What to Know About Building Code Insulation Requirements

Building codes are used to make sure that buildings are built safely and energy efficient. A local jurisdiction’s building codes set the minimum for how well a building must be constructed. Building codes can evolve as information changes or new materials become available. Understanding the requirements for insulation keeps you adhering to the code and can save you time and money.

Building Code Standards

Building codes are adopted by local towns and cities and can vary all across the nation. These codes are typically adopted from standards published by knowledgeable organizations in the industry. Some municipalities adopt new standards into their building codes much quicker than others and are something any building owner should be aware of.

What Organizations Create Standards?

Some of the most popular organizations for creating standards are:

• American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE)

• North American Insulation Manufacturers Association (NAIMA)

• American Society for Testing and Materials (ASTM)

• International Energy Conservation Code (IECC)

As these organizations publish standards, local jurisdictions review their building codes and decide what new standards they want to adopt into their building codes. 

Standards That Affect Insulation

Some standards that are often used in building codes to set requirements for insulation are ASHRAE 90.1, NAIMA 202-96, and ASTM C 665. 

NAIMA 202-96, for instance, is a certification that insulation manufacturers use to ensure that their products comply with the minimum requirements of that standard. Inspectors from the National Association of Home Builders (NAHB) make quarterly unannounced visits to the factories that produce certified insulation. The inspectors review quality control procedures, records, and randomly test products to ensure the insulation meets the requirements of the certification.

Standards like ASHRAE 90.1 prescribe what types of insulation must be used when building different kinds of buildings. These standards define items like “continuous insulation” and break down the amount of insulation required for different climate zones in the U.S. These standards help ensure that everyone is speaking the same language when it comes to insulation and building standards.

What Insulation Meets Code Requirements?

Certified products help you know whether or not a certain product will meet code requirements. Insulation is not always produced in the same way for use in all different applications. For example, NAIMA 202-96 Certified Metal Building Insulations are fiberglass insulations intended for use in metal buildings, specifically. While they can sometimes be used in different applications, certifications help you know that a product will meet the requirements of a given standard.

Breaking Down ASTM C 665, Including Types and Classes

ASTM C 665 is an additional certification used for mineral fiber blankets that quickly lets you know if an insulation type will be acceptable. ASTM C 665 breaks insulation down into Type I, Type II, and Type III.

ASTM C 665 Types

Type 1

Blankets without membrane coverings. Unfaced insulation.

Type 2

Blankets with a non-reflective vapor retarder membrane covering one principal face. Classes A, B, and C are typically kraft-faced.

Type 3

Blankets with a reflective vapor retarder member covering one principal face. Class A, B, and C, foil-faced. 

ASTM C 665 Classes

Additionally, there are three different classes (A, B, and C) that describe how membranes are faced on the insulation.

Class A

Membrane-faced surface with flame spread of 25 or less. For use in exposed applications meeting building code requirements.

Class B

Membrane-faced surface with flame propagation resistance critical radiant flux of 0.12 W/cm2 or greater.

Class C

Membrane-faced surface not rated for flame propagation resistance (for use in non-exposed applications only)

A building code will prescribe what is minimally acceptable, allowing you to find a material that meets or exceeds the requirement then easily. Ultimately, building codes provide a minimum for thermal effectiveness, fire resistance, and moisture resistance that all new buildings must adhere to.

Polyiso Exceeds Expectations and Achieves Strict Code Compliance

Because of polyiso’s exceptional performance, it often exceeds the requirements laid out in building codes making it an easy choice for code-compliant construction. Notable building codes polyiso achieves are ASHRAE 90.1, NAIMA 202-96, and ASTM C 665. 

And while the great benefits of polyiso have been understood and employed for roof installations, Rmax polyiso is also the superior choice for walls and below-grade applications. Let’s take a look at what makes polyiso so effective:

Thermal Conductivity

The higher an insulation’s R-value, the better it is at insulating. Polyiso boasts an impressive 6.5 R per inch value that demonstrates its low thermal conductivity. Meeting the minimum R-value required by code requires a thinner wall when using polyiso over other insulation types.

Polyiso also provides exceptional strength and dimensional stability which makes it great for use as continuous insulation. More standards are beginning to require continuous insulation layers on buildings because they outperform cavity insulation techniques. When buildings are built with cavity insulation, the studs in the wall act as thermal bridges allowing heat to “leak” around the insulation and through the studs. Continuous insulation avoids these issues by applying a continuous layer of unbroken insulation on the outside of the building’s walls, just behind the exterior cladding.

Fire Resistance

Polyiso is a type of plastic known as a thermoset. Unlike other insulation types, when polyiso is exposed to fire and intense heat it chars instead of melting. Polyiso makes for a highly resilient insulation material that can help limit damage in case of a fire. As standards raise the minimum fire ratings that insulation types are allowed to have, polyiso will be in a great position to meet and exceed those requirements.

Moisture Resistance

Polyiso comes in a rigid foam board format, and it can be laminated to foil facers during manufacture. The foil face provides a built-in vapor barrier for reducing the amount of water vapor that can be transmitted through the insulation. Some insulation types are very permeable to water vapor and require additional costly vapor barriers to be added to the wall during construction to ensure the building meets code requirements.

Utilize the Best Performing Polyiso Insulation with Rmax

Rmax polyiso is high-performance insulation available throughout the USA at a competitive price. Using quality materials ensures a well-finished building and avoids headaches worrying about being code compliant. To learn more about Rmax polyiso’s extensive building code approvals, reach out to our team of insulation experts today.

EPS vs XPS Insulation and a Better Alternative

When deciding on which insulation type to use, it can be difficult to figure out the differences between all the options on the market. Knowing what makes each insulation type special will help you make an informed decision. Insulation is one of the most important parts of your building, so it is a decision you will want to get right.

The Importance of Insulation

Insulation is incredibly important to a building’s performance and longevity although it often does not get the credit it deserves. The main role of insulation is to slow down the transfer of heat into and out of the building. By slowing down this rate of heat transfer, the building’s HVAC does not have to use as much energy to keep the building comfortable.

In addition to energy efficiency, some other benefits of insulation are:

Noise Reduction

Buildings with little or no insulation tend to be very loud. Insulation reduces the noise from loud sounds outside and prevents sound from being able to echo off the building’s walls internally. Without insulation, noise can reverberate throughout the building. Insulation acts to dampen these sounds, keeping them from getting louder and making your building more enjoyable to be in for all occupants. 

Fire Resistance

Code requirements require insulation to pass a minimum fire rating test. Buildings with insulation make it harder for a fire to spread throughout the building. Not only can this reduce structural damage in case of a fire, but it will also reduce the likelihood of fire-related injuries to building occupants.

Thermal Comfort

Insulation helps to slow down heat transfer into and out of the building, and also keeps the temperature in a building more consistent. Without proper insulation, a building is more likely to have hot and cold spots throughout. Thermal comfort keeps occupants more productive and reduces the variability in how your HVAC equipment operates.

EPS and XPS: What’s the Difference?

Expanded polystyrene (EPS) and extruded polystyrene (XPS) are both popular forms of insulation and while similar, they do have their differences.

Composition

XPS is made via an extrusion process, resulting in a closed cell structure and a smooth layer on the top and bottom sides of the board. The closed cell structure of XPS prevents water penetration into the insulation and gives XPS enhanced strength and durability

EPS is made using beads of foam instead of an extrusion process. The beads are placed into a mold and then heated to fuse them. Since voids can occur between the beads, the insulation is not a closed cell board and is less resistant to water.

Thermal Conductivity

One of the key parameters for any type of insulation is its thermal conductivity. XPS and EPS are both popular insulation types because they both have low thermal conductivity. EPS has pockets of air trapped inside the foam board, so XPS typically outperforms EPS. High-density EPS is closer in performance to XPS, but XPS still usually performs better.

Compressive Strength

For some applications, the insulation’s compressive strength becomes very important. Concrete floors, flat roofs, foundations, and cold storage all put more stress on the insulation. XPS is typically stronger in compression than EPS, requiring thicker,  higher-density versions of EPS to match XPS insulation’s performance.

Water Vapor

Often a deciding factor for when to use XPS versus EPS is the ability to resist water vapor diffusion. Water vapor can travel through insulation and into the building. The closed-cell nature of XPS makes it much more difficult for this to occur. In wetter locations, XPS is usually selected over EPS.

Polyiso: the Better Alternative

Polyisocyanurate (polyiso) provides a superior alternative to both EPS and XPS insulation. Polyiso is a completely different kind of plastic, a thermoset instead of a thermoplastic. When exposed to high heat, XPS and EPS soften and melt. Polyiso, on the other hand, simply chars.

The structure of polyiso tends to be stronger than XPS or EPS due to the bonds of its chemical makeup.  Polyiso has a three-dimensional network of bonds or cross-linking, that gives it both strength and high-temperature durability. This durability helps polyiso keep its shape and high performance better than XPS and EPS.

Polyiso is higher-performing insulation with thermal conductivities better than XPS. Even with exceptional performance, polyiso is still comparable in cost with XPS and EPS, based on its lower price per R-value per inch. Polyiso matches or exceeds the performance of both XPS and EPS including being more sustainable for the environment, having higher thermal performance, greater fire resistance, thinner wall profiles, and better moisture management and air infiltration reduction.

Find the Best in Polyiso with Rmax

At Rmax, our mission is to take the best polyiso insulation available and maximize its performance even further. When choosing the insulation for your building, reach out to our experts at Rmax today to learn more about why Rmax’s polyiso wall insulation is the best choice.

Why insulate the exterior side of the foundation wall?

All building foundations come in contact with the ground. Wherever a building is located, water, temperature, air, and soil on the foundation can impact the performance and integrity of the total structure. Continuous polyiso rigid foam insulation effectively reduces foundation energy loss and protects against moisture problems.

ADVANTAGES OF INSULATING
EXTERIOR VS. INTERIOR SIDE OF THE WALL

• It does not reduce the usable building space

• Completely continuous for optimal energy efficiency

• Mass of foundation within the insulated building envelope

• Warm wall solution minimizes condensation on the interior side of the wall

• Protects the waterproofing

• Eliminates freeze/thaw on structural elements

• Easiest install

Supply chain woes? Don’t compromise on the long-term benefits of building energy efficiency.

Posted By PIMA

To solve today’s supply chain challenges, should we ignore the building energy code? No, accepting less today in return for higher costs tomorrow is no strategy at all.

The inconvenient truth for critics of building energy codes is that compliance with current versions of the IECC and ASHRAE 90.1 serves as the most cost-effective mechanism for reducing building energy use and the associated carbon emissions generated from powering schools, office buildings and other commercial spaces. While today’s supply chain challenges are certainly frustrating, ignoring the energy code eliminates long-term improvements in building energy efficiency and saddles building owners with higher energy costs for decades to come.

Energy codes provide minimum standards for new and existing buildings. One way the codes help improve the performance of existing buildings is by requiring that roof replacement projects comply with code minimums for building envelope insulation. A recent study by PIMA and the consulting firm ICF International confirmed that energy code-compliant roof replacements are life-cycle economical under various conditions even when subjected to higher incremental installation costs and discount rates. For example, a primary school located in Climate Zone 5 (Chicago) can experience an estimated 9% savings in annual whole building energy use by installing a roof replacement with code-compliant levels of insulation. These savings will continue to compound year-over-year during the roof’s service life.

Simple, short-term solutions can be appealing in times of duress. In the case of building energy efficiency improvements, a short-term focus that sacrifices long-terms benefits is a bad deal for building owners. Check out the PIMA study for more information on how installing an energy efficient roof today is the right decision for your project or building.