Maintenance
Just like a pair of shoes or your car, paving also needs to cleaned and maintained regularly, to keep it looking great. Occasional sweeping and hosing is usually all that is required to ensure the paved area is kept clean.

If this is not enough to remove a stubborn stain, washing with a detergent or proprietary cleaner may be required. One of the advantages of clay products is that you can use chemicals to clean stubborn stains, but in some instances you have to be careful which chemical you choose. If you are going to use chemicals to remove a stain, it is important that you completely wet the paved area before applying any chemicals. It is strongly advised that you test for a reaction on a small and inconspicuous area of the paving prior to doing the whole area.
The use of hydrochloric acid is generally not recommended, except in extreme circumstances in a controlled environment.

Common stains and remedies are:

Efflorescence:
This is a powdery deposit of salts (usually yellow or white) found on the surface of pavers, often after rain. The source of this salt is more often than not, from the materials used in the job e.g. the base that the pavers are layed on, or the sand that is swept between the joints. Efflorescence is usually harmless and can be removed by dry brushing or hosing. However, it sometimes necessary to follow with a proprietary cleaner to remove the last of it.

Fungi/Mould/Moss:
These are common in shady or damp parts of the paved area. They can appear to be dark stains or patches of green. They will not damage the paved area, but may cause the pavers to become slippery. To remove these growths, simply clean with liquid chlorine or regular household bleach as they are fungicides. Allow for 4-5 days to act.

Timber stains:
Sometimes timber or leaves can leave a stain on pavers if left in contact with the paver for a long period of time. This stain is tannin, and can be easily removed with 3% solution of Oxalic Acid.

Tyre Marks/Food Stains:
Particularly when a pavement is new, it can become susceptible to tyre marks from vehicular use. This can be removed by simply scrubbing with full strength detergent.