New Guidance Helps Insulate You from Poor Walls and Attics

Filed in Codes and Regulations, Home Building by on June 15, 2017 0 Comments

Foam insulation Today’s builders can select from an increasing number of insulation products to meet the high R-values specified by current energy codes. And installing these products correctly is key to providing energy-efficient and durable wall assemblies and comfortable indoor conditions for home buyers.

Thankfully, NAHB is here to help.

Our Construction Technology Research Subcommittee worked with Home Innovation Research Labs to produce a Tech Note covering Installation of Common Insulation Types: Wood Frame Walls and Attics.

This Tech Note reflects industry best practices for the installation of fiberglass batts, blown fiberglass (both directly into wall cavities or on attic floors or behind netting), dry-blown and damp-spray cellulose, and open- and closed-cell spray polyurethane foam. These reflect the most common insulation products selected as reported in Home Innovation’s Annual Builder Practices Survey.

Included in the Tech Note are descriptions of the three insulation installation grades documented in the ANSI/RESNET/ICC 301 Standard for the Calculation and Labeling of the Energy Performance of Low-rise Residential Buildings using an Energy Rating Index.

A Grade I installation is required under the air sealing and insulation provisions of the 2015 edition of the ICC/ASHRAE 700 National Green Building Standard™.

Other highlighted practices include recommended drying times for cellulose insulation, and ventilation and re-entry recommendations when SPF insulation is applied.

The new Tech Note joins seven others available in our TechNotes: Best Practices for Home Builders series. Other topics include Whole House Mechanical Ventilation, Building Air Tightness, and Vapor Retarders.

These 4- to 6-page brochures provide summaries of building code requirements and document industry-recommended best practices. Graphics illustrate key code provisions and practices, and references are provided for additional information.

These resources can help builders understand today’s complex energy and mechanical codes, and select from the ever-increasing array of products and systems to meet stringent code requirements. The best practices in the Tech Notes can help builders avoid problems related to lower energy performance, moisture and mold in wall and ceiling assemblies, and poor occupant comfort that can lead to home owner complaints and callbacks.

For more information on the Tech Notes series or other building code-related research, visit or contact Gary Ehrlich at 800-368-5242 x8545.


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