D. Adhesive Coatings (For adhering thin brick units to vertical return form rails)
IBS’ Pressure Sensitive Adhesive (PSA) is a water base adhesive that softens with water and can be removed with high pressure hot water. It is designed to aid in placing brick in the vertical areas of forms and will adhere to the VersaLiner and brick. It is an air dry material that acts like a contact adhesive. PSA can be applied in one of the following two manners: (1) Apply adhesive to brick and liner pocket (use a brush; or a cardboard edge will work as well). Once applied to the brick, allow adhesive to dry until tacky (approx. 5 – 30 minutes, depending on air temperature; the cooler, the longer) and then place into the VersaLiner pocket. Concrete can be placed within one hour after applying the adhered corner bricks. (2) Apply adhesive to brick and liner pocket and immediately bond the two. Let dry for 18 – 20 hours. Care should be taken during this time to ensure that the brick is undisturbed until the adhesive is cured enough to hold it adequately. This method will provide a more complete bond. The PSA is ideal for vertical wall casting applications where there is adequate cycle time for the forms to be prepared. In vertical form applications form is first laid horizontally. Next the VersaLiner is attached to the form face with staples and the coated brick is then placed into it. Once cured, the form is raised into vertical position and the concrete is cast. Removal of the adhesive is relatively simple if it is attempted soon after the concrete is cured and immediately after the VersaLiners are removed. The Adhesive continues to strengthen as it dries, making it more difficult to remove over time. Cleaning rates of about 50 square feet per hour can be expected if the panel is being cleaned within 30 hours of casting. Yields decrease the more time elapses. A worse case of 25 square feet per hour may occur if the adhesive is left for a prolonged time to cure.
E. Corner brick
Corner brick Corner brick are available for the thin brick system. These bricks are produced separately from the flat brick and have been known to vary in shade from the flat brick of the same color range. These differences are usually too minor to be concerned with however notice must be taken to insure the appropriateness of each batch of corner brick as it is being installed.
. Corner brick units may vary slightly from true 90 degrees due to unavoidable shrinkage and distortion during the manufacturing process. Each unit is factory checked for tolerances of plus or minus 2 degrees. While this is not a great amount of distortion, care should be exercised in installing these units so as to minimize the visual impact. Corners can be shimmed as they are placed into the forms if needed to balance the effects of angled units that are less than 90 degrees. Epoxied corner units are available from some manufacturers. Any thin brick can be epoxy adhered into a corner unit with relative ease. The major advantage is that a color match is assured. Onsite epoxying may prove to be less expensive to the installer as well. The flat brick are simply mite- cut and adhered together with a clear or paint-able adhesive that is mixed with the cutting dust from that brick. The resulting seam is hardly noticeable, especially beyond a few feet. Quirk and mitered joints are good choices whenever possible. They save valuable installation time and cost considerably less. (See IV.B.4: Module Openings, Corners and Quirk Joints)
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