Ceramic glazed products have been an integral part of building designs for many decades.

Historically, they have performed well under all climatic conditions. Successful performance of glazed brick exterior walls can be expected through the use of conventional drainage wall types that allow water drainage and air venting. Attention must be given to proper material selection, detailing and construction practices to ensure a successful design. Click the links below for details.

Mortar should be limited to those mixes conforming to ASTM C270. Admixtures and additives for workability are not typically recommended. Type N mortar should be used in veneer construction, except in areas of expected high wind loads, i.e., over 25psf (1.2 kPa). In these areas, Type S mortars should be used in loadbearing construction. See Brick Industry Association Technical Notes 8 series.

Typically Type N, or if a Type S is being used for the masonry backup wall being constructed at the same time, then it is OK to use that mortar on the SGT/Glazed Brick. Masonry Standards Joint Committee1 (MSJC) requires that the shear strength developed between the adhered veneer units and the backing be a minimum of 50psi.

When conditions call for specific mortar surface characteristics such as chemical, scratch or graffiti resistance, the addition of joint filler or a mortar additive may be needed. There are several products and methods to address these needs depending on the environment. Contact the individual manufacturer of the additives to determine the proper product for your specific application. Follow the manufacturer’s directions carefully in the preparation and application. In general, the most common application is to rake back the newly installed, thumbprint hard mortar joint 1/4” to 3/8”, clean away crumbs. Then add the joint filler using a bag or caulking gun or else apply using the tile setters’ method. Clean the excess filler from the masonry unit face immediately or within the time allowed per the guidelines. Finishing joints as flush or slightly concave will yield the best results.

Ties for veneer applications over steel stud back-up systems should be of a two-piece, adjustable variety. They should be hot-dipped galvanized for protection against corrosion and spaced per every 1.67 sq.ft. of wall area. See Brick Industry Association Technical Notes 28B Revised. Ties for these cavity wall applications may be adjustable or unit ties. Corrosion protection should be a minimum of mill galvanizing. Tie spacing should not exceed 3 sq. ft. of wall area. See Brick Industry Association Technical Notes 21 series.

Install type of wall ties as recommended by wall tie manufacturer or as directed by your local building codes. Space wall ties in the mortar joint, typically every 16” o.c. vertically and every 32” o.c. horizontally.

Flashing material should be sufficiently tough and flexible so as to resist puncture and cracking. In addition, it should not be subject to ultra-violet deterioration or other deterioration when in contact with metal, mortar, or with elastic sealants. Flashing materials are generally formed from sheet metals, bituminous-coated membranes, rubber, or combinations thereof. The selection is largely determined by cost and suitability. Acceptable bituminous membranes do not include asphalt-impregnated felt. The cost of flashing materials varies widely. It is suggested, however, that only superior materials be selected, since replacement in the event of failure is extremely expensive. See BIA Technical Notes 7A Revised.

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 cotton 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 for 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.

The nominal 2” Structural Glazed Tile (SGT) or Glazed Brick masonry units are to be mortared directly to a backup wall. Following are the recommendations of the Ceramic Glazed Masonry Institute.

Nominal 2” clay masonry units with integral ceramic face(s).

The addition of horizontal joint reinforcement in the bed joints is required in stack bond masonry. Reinforcement in the bed joint provides additional in-plane arching action between the masonry units. This joint reinforcing is typically 9 gauge (W1.7) wire spaced at a maximum of 18” o.c. vertically.

Tool or strike mortar joints on exposed face when they are “thumb print” hard. Tool all Glazed Brick joints concave using a non-metallic tool 1″ in diameter or larger unless otherwise noted.

According to the Brick Industry Association and MSJC, the Empirical Design Requirements for anchoring a 2” veneer to a concrete or masonry substrate has no specific height limit regardless of the seismic zone. MSJC limits adhered veneers weight to be a maximum of 15 lbs/sf.

It is not necessary to have expansion joints on an interior SGT/Glazed Brick wall; however, control joints are necessary in a CMU wall. This requires that there be isolation through the SGT/Glazed Brick veneer. A compressible material of the same size as the CMU control joint should be used in this veneer movement joint.

Butter the edges of the SGT/Glazed Brick with mortar. Allow enough space (max. ½”) for the mason’s fingers to place the units. Allow the mortar in the head and bed joints to squeeze out of the back of the units, therefore bonding to the surface of the masonry backup. Engage wall ties in the bed joints of the masonry backup and into the bed joint of the 2” SGT/Glazed Brick unit.

When adding an SGT/Glazed Brick veneer to existing concrete or masonry walls, its weight may be supported directly on either existing or new concrete foundations. Alternatively, where existing concrete or masonry foundation walls provide sufficient strength, the veneer may be supported by steel angles anchored to the existing foundation walls. The BIA has always put a height limit on veneer supported by an angle. CGMI recommends a height limit of 14’.

As always, all state and local building codes would apply and a structural engineer’s review and approval is recommended. It is not possible to address every possible condition from this document. Anyone using this data sheet is ultimately responsible for the application and use of this information.

  1. Masonry Codes and Specifications Compilation; www.masonrysociety.org
  2. Brick Industry Association, Technical Notes 18 and 28 Series; www.bia.org
  3. CGMI, Ceramic Glazed Masonry Institute