Frequently Asked Questions
Ceramic Glazed Brick
What Is a Ceramic Glazed Brick [CGB] and how do I spec it?
It is a brick made of clay, shale, fireclay or a mixture thereof. It has a ceramic glazed finish that is fired on at very high temperatures. When installed properly the units will provide a durable and easily cleaned wall for the life of the building. Prior to 1998 an architect had to combine two ASTM specifications (ASTM C-126 and ASTM C-216) in order to properly specify a ceramic glazed brick. In 1998 a new standard was issued under ASTM C- 1405 Standard Specification for Glazed Brick for Solid Brick units. This specification permits an architect to specify the Grade (‘S’ or ‘SS’), the Type I (for single face), Type II (double face) and the Class (Exterior or Interior). All ceramic glazed brick must meet the strength and specific absorption requirements of this specification. The tolerances on dimensions are clearly indicated in the specification.
What do I need to know about Ceramic Glazed Brick?
Ceramic glazed brick are available in many sizes, shapes, and colors. These items vary depending upon each manufacturer’s capabilities. The ceramic glazed brick sizes range from a modular brick, 2-1/4″ x 7-5/8″, up to a 7-5/8″ x 15 -5/8″ face size. Keep in mind that ceramic glazed brick stretchers come with only one face glazed and the architectural drawings should provide sufficient clarity for the mason to understand where comers and special shapes should be used. Availability of the ceramic glazed brick is generally 6 to 10 weeks for new material depending on the size / complexity of the order. Frequently, what is needed for smaller projects can be pulled from material the plant has on hand left over from previously fabricated orders the key is always to plan ahead and talk to us about your order early.
What should I consider regarding wall construction?
Water penetration is a primary concern when installing ceramic glazed brick. Proper design, detailing and construction is more critical with ceramic glazed units than regular face brick. The impervious glazed face does not permit moisture to penetrate its surface. It conversely does not allow moisture to get out. Once moisture has penetrated the wall, which it will, through the mortar joints, sills, coping, normal condensation, we must provide a way to expel the water. As with any type of masonry construction, excessive water buildup can cause problems, especially if subject to freeze-thaw conditions. To help eliminate water buildup from any brick wall, and particularly ceramic glazed brick walls, begin by laying the field brick with the coring/cells laid vertically. This allows gravity to work for you by draining the water down through the wall. The walls should be designed with a 2-inch cavity between the interior and exterior wythes. The design should include proper flashing with weep holes and vents. Flashing is necessary at the base course, sills, coping, at shelf angles and below all wall openings. When installing the flashing it should be extended beyond the edge of the wall. Weep holes, open head joints or vents should be laced 24″ on center in the first course of brick and above lintels and spandrel beam supports. Place vents in the top of the wall and at shelf angles. This allows for air circulation within the cavity to promote moisture evaporation. Be sure to keep the cavity clean and the weep holes/vents open and mortar-free. For ceramic glazed brick walls that are enclosing areas where the inner wythe will be heated, a vapor barrier should be placed on the inner wythe or warm side of the cavity. Coating this inner wall with a water emulsion type of asphalt coating will reduce condensation within the cavity.
How do I use Expansion Joints, Wall Ties and Anchoring?
Ceramic glazed bricks made of clay generally undergo less expansion than other types of masonry units. A 3/4″ vertical expansion joint should be provided for every 25′ of joints in a face brick building. Soft joints should be placed under coping, sills and shelf angles. Wall ties connecting two wythe of masonry should be placed at least every 16″ vertically and every 32″ horizontally. Ladder or truss type reinforcement can b€ used where more strength is required. Flexible anchors should be used at beams and columns to allow for movement.
What type of Mortar is recommended?
Most Ceramic glazed brick jobs will use either Type N or Type S mortar, as specified. Mortar selection and preparation should be based on ASTM C-270, according to the strength requirements necessary. Ceramic glazed brick generally have a low rate of absorption and need less water when mixing the mortar giving it a stiffer consistency for ease of laying and less floating of the units in the wall. Lay the brick with full head and bed joints. Do not use any type of sealer on the mortar joints when installing exterior glazed brick. You must allow the joints to “breathe”.
What can I expect when cutting or drilling structural glazed tile and glazed thin brick?
Ceramic glazed bricks are usually dense and therefore harder and more brittle than concrete block and some brick. For this reason, it is best to use a continuous rim diamond blade on a wet cutting masonry saw. Using a dry-cut saw or other abrasive blades may result in excessive chip page to the edge of the cut. When drilling it is best to use a low-speed water-fed drill with a diamond core drill bit. Always keep water on the area while drilling and never allow the drill to become overheated.
What is the best way to clean glazed tile and glazed brick?
The glazed surface should be wiped clean after the joints are tooled or when the joints are thumbprint hard. Use a course rag such as burlap, corduroy or carpet. The longer the mortar remains on the surface the more difficult it will be to remove. Do not use metal scrapers or abrasive powders on the ceramic glazed unit. A wooden tool or paddle should be used to remove any mortar residue including lumps. Once the mortar joints have hardened the wall should be cleaned down with clean water and detergent using sponges or a clean cloth. For more difficult areas use a detergent masonry cleaner following the manufacturer’s directions carefully. Clean only small sections of one to two square yards at a time. It is very important to wet the wall before you begin and rinse immediately after with clean water. For more information visit our webpage (cleaning)
Additional information can be found at Ceramic Glazed Masonry Institute
Structural Glazed Facing Tile
What Is Structural Glazed Facing Tile [SGFT] and how do I spec it?
Structural Glazed Facing Tile is a durable building product appropriate for either loadbearing or non-loadbearing applications. Its impervious glazed surface resists fading, impact, fire, graffiti, and abrasion, making it a cost-effective solution for any project. SGFT can be used as structural walls, partition walls, multi-wythe walls or veneers. The ceramic finish is available in wide palette of colors or can be custom ordered.
The History of Glazed Brick and Structural Glazed Facing Tile Structural
Glazed Brick and Tile were first used in the United States in the early 20th century. Many of these first glazed units were manufactured as “salt glazed” brick and tile. This process was taken from the pottery industry. This glazing process utilized the use of regular table salt, NaCl, and reduced oxygen during the burning of the units. The salt was shoveled through small openings at the burner locations onto the gas fuel. The salt then vaporized and chemically mixed with the silicates of the body to form the salt glaze finish. This type of glazing has been discontinued for environmental reasons. Many salt glazed brick and tile buildings can still be seen today. You can recognize them by their wide color range-from a buff to an orange-brown color. The finish is transparent, showing the body color, which adds to the color variation. It also has small bumps in the glaze finish. Even though a true salt glaze is no longer available, Elgin-Butler Brick does offer many ceramic glazes in an attempt to match these old type glazes. Due to today’s tighter color control, you may need to use more than one color to achieve a wall with wide color variation. Today the quality control standards for the ceramic glazed finishes are much more stringent. ASTM C-126 outlines the minimum standards for imperviousness, glaze opacity, hardness and abrasion, fading and chemical resistance. Under ASTM C-126, units must also have ratings of 0 smoke density, 0 flame spread, and 0 fuel contribution and emit no toxic fumes.