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Wall System Moisture Detailing - Due to the imperviousness of the ceramic finish, glazed brick walls are recommended to be designed to drain all water that enters the wall system. This water may have its source in wind driven rain or condensation of water vapor. It is recommended, for glazed brick exterior walls, that a vented drainage type wall system be designed, detailed and constructed. This will accommodate the proper flow of collected water within the wall's cross section. Two common examples of drainage walls include the cavity and veneer designs utilizing a minimum 2-inch cavity between wythes. In either design, flashings and weepholes need be provided at the wall base, under sills, over lintels and relief angles, and under masonry or stone caps and copings. Flashings need to be continuous around the building perimeter at the wall base, relief angles, and copings. Isolated flashings, such as window sills and lintel angles, should be treated with end dams. Weepholes should be spaced at 24 inches on center, in head joints at the elevation of the flashings. Should a rope wick be used as the weephole material, an opening should be provided in the course above. This opening could be a vent or tube insert. These should be spaced at 24 inches on center. At the top of a wall expanse, vent inserts should be incorporated to allow air circulation in the drainage space. These vents should be located a course or two below the next flashing location and be spaced between 24 and 48 inches on center depending on the interior humidity in the structure. Movement Detailing - Brick masonry walls move with changes in temperature and moisture content. Wall detailing for the drainage type walls utilizing a glazed brick facing wythe needs to incorporate room for brick's growth. These joints, placed vertical and horizontal, break the wall into panels. The panel size should be limited to a length of 25 feet to ensure stress levels within the masonry strength. Panel heights will vary with the building and wall design; however, should be placed as soft-joints under relief angles. Additional joints, vertical and horizontal should be utilized in the building parapets to limit panel lengths to 15 feet and isolate the cap or coping from the facing wythe. The building geometry will also indicate locations for vertical expansion joints in glazed brick walls. These areas include; corners (one side), changes in wall height, and offsets in the wall plane. All joints should extend full height from foundation to top, or from shelf angle, and be free of non-compressive materials. Typical expansion joint size is one-half inch and is finished with a backer-rod and elastic joint sealant. Wall Design - The glazed brick facing wythe should be designed with the Masonry Standards Joint Committee provisions in Chapter 12 on veneers. This design procedure could be a rational approach analyzing the transfer of applied stress through the wall section, based on relative stiffness or, in areas with wind pressures under 25 psf, a prescriptive design approach can be used. In either case, the successful design is based on elimination of cracking of the facing wythe under applied loading. Glazed
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