Architectural detailing needs to be a shared responsibility between the architect, the manufacturer and the manufacturers engineer. An attachment design by the manufacturer, rather than the architect, is often appropriate for many GFRC projects. The shop drawings will provide the architect and installer an opportunity to review the attachment and make the final detailing.
General Rules for attachment
- GFRC pieces up to about 4 feet x 6 feet can often be produced without an additional structural back-up. The manufacturer will add a stiffener-rib to the product back side for added support. A stiffener usually runs the height of the piece every 24 to 30 inches of the product and has very concentrated glass fiber to cement mix. The product can be attached via a veneer tie and strap, kerf and clip, or similar attachment to the structure of the building.
- Larger pieces or pieces where a stiffener-rib is not appropriate are generally hung with a metal stud back-up. The metal stud system is designed and attached to GFRC piece by the manufacturer as part of the cost of the GFRC on the project. Metal stud back-up is very similar to metal stud framing on most commercial projects, but designed with more precision. The metal stud back-up is usually attached with a grade #2 bolt to the structure of the building. There are occasions where the metal stud framing is welded to the structure. Again the specifications on the welding should follow AWS standards.
- Very large pieces (larger than 8 feet x 20 feet) will have tube steel back-up. The process is much the same as with metal studs discussed above. This back-up will be engineered by the manufacturer.
- AAS is able to provide type of connection that is preferred by customer. GFRC provides flexibility with selection of the connection type.
- Once the connections are selected, the AAS manufacturing and design process is able to pre-engineer the connections support in the products.
- GFRC is much simpler and less expensive to install compared to other much heavier stone products. GFRC installation doesn’t require extensive support structure and heavy construction equipment at the project site.
- AAS GFRC products provide flexibility to select/use right application of caulk or sealants making it easier for masonry contractors not only in their installation process, but also with long term reliability of the installed projects.