The International Residential Code (IRC) prescribes only a few conventional buildings materials for use in building a home—concrete, dimensional lumber, masonry, and light-gauge steel framing. Any other materials must be approved according to “Alternative Materials and Methods of Construction” (see Can I Build My Home Out Of…?) in IRC Section R104.11. Following the testing provisions may be especially daunting for the first-time builder, but it can be done.
There are three ways to test materials: performance-based testing; product evaluation; and analysis by a registered design professional (RDP), such as an architect or engineer.
Performance tests are common for natural materials. Performance tests are a common means of accepting natural materials that are not listed in the prescriptive portions of the IRC. Straw bale, adobe, bamboo, cork, etc. can be acceptable for use if they meet the performance-based provisions of the International Code Council (ICC). For instance: You want to build a home out of straw bales, so you would follow the “ICC Performance Code for Buildings and Facilities,” which would validate the efficacy of the material. The steps in this process are understood by an experienced architect or engineer. So, again, start with an RDP.
Product evaluation is the approach most often used on products that are designed and manufactured because it paves the way for more rapid acceptance by building officials. Essentially, the manufacturer will have its new product tested and evaluated by an independent laboratory using testing criteria that is unique to the material or its intended use. When the product passes these independent tests, it then is listed by an approved agency according to certain conditions.
For example, the International Evaluation Service (IES), a subsidiary of the ICC, is a national leader in evaluating product conformance with code. IES performs technical evaluations of building products, components, methods, and materials to make sure they meet the requirements of the code. A report is then issued and made available to the building official confirming that the material or method of construction meets the intent of the code. It is a common means of approval that is acceptable to most building officials.
An independent analysis by an RDP is another alternative that is commonly accepted by building officials. The engineer or architect would follow accepted standards of practice in their field to demonstrate that the material meets the health and safety intent of the code. The RDP would perform the necessary research on the product or material, calculate the required strength for its intended purpose, and demonstrate its efficacy. The RDP would likely do this by performing field tests or at least analyzing the results; then, through engineering analysis and calculations, show the material’s compliance. The RDP would most likely be expected to affix the professional seal to the analysis or design work before it is submitted to the building official for consideration.
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