)  Sweeping brush pressures should be set to the minimum required to suit the particular task,
     i.e. surfaces swept regularly will require a lesser setting than those swept infrequently or those
     covered with heavy deposits.
5)  When sweeping, engine revolutions should be set at the minimum required to maintain
     vacuum (suction) pressure.
6)  Operators, including reliefs, should be trained to vehicle manufacturer’s recommendations and tyre
     and brush pressures should be regularly checked.
7)  Advice should be given to operators that, when equipment is stationary or left unattended, suction,
     brush rotation and water jetting equipment should be switched off to avoid the risk of damage to the
     area below the stationary equipment.
8)  In new or re-laid areas, agreement should be reached with the local Highways Authority to allow
     the pavement to settle and the joints to seal before manual cleaning.
9)  When water jetting equipment to wash such areas is used, the jets or hand held lance should be
     directed at the surface at an angle not greater than 30o and across the diagonal (i.e. not parallel to joints)      using a suitable detergent solution.
10) The area should be inspected after cleaning to ensure that joints are refilled with jointing sand
     if necessary.