When is it the right approach?
By Randy Wilson
Thin brick is an extremely diverse material. The material’s lightweight and slender profile give it the opportunity to perform where full-face brick cannot. Interior applications and renovations are obvious areas where thin brick does not require a foundation support and/or steel support angles. The question is: If thin brick is advantageous in areas where additional structure is not feasible, why should we add these support components at all?
The 21st century approach to holistic architecture must include economical and environmental impact studies. The client expects you to give them cutting-edge solutions to their space and habitation needs. When the owner desires a masonry appearance, we should not assume a full-face brick cavity wall is the only solution.
The better solution is to fully understand all of your wall system choices and determine the best fit for your client’s needs. Once the wall system is chosen, the brick material can be selected based on the most compatible installation method.
Thin Brick – The Material
Thin brick, once installed in the final wall, will give the identical appearance as a face brick assembly. The material is typically no less than half-an-inch thick and no greater than 1 inch thick. The material is comprised of shale and/or clay, and is kiln fired the same as a face brick (ASTM C216). Just like a full brick, a thin brick (ASTM C1088) can be provided with a variety of appearance characteristics.
The design construction professional should assess each material’s distinctive qualities and the wall system requirements before selecting the final brick size, color and texture. The Brick Industry Association Technical Notes (www.gobrick.com) will inform the designer of every brick type available in the marketplace – including thin brick (Technical Notes 28C).
Using the proper thin brick for your wall system application is critical. Thin brick is produced in one of the following methods:
- Extrude the brick face from the brick body before firing in the kiln.
- Cut the brick face from the brick body after the material has been fired in the kiln.
- Extrude the thin brick as a split tile.
The first two options (removing the face from the full brick) are the methods used by traditional full brick manufacturers to meet the market demands for thin brick. Thin brick cut from a full brick possess the same material characteristics as the full brick. Standard severe weather brick characteristics include water absorption of less than 17 percent (most often between 6 percent and 10 percent) and size tolerances of plus or minus 1⁄4 of an inch.
A thin brick produced as a split tile will perform as a quarry tile (water absorption between 2 percent and 6 percent and size tolerances of plus zero to minus 1⁄16 of an inch). The split tile machinery extrudes a smaller cross-section of raw material, thus requiring 70 percent to 80 percent less material, electricity and natural gas to produce the finished product. It is truly the environmental choice to achieve a brick appearance.
When the brick face is cut after firing, the thin brick production environmental savings are non-existent. The only savings are limited to trucking. From an economical perspective, cutting the face from a full brick adds a step to the manufacturing process. Therefore, these thin brick’s tend to be more expensive than thin brick produced via the split tile method.
The designer should become familiar with the thin brick pieces offered. Most thin brick manufactures will provide 90-degree corners, edge caps and corner edge caps to create any brick detailing desired. The most economical approach is to work closely with a thin brick expert who can access a ‘split-tile’ manufacturer. Together, you can create imaginative coursings and details too expensive in a full brick approach.
Thin Brick – Adhered Wall Systems
Thin brick can be adhered to most any interior or exterior wall system. The three most common installation methods are:
- Thick set method when adhering to standard substrate – refer to sketch 1
- Thin set method when adhering to cementitous substrate – refer to sketch 2
- System application adaptable to every substrate – refer to sketch 3.
None of these systems require a concrete foundation, relief angles or support angles above openings. The elimination of these materials is a tremendous cost savings to the overall project. In order to gain an accurate cost comparison between full brick cavity walls and thin brick wall systems, the cost of these materials must be considered.
The first two systems (thick set and thin set) create cementitous barrier walls. By adding a drainage plane, a cavity wall for moisture management can be created.
The thin brick system application works as a cavity wall. The system is designed to allow for water to pass through the wall and out of the system via proprietary weeping mechanisms. Some advantages to these systems include the reduction of required material, simplified labor factor and the potential for 20-plus-year warranties.
Adhered thin brick systems also can be panelized offsite. Using metal or wood stud framing, the entire wall system (including windows, doors, etc.) can be shipped to the site complete. In most cases, these wall panels span column to column and from floor to floor. The result is a precise, pre-engineered building that can be installed more rapidly than field-laid masonry.
Thin Brick – Cast in Concrete Wall Systems
Cast in concrete wall systems are extremely popular because of their architectural flexibility, speed of construction, durability and low cost. The architect can choose to assemble the system onsite (tilt-up concrete) or choose a prefabricated system from a local manufacturing plant (precast concrete).
The brick appearance is created by utilizing a brick coursing form liner to hold the thin brick in place while the concrete is cast. The embedded thin brick, once cleaned, will give the final appearance of a traditionally laid, full brick wall. Determining the best cast in concrete system for your project can be delicate. The determining factor typically is based on your building’s use, floor plate, overall height and wall design.
Tilt-up concrete’s ability to cast very large pieces in single pours is a tremendous advantage over other wall systems. Panels of 25 feet long by 40 to 70 feet high are commonplace. Some of the advantages of precast concrete solutions include plant quality control, reuse of molds and concrete mix consistency. Therefore, even though the material performance characteristics are the same, the project-specific requirements will favor one system over the other.
Thin Brick – The Greenest Systems
Cast in concrete systems have proven to grade exceptionally well in the environmental and economical categories by encapsulating insulation and eliminating all thermal breaks. The thermal images shown above demonstrate the differences between a brick on metal stud cavity wall and the fully insulated concrete wall panel. By eliminating all metal ties and thermal breaks, the insulated concrete panels can increase your R-value significantly.
The insulated concrete wall system does not require any interior studs or insulation. All your mechanical needs can be cast into the panel and the interior panel surface can be a smooth finish to resemble gypsum board. All you need to do is paint the wall. You can save the entire cost of the interior system and add this savings component to your LEED certification.
A growing segment of the residential and commercial marketplace is discovering Insulated Concrete Forms (ICF). This material has the versatility of concrete block (flexible floor plans) with the durability, structural capacity and thermal mass of cast in place concrete. ICF systems provide an interior and exterior layer of continuous insulation without any thermal breaks. Inhabitants of these structures report energy cost savings of 50 percent in most cases. Thin brick can be applied to the ICF wall system using any of the field-adhered methods outlined above.
Ultimately, the designer must recommend the best wall system solution for the owner. Knowing that a thin brick system can give you the desired masonry appearance, reduce structural needs and possess a life expectancy equal to full brick veneers, thin brick is the economical and environmental solution to our 21st century approach to design and construction.
Randy Wilson is the owner of Select Thin Brick, LLC of Columbus, Ohio, a thin brick wall system consulting and distribution company. With more than 20 years of experience consulting with design/construction professionals, Wilson has assisted on countless projects to create innovative solutions to complex wall system needs. He can be reached at randy@selectthinbrick.