Regular maintenance and good cleaning practice will enhance the overall appearance of your paving.

General Cleaning of Paving

Regular hosing and sweeping will not only keep your paving looking clean but it will also prevent weeds from taking root as they usually grow when seeds are left undisturbed to germinate in the debris that collects in between the pavers

To remove general dirt and detritus, regularly hose down your paving and sweep with a hard bristled outdoor broom.

When the paving is quite soiled, scrub the area with a hard bristled brush or broom, soap (a general purpose, pH neutral/slightly alkaline, non-abrasive cleaner can be used) and some elbow grease. Ensure all the soap has been thoroughly washed from the surface after cleaning and that the run off soapy water is channelled to drainage points or containers where it can be safely disposed of.

Note: Do not use power hoses to clean paving, this may wash out jointing sand and damage the grouting between pavers and will damage the pavers themselves.

Stain removal & Spot Treatments

Moss, lichens and algae: Moss, lichens and algae should not grow on concrete unless the area is heavily shaded, under trees or not adequately drained. If such growth does occur and is considered undesirable then the area should be treated with a cleaner suitable for the purpose, used in accordance with the manufacturer's instructions.

Rust stains: Action must be taken to eliminate the sources of staining. Remove the stain by using an acid based cleaner as described below.

Oil stains: As soon as the stain appears dab excess spillage with an absorbent cloth or towel. Then remove the stain with soap, water and a brush. Ensure that all residues are washed away with hot water.

Chewing gum: Chewing gum is one of the most difficult substances to remove from any surface. Newly discarded gum can be scraped off using a scraper. Hardened gum can be removed by chiselling it off the surface, using a hot water/steam cleaner or by chemical means. There are contract cleaning companies who specialize in this type of cleaning, and it is recommended that Homeowners contact these companies directly for further details.

Scuff marks from vehicle tyres: These marks can normally be removed by scrubbing the area with hot water and a strong detergent. Remember to rinse thoroughly.

Concrete, plaster and paint marks: Call in a paving professional to assist with the cleaning of these particular marks on your paving. While not recommended, consumers can use a diluted acid-based cleaning product, please see instructions below.

Smoke, fire and tobacco stains: Stains like this can normally be removed by scrubbing with hot soapy water. If the stain is persistent, apply mild bleach solution and then rinse the area with clean water, taking care to dispose of the run-off safely.

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

How to remove stains using an acid-based dilution:

Acids and acid-based cleaners can have an adverse effect on certain types of concrete paving. No acid-based cleaning materials should be used to clean pavers, as they could discolour or damage the paving surface as the acid reacts with the iron oxide and can alter the colouring quite dramatically. Acid-based cleaners should only be used on the stained area and not as a general cleaning solution.

Bosun Brick recommends that a professional be used to do any acid-based cleaning and does not recommend that this is done a DIY project, however, if this action is taken as a DIY project please follow the steps below:

1. Thoroughly hose down the pavers prior to applying the acid dilution; this will prevent them from absorbing the acid dilution as pavers will soak up the clean water first.
2. Apply the acid dilution according to the manufacturer’s instructions
3. After cleaning the area with the acid-based dilution, wash it off with water as quickly as possible in order to prevent damage to the pavers.

Weeds:

It is a common misconception that weeds grow though the paving. This does occur in rare cases; however weeds almost always grow from seeds and bird droppings that land in the jointing sand. Regular hosing and sweeping of the paved area will prevent weeds from growing as it disturbs newly emerging weeds and gets rid of them before they can fully establish themselves

Steps to remove weeds amongst your paving:

1. Treat your paving with a general-purpose organic weed killer two or three times a year.
2. A solution of the weed killer should be prepared according to manufacturers’ instructions
3. Apply the weed killer to the paving with a watering can, ensuring every part of the paving is doused with the solution

Note: Always look for organic products that have been specifically developed for use with paving or in gardens, rather than general herbicides, which kill everything. Weed killers that are suitable for paving or garden use tend to be slightly more selective and target the weeds without discolouring the paving or killing off adjacent lawns or bedding plants

Maintenance tips:

Inspect paving on a quarterly basis:

This is done to check for any loose, damaged or stained paving, and to ensure that the jointing material is intact.

• Should you discover loose paving, it is important to rectify the cause of the movement, settlement. Subsidence of the substrate layers are the most common reasons for pavement failure, which may be a result of numerous factors including:
  
  1. incomplete compaction of the substrate layers during construction
  2. unstable bedding layer due to water ingress
  3. failure of the restraining edges
  4. loss of jointing material
  5. application of loads greater than the pavement was designed to carry
  
  No matter what the cause, it needs to be investigated and rectified before replacing or re-bedding the paving units.

• Should you discover damaged or stained paving, the individual blocks can easily be replaced. Homeowners can refer to the Bosun Brick website for further information on how to relay damaged paving.
• If the jointing material is no longer intact: The pavers simply need to be topped with jointing sand by brushing or sweeping in dry jointing sand as required.

Note: Jointing material may be lost from paving joints in early life because the joints have not yet become stabilised (naturally or chemically). It is therefore important to inspect areas of new paving regularly in their early life and top up joints if necessary.

Maintaining your paving during construction: Remember when it comes to cleaning and maintenance, prevention is better than cure. Paving should be kept covered during construction or renovation to protect it from damage and possible staining from paint or oil-based substances as well as any harsh chemicals.

Sealing of block paving:

Any form of surface sealing used on the paving must be applied in strict accordance with the manufacturer's instructions.

It must be accepted that sealants may have an effect on the colour of the paving, its slip/skid resistance and may require on-going maintenance during the life of the paving. It is also important that the surface of the units is dry, clean and efflorescence-free before any sealer is applied.

Benefits of sealing your paving:

• Improving its appearance
• Under some circumstances, prolonging its life.
• Help seal the jointing material
• Inhibiting weed growth
• Stain prevention (especially from oil based stains)

If you choose to apply a sealant to your paving, call in a paving specialist to do the job.

Facts about Efflorescence:

• It is a natural phenomenon known as efflorescence that occurs in all concrete products
• Appears like a “whitish” film that become visible on the surface of the pavers.
• It consists mainly of the insoluble calcium carbonate (CaCO2)
• Should be seen as a passing nuisance. This white haze is often blamed on the manufacturer, unjustifiably so, as it is a natural phenomenon that occurs in ALL concrete products (this is because it is a natural by-product of all hardened concrete)
• It is caused by moisture reacting with lime and other minerals present in the cement and aggregates
• Can be exacerbated by the material on which the concrete pavers lie. Naturally occurring salts in the bedding sand or bedding mortar, will migrate to the surface of the paving and become apparent on the face of the paver
• Will disappear over time, in the most severe cases it can take up to 2 years
• Can be reduced (and in some instances eradicated) by using a dilution of Hydrochloric Acid, this sort of treatment may only be done by a professional paving contractor.

Note:

The information above is intended for general guidance on the cleaning and maintenance of precast concrete paving and is not intended to be complete.

It is particularly important with all cleaning methods that trials should be carried out on a small, preferably inconspicuous area, to determine the effect of the treatment before commencing work on a larger area.