Masonry Magazine April 1993 Page. 33
Efflorescence
Many times efflorescence, a white powdery substance produced by soluble salts, is unavoidable on a paving surface. Deicers used on adjacent areas may be deposited onto the brick pavement, soluble salts may be present within paving system components or salts may migrate from adjacent soils. Therefore, proper drainage and maintenance are especially critical to reduce the amount of efflorescence. If efflorescence does appear on the paving surface, natural weathering or traffic will usually eliminate it. See *Technical Notes 23 Series* for more information of efflorescence.
Coatings
Coatings or sealers are often desirable on interior brick floors to facilitate cleaning. Coatings on exterior brick pavements are not recommended unless the coating has been proven to perform on exterior brick pavements. Coatings generally have two purposes, to lock loose sand in the joints for mortarless paving and to prevent staining and facilitate cleaning. Coatings used to prevent jointing sand erosion should be applied to the joints only. All coatings used in exterior applications must have a high vapor transmission rate and not adversely affect the slip resistance of the pavement. Before any coating is applied, the pavement surface should be fully dry and clean. The choice of any coating should be based on its intended result.
Repairs
Repointing of mortar joints may be necessary due to deterioration of the mortar. Procedures given in *Technical Notes 7F* should be followed. A stronger repointing mix is recommended for paving applications than for wall applications. Type S mortar is usually sufficient to provide good durability as a repointing mortar.
At some time, a brick pavement or utilities under the pavement may have to be repaired. In mortared brick paving, units and base materials that are removed should be discarded and not used again. The returned fill and subbase should be well compacted and the new base poured in place. The mortar and pavers should be replaced using techniques similar to those described for new construction.
In making repairs on flexible brick pavements, the paving brick may be reused. A single unit is removed initially, preferably with a purpose-made tool to prevent damage of the paver. Adjacent pavers may subsequently be removed and stacked nearby to be used again if not damaged. Temporary edge restraints should be placed at the perimeter of the exposed area to minimize creeping of the pavement. At all times, vehicular traffic should be kept at least 6 ft (2 m) away from the work edges. Proper compaction of the new or returned fill material is very important. Fill material should be brought up to the proper level and compacted. If the area is too small to permit proper compaction, self-stabilized materials such as concrete should be used. One to two ft (0.3 to 0.6 m) of pavers around the perimeter of the excavated area should be removed so that accurate levels can be established from undisturbed work. The sand setting bed should be screeded and compacted. A thin layer of sand should be screeded on top of the setting bed to bring the setting bed to the proper level. The pavers are then re-laid in the correct bond pattern. If creep of the pavement has occurred during repairs, some units may have to be saw cut to fit, although temporary edge restraints should avoid excessive creep. Jointing sand should be spread over the top of the pavers and the system vibrated to the finished level with a plate compactor if appropriate.
SUMMARY
This *Technical Notes* describes the proper selection of materials and installation methods for brick paving assemblies. The importance of proper installation cannot be stressed enough for pavement performance and longevity. Information on maintenance of brick paving assemblies is also provided.
The information and suggestions contained in this *Technical Notes* are based on the available data and the experience of the engineering staff of the Brick Institute of America. The information contained herein must be used in conjunction with good technical judgment and a basic understanding of the properties of brick masonry. Final decisions on the use of the information contained in this *Technical Notes* are not within the purview of the Brick Institute of America and must rest with the project architect, engineer and owner.
REFERENCES
1. *American National Standard Specifications for the Installation of Ceramic Tile*, Tile Council of America, Princeton, NJ, 1985, 57 pp.
2. *Flexible Brick Pavements: Design and Installation Guide*, Brick Institute of America, Reston, VA, 1991, 26 pp.
3. Harris, C.W. and Dines, N.T., *Time-Saver Standards for Landscape Architecture*, McGraw-Hill Book Co., New York, NY, 1988.
4. Kulakowski, B.T., *Evaluation of the Frictional Characteristics of Brick Pavers*, Final Report submitted to the Brick Institute of America, Pennsylvania Transportation Institute, University Park, PA, November 1991, 57 pp.