As home builders throughout the United States are grappling with building material price surges, and shortages or delays for certain orders, many are exploring alternatives products to complete or start projects. For example, according to a recent article, some builders are constructing homes from natural materials such as rammed earth, adobe brick, and volcanic rock. In addition to being readily available on site there may be heating and cooling benefits due to the natural insulation provided by these materials. The article cautions, however, that using these alternative materials may come with added challenges such as higher costs due to a need for skilled labor, delays by home inspectors who may be unfamiliar with the techniques and methods of construction, and energy consultants who might have difficulty calculating the value of homes with these materials. See Home Builders Are Turning to Natural Materials to Get Around Supply Chain Problems; There are advantages to buying homes made with natural materials, but expect to pay a premium, Alanna Schubach, Mansion Global (March 25, 2022).
Another caution, not addressed in the article, however, but one that should be heeded by builders considering alternative materials, is the unintended consequences that might result from using alternative products, whether they are natural products or any others. The long-term effects of material use should not be ignored.
For instance, it has been reported that earthen materials are known to contain numerous organic substances and can also harbor mold. It was not too long ago that mold was a high liability issue for builders and property owners. Similarly, the use of rapidly renewable materials - products that can be produced naturally and quickly from nature - is a key component of green building. They are also cellulose or carbohydrate-based products and as such are typically optimal food sources for mold in the presence of moisture.
To avoid mold, it is important to understand the relationship between construction materials and their susceptibility to mold in the presence of moisture. “Buildings will never be designed, built, maintained, or utilized perfectly; and weather and natural disasters cannot be predicted. The one thing we can have complete control over, the materials within the building, should be selected wisely.” See Mold Susceptibility of Rapidly Renewable Building Materials Used in Wall Construction, AM Cooper, Master's thesis, Texas A&M University (2007) (Samples of wool, cork, straw, and cotton-- rapidly renewable materials used as exterior wall insulation products--were exposed to different moisture amounts in an encapsulated environment, representing the environment within a wall cavity when exposed to water from pipes, leaks, condensation and absorption, or from initial construction. The samples were monitored over time for mold growth).
Mold-related issues are just one example of the potential for unintended consequences from the use of alternative materials. Carefully reviewing building material choices in advance may help eliminate non-conforming building materials, returns and possibly disputes. NAHB has developed a guide, Assessing Building Materials, for builders who may not have their own review process for gathering information from manufacturers and distributors when considering the selection of new building materials.
The guide is intended to arm members with the most important factor when evaluating new materials or products: information. Use the guide to step through the information collection process to make an informed decision on deploying new products or materials. The guide is not intended to be exhaustive or all-inclusive, but it will help builders ask the right questions and seek the most relevant information.
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