Recommendations for the use of clay pavers
1. The base course as the underlay for the bedding materials must be sound, frost resistant and permeable. The base course must be installed in layers and compressed and have the slope of at least 2.5% necessary for the clay paver surface from the beginning.
2. The surround e.g. an offset rolled layer in mortar with a backrest on the outside will prevent the clay pavers from shifting at the edge. To ensure that the surface water will be able to flow away freely the upper edge of the surround should be placed about 1 cm under the finished height of the clay paver surface after compacting.
3. Construction materials consisting of broken aggregate with sufficient stability such as sand /chippings mixtures from hard stone such as basalt, diabase and such like are suitable. We advise against the use of limestone with unstable grains as a bedding material. For areas which will be exposed to little traffic and in private areas natural sand/gravel mixtures with a grain size of 0/4 and 0/5 mm are suitable. Bedding material with soluble substances should not be used. Be careful with recycled material.
Further details on bedding materials may be found in the Data Sheets.
4. When compacted the paver bed should measure no less than 3 cm and no more than 5 cm.
5. The joints for clay pavers should measure at least 3 mm. The joint width should be planned not to exceed 5 mm. When clay pavers are laid together narrowly the edges may split. The joint line should be even and preferably measured with a string when being laid. The joint serves to equalize unavoidable material tolerances.
6. The grouting should match the bedding material in grain size. Broken aggregate with a grain size of 0/4 and 0/5 mm is suitable for roadways as well as in a 0/2 mm grain size which is swept in to close the joints and followed up with a limited amount of water.
Further details on joints and grouting materials may be found in the Data Sheets.
7. Clay pavers are to be laid on a prepared, compacted and smooth surface. Several packs of clay pavers should be opened and used alternatively. To prevent the clay pavers shifting the joints should be steadily filled with grouting as laying proceeds.
8. The compacting should be done with a vibrating machine equipped with a plastic protective sheet.
9. After compacting the joints should be closed with a further wet sifting. The clay paver surface should rest for some days before use to stabilize the joints and grouting materials. In the first few months of use a mechanical sweeper with a suction tube should on no account be used.
10. In spite of all precautionary measures taken a light grey bloom may form on the clay paver surface. This disappears through weathering.
11. In areas under large roofs or under car ports, which are not affected by weathering, any sediment or bloom should be swept or washed away.
12. In the case of stubborn sediments remaining it may be necessary to use semi-mechanical brushes or commercially available stone cleaners.
13. Power cleaners should not be used because the grouting might be washed out of the joints. Cleaning machines using water and rotating brushes are preferable.
14. Clay paver surfaces should be cleaned gently. If machines are used then without suction. Road sweepers should not be used in the first year after the pavement has been laid.
Tips for Care
Adding sand: joints should be checked regularly and re-filled with grouting if necessary. The clay paver surface will only remain stable if the joints are closed and compacted. The use of road sweepers with suction should not empty the paver joints.
Roofed-in areas: In areas with overhanging roofs and under car ports a white bloom may appear from the layer under the surface. Since the normal cleaning effect through rain cannot happen this should be imitated using commercial cleaners and brushes.
Green sediment: In shady and damp areas a green film may appear on the clay paver surface. If this is slippy or unappealing it can be removed using mechanical brushes or commercial cleaner. Power cleaners should only be used with the greatest care as if incorrectly used they will empty the joints.
Grey bloom: Salt sediments which often appear in spring as a grey/white bloom on the surface can be swept away or disappear by themselves after rain. Using sand, gravel or granulate is preferable to salt.
Recommendations for use
The clay pavers should be cut using a cutter which uses water. A disc grinder used without water should never be used because of the possible health risks when breathing in the dust.
Clay pavers should only be laid by people wearing protective clothing e.g. gloves, steel-capped shoes etc.
When using commercial cleaners the manufacturers’ instructions should be followed carefully. The substance should be tested for suitability on an unimportant section.