Metal building systems (you may call them pre-engineered metal buildings) have long been favored for their strength, durability, and cost-effectiveness. However, one crucial aspect that often goes unnoticed is the insulation system. Proper insulation is essential for reducing energy consumption, maintaining comfortable indoor temperature, and ensuring the longevity of these metal structures. Among various insulation materials, fiberglass insulation stands out as a reliable and cost-effective choice. In this comprehensive article, we will explore why fiberglass insulation remains relevant and efficient for metal building systems.

Evolution – Where It Began

The evolution of fiberglass insulation use has progressed significantly since its inception, transitioning from basic single-layer applications with low R-values to sophisticated, multilayered systems that offer enhanced thermal performance and energy efficiency. Initially, fiberglass insulation was available in the form of batts or rolls, designed to be sandwiched between framing members and the roof or wall panels. While this is still a primary method of insulating a metal building, today’s energy codes have required the development of different solutions.

Over time, advancements in manufacturing and material science have led to the development of higher density fiberglass insulation products and more efficient installation techniques. Innovations include the introduction of multilayered systems, in which the installer utilizes two layers of fiberglass to further enhance performance. Modern fiberglass insulation systems often incorporate vapor barriers, reflective coatings, and other materials to address issues such as moisture control and radiant heat transfer. These systems are designed to maintain their R-value over a wider range of temperatures and conditions, ensuring consistent performance throughout the year. Unlike the single-layer fiberglass mentioned in the previous paragraph, these systems utilize the framing cavity, filling it with fiberglass to improve thermal performance.

Code Requirements

The American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) and the International Code Council (ICC) play crucial roles in developing energy codes in the United States. ASHRAE develops standards like ASHRAE Standard 90.1, which sets minimum energy efficiency requirements for commercial buildings and large multifamily housing. This standard is continuously updated through a consensus process involving industry experts, government representatives, and other stakeholders. The ICC publishes the International Energy Conservation Code (IECC), which includes energy efficiency requirements for both residential and commercial buildings. The IECC is updated every 3 years through a public consensus process, allowing for broad participation from various stakeholders. These organizations ensure that energy codes evolve to improve energy efficiency, reduce environmental impact, and promote sustainable construction practices.

Code agencies continue to value and require the properties of fiberglass insulation as a viable solution for achieving energy efficiency goals. The great news is that fiberglass insulation systems are able to meet all current energy codes.

As states adopt new codes, you will begin to see more requirements around air infiltration. This topic is becoming more relevant with each new code cycle. You should know that fiberglass insulation systems have been put to the test and perform to the current code requirements.

Benefits

Here are some of the benefits of fiberglass insulation and why it is a practical choice for metal buildings.

• Fiberglass insulation is budget friendly, making it an attractive option for metal building projects. Although it is budget friendly, you are not sacrificing performance.
• Fiberglass stands out for its low installed cost per R-value. R-value measures the material’s thermal resistance.
• With the shortage of skilled labor and escalating labor costs, fiberglass insulation could be considered “user-friendly,” with its specific product markings and the general ease of handling. Its flexibility allows it to fit into irregular spaces (allowing for a filled cavity). The flexibility and ease of handling helps minimize installation costs.
• Its durability is almost unprecedented. Unlike some materials that are prone to absorbing moisture, fiberglass insulation remains unaffected. It does not promote mold or mildew growth, ensuring a healthier indoor environment. Properly installed fiberglass insulation can last for decades without significant degradation, underscoring its cost-effectiveness over time.

Fiberglass insulation can contribute significantly to achieving, or exceeding, energy efficiency goals. The thermal performance of fiberglass insulation effectively reduces heat transfer, keeping indoor spaces warmer in winter and cooler in summer. A metal building system’s insulating properties help maintain a consistent temperature, enhancing occupant comfort, and can lead to reduced heating and cooling costs.

Tested

Metal building insulation must be tested for a myriad of safety and performance characteristics. The American Society for Testing and Materials (ASTM) is a primary agency for the development of standards that help enhance the performance of products and foster the confidence in those products that you, as both a consumer and/or architect/engineer/specifier, buy and use.

A couple of examples are:

• ASTM E84 is the “Standard Test Method for Surface Burning Characteristics of Building Materials.” This standard should be used to measure and describe the properties of materials, products, or assemblies in response to heat and flame under controlled laboratory conditions. Fiberglass by nature is noncombustible; however, when you add a facing and some sort of adhesive material, it is important to test the final produced product.
• ASTM C991 is the “Standard Specification for Flexible Fibrous Glass Insulation for Metal Buildings.” This specification covers the classification, composition, and physical properties of flexible fibrous glass insulation for use in metal building roofs and walls.

NIA 404 Standard

NIA and its Metal Building Laminator Committee* understand the importance of safety and performance characteristics related to the products we provide the market. The committee meets regularly and recently published a revised standard, “NIA Certified Faced Insulation Standard (Version 404.2–2024).” The specifics of the standard can be found at 404.2–2024

Metal building systems continue to be a popular choice for the one- and two-story commercial and industrial construction markets, since these projects require materials that are engineered to keep pace with constantly evolving design concepts and aggressive energy codes. As a committee, we are committed to providing a fiberglass insulation solution that meets the industry safety and quality requirements, as well as the most stringent energy efficiency codes.

This issue contains articles on the various aspects of metal building insulation systems and their benefits. If you need more information or have questions on utilizing certified faced fiberglass insulation solutions on your next project, reach out to NIA and our Metal Building Laminator Committee members at membership@insulation.org.

* A committee that meets within NIA, which is a not-for-profit service organization dedicated to meeting the needs of mechanical and specialty insulation contractors, distributors, fabricators, manufacturers, and metal building insulation laminators.