Home Builders Weigh Challenges of Alternate Materials

As home builders throughout the United States grapple with building material price surges, and shortages or delays for certain orders, many are exploring alternative products to complete or start projects.

According to a recent article, some builders are constructing homes from natural materials like 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.

Using these alternative materials, however, 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.

In addition, the long-term effects and unintended consequences 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 harbor mold. It was not too long ago that mold was a high liability issue for builders and property owners. The use of rapidly renewable materials — products that can be produced naturally and quickly from nature — is a key component of green building. These are 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. In a 2007 study for his Master’s thesis at Texas A&M, Aaron Cooper exposed samples of rapidly renewable materials used as exterior wall insulation products to different moisture levels 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.

Cooper notes in his paper, “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.”

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.