High-pressure cleaning
In some cases, periodic pressure cleaning of paving stones may be required at prominent entrance locations. Typically, a high-pressure sprayer with sufficient force to loosen dirt and clean the paving units will work quite well. (Note: When using pressure sprayers, the water should be applied at a 30-degree angle to avoid loss of joint sand.) For smaller areas, adequate cleaning can often be achieved without high-pressure cleaning equipment. For residential patios, walks, or small driveways, cleaners can be applied with brushes to remove dirt. After scrubbing the pavers, the surface should be cleaned and rinsed thoroughly with water.
When cleaning pavers around pools, high-pressure spraying is not normally recommended. To avoid water chemistry issues professional landscapers typically use the water stream from a garden hose, carefully applied at an angle, to avoid water, sand, or debris from entering the pool or other bathing vessel.
Then, pavers are cleaned by hand using a solution of household bleach and water (mixed using a proportion of one part bleach to four parts water), or a mixture of two quarts of white vinegar mixed in 3.78 L (1 gal) of water. Using a reasonably stiff scrub brush, it should be possible to clean two to three pavers at a time until the job is complete. After this is accomplished, rinse the pavers with the garden hose, remembering to propel the stream of water away from the pool or bathing vessel.
Minor repairs for paving stones
The combined effects of frequent freeze-thaw cycles, moisture, and vehicular traffic over time can result in a noticeable settlement of pavers, particularly near curbs, site fixtures, and walls. Settlement can also occur as a result of loss of bedding sand or base materials usually as a result of rainfall and near downspouts where water flows directly onto the pavers during rainstorms. Fortunately, this is not a permanent problem and can be rectified.
To avoid pool structure problems caused by heavy compaction equipment, a hand tamper or rubber mallet is typically recommended. For new pool and bathing vessel installations many contractors have successfully installed 610 mm2 (24 in.2) landscape stones at the perimeter, leaving approximately 51 mm (2 in.) for installation of the required bedding sand. This fine bedding sand can be adequately compacted by hand thus avoiding mechanized compaction.
To repair base materials under the paving units that have shifted (and those in close proximity), the pavers should be removed and set aside to be re-installed later. If the settlement is minor (i.e. fewer than 10 mm [0.4 in.]), additional bedding sand can be added with the pavers placed at a slightly higher elevation than existing units and then compacted so that they are level with surrounding pavement surfaces. If settlement is greater than 10 mm, then the bedding sand should be removed and the depression filled with base material and compacted.
The next step is to replace the bedding sand and pavers as previously described. (When there are many cut pavers to re-install, it is a good idea to number the pavers with chalk prior to removal to allow for proper re-installation.)
When re-installing pavers, the joint between units should be kept tight (2 to 4 mm [0.7 to 0.15 in.). After installing and compacting the pavers, the joints should be filled with sand and the area further compacted.
