Making a Difference with Sustainable Insulation: A Comprehensive Guide

Your next project has the potential to make a difference. That’s because buildings have a massive impact on the environment—encompassing everything from waste in landfills to carbon dioxide emissions to energy consumption.

Even if you’re not looking to get your project LEED certified, you can still choose more sustainable materials so that your building could potentially produce a net positive rather than a net negative effect on the world. That’s what sustainability is really all about; living in harmony with the natural world. This is your opportunity to choose materials that are more compatible with nature. Let’s find out how.

How Buildings Play a Role in Creating a Sustainable Future

None of us live forever, but it’s likely that our buildings, and the effects of how we live today, will outlast us and continue to impact future generations for years to come. 

While historic buildings have lasted hundreds and some even thousands of years if well-maintained, today’s buildings aren’t lasting so long. The estimated lifespan of a college campus building is 75 years, and most single-family homes are lucky to last a hundred.

One simple way to make a difference is by picking the right building materials. By choosing more durable building materials, you can fortify your building’s defenses against the elements and improve the longevity of the structure. Although your structure may not last thousands of years, it’s still important to consider the environmental impacts during its lifespan.

Buildings, both residential and commercial, affect the environment in several ways, including:

• Energy Consumption

• Carbon Emissions (read more here)

• Resource Consumption

• Construction Waste

Luckily, designers and builders can work together to reduce the negative impact caused by these factors. One major way to reduce the building’s impact is reducing energy consumption by choosing sustainable insulation materials. When you reduce unintentional heat exchange (heat loss) through the building envelope, you affect the degree to which your building impacts the environment. You’ll want to select sustainable insulation that adequately insulates the building envelope in order to increase energy efficiency.

What is Environmentally Sustainable Insulation?

So, how do you find and select building materials that are truly environmentally sustainable? 

Environmental Product Declarations

One way is to review Environmental Product Declarations (EPDs). These documents are provided by manufacturers and third parties and provide the results of studies that show the environmental impact of the specific product. 

For example, the Polyisocyanurate Insulation Manufacturers Association (PIMA) has provided third-party EPDs for polyiso showing that over a building’s lifespan, polyiso has 47x energy savings when compared to the energy required for the following processes:

• Initial manufacturing

• Transportation to job sites

• Lifetime maintenance

• Decommissioning and disposal

LEED-Certified Products

LEED credits worksheets, provided by manufacturers, are another way to understand how a building material can impact the environment for the better. These documents name the sustainable category and give a description of how the material meets the LEED requirements. Sustainable building insulation will typically possess the potential to meet the following LEED credits:

• Energy & Atmosphere Credit (EA)

• Materials & Resources Credit (MR)

• Environmental Quality Credit (EQ)

More Considerations for Finding Sustainable Insulation Solutions

According to the EPA (Environmental Protection Agency), when shopping around for the best sustainable insulation for your project, the primary factors to consider are the following:

1. R-value per inch (Higher is better)

2. Limited or no toxins or VOCs

3. Recycled content

4. Low emissions

5. Low energy required to manufacture (embodied energy)

6. Sustainable sourcing of raw materials

7. End of life disposal options including recycling or reusing

You can identify products that qualify by locating ecolabels, including certifications such as Intertek Clean Air for indoor air quality, GREENGUARD for chemical emissions, and ENERGY STAR® for energy efficiency. 

Types of Sustainable Insulation

Insulation materials that rank high on the sustainability scale include rockwool, concrete, and polyisocyanurate. Polyiso is one of the most sustainable insulation materials in board form because it boasts the following properties:

• High thermal efficiency (High R-Value) 

• Zero ozone depletion potential

• High recyclable content 

• Negligible global warming potential

Examples of less sustainable insulation products include styrofoam, fiberglass, and spray foam, which can have a negative impact on the environment in terms of ozone depletion, hazardous materials, or harmful emissions. 

Rmax’s Commitment to Sustainable Thermal Insulation

Rmax is a leader in the industry when it comes to shifting toward more sustainable practices in the construction industry, including the manufacturing of more environmentally-friendly building materials. 

As evidence to this claim, Rmax polyiso products currently meet several criteria for LEED credits. The majority come from enhanced energy performance offered by polyiso products. One earning possibility even includes innovative solutions, such as the Rmax® ECOMAXci® Wall Solution that acts as an air, water, vapor, thermal and hygrothermal barrier all-in-one.

Read more about the company’s sustainable design initiatives and reach out to your local Rmax representative to find sustainable insulation solutions for your next project!

Polyiso Insulation vs. XPS: A Comparison

Choosing the right building materials for your construction project can make or break your finished masterpiece. If you don’t get things right during the construction phase, fixing them later becomes a costly undertaking. Because it’s often concealed in walls and other hard-to-reach spaces, one of the critical components you’ll want to get right from the start is your insulation selection. 

Insulation directly impacts your building’s:

• Energy bill

• Comfort level

• Material integrity

Without insulation to help regulate temperature, moisture and condensation can form, and will promote mold growth inside your building and wreak havoc. Maximize your insulation’s potential by using the right type for the job. 

Types of Insulation Used in Construction

Insulation comes in many different sizes, shapes, and forms. Here are the common types of insulation used in construction today:

• Fiberglass

• Mineral wool

• Polyisocyanurate 

• Polyurethane

• Polystyrene

• Concrete

These insulating materials can come in many forms, including loose fill, boards, batts, rolls, blocks, or spray foam. In this article, we’ll compare two of the common foam types that are installed in modular board form: XPS and polyiso insulation.

What is XPS?

Extruded polystyrene, or XPS, is a foam-based synthetic polymer material that has been melted and compressed into board form. Think of the packing materials for large, delicate items like a flat-screen TV or computer—this packaging is sometimes made of XPS.

The name you’ll hear on jobsites is “blue board.” That’s because the color is often baby blue, or sometimes pink. In construction, XPS is commonly used at the foundation or floor level and in other areas with high moisture.

What is Polyiso?

Polyisocyanurate, or polyiso, is another foam-based insulating material that is sandwiched and pressed between facers to create the board form. This process is called lamination. Consider an insulated garage door—the insulated panels are probably made from polyiso. 

On job sites, polyiso is referred to as iso. You’ll find iso used over large portions of buildings, including wall assemblies, flat roof systems, and insulated panels. 

Now, let’s take a look at a comparison of XPS to iso insulation.

Comparing XPS vs. Polyiso Insulation

Below, we’ll compare and contrast the different insulation properties of these two building materials.

Closed-Cell Foam Structure

While the chemical makeup of XPS and polyiso are very different, they do share some of the same material properties. For instance, both are a closed-cell foam composition. 

Closed-cell means that the individual air bubbles that are inherent to the manufacturing process of these foam materials are closed and separate from each other. In other words, air cannot move from one bubble to the next inside the foam structure. This helps increase the thermal insulating value, improves moisture resistance, and enhances dimensional stability.

Thermal R-Value

Since the main purpose of insulation is thermal resistance, or keeping heat from escaping, let’s compare the thermal resistance capabilities of XPS to iso insulation. Typical extruded polystyrene rigid foam boards carry a minimum R-5 per inch, while polyiso boasts a better performance rating at R-6 per Inch. That means a 2” thick XPS board will have at least R-10 and a 2” thick polyiso board wins with R-12. A thinner profile with higher insulating value can lead to big savings on overall wall thicknesses and other building materials.

Versatility in Facers

One noticeable difference when comparing polyiso insulation to XPS is in the facers. 

XPS is unfaced, meaning that the entire makeup of the board is made of a single material—extruded polystyrene. This can limit the applications, considering that XPS is often incompatible with adhesives.

Polyiso, on the other hand, is laminated to facer material on both sides of the foam. That means that the material you see on either side of iso differs from the foam core, and expands the physical properties available from the product.

Polyiso facers can be made of the following materials:

• Coated Glass Fiber Mat Facers (Rmax Durasheath® for the building envelope)

• Glass Fiber Reinforced Aluminum Facers (Rmax ECOMAXci® FR for exposed exteriors)

• FR Treated Plywood (Rmax ECOMAXci® FR Ply for cladding attachment)

• Reinforced Aluminum Foil Facers (Rmax Thermasheath® for the building envelope) 

High-Temperature Applications

Building envelope surfaces, including walls and roofs, can reach extremely high temperatures well above the ambient air temperature. That means you’ll want to pick materials that can stand the heat inside your walls and roof. 

When comparing xps to polyiso insulation in heat resistance, polyiso outperforms extruded polystyrene. Due to being a thermoplastic material, under extreme temperatures, XPS loses all dimensional stability and melts back into its molten components. In contrast, polyiso is a thermoset material that will not melt under the same high temperatures and remains stable.

Choosing the Right Insulation for the Job with Rmax

Picking materials for your construction project can be overwhelming. If you need help deciding which insulation to specify to meet your specific project needs, Rmax can help. 

Reach out to your local Rmax representative today to narrow down your options.

Florida Building Code Insulation Requirements

There’s a reason that snowbirds flock to Florida each winter. The warmer temperatures and humid climate provide relief from the cold and dry winters that many of them have to face throughout a big chunk of the year. The unique climate of Florida is only shared with a few other locations, such as South Texas and the southern tips of the states between Florida and Texas.

The unique climate also brings unique challenges when it comes to construction and building design requirements. With such a large cooling load, high humidity, and coastal considerations, structures in Florida require some special attention. 

That’s where building codes come in. Brush up on the fundamental code requirements in the state of Florida to make sure your next project is up to code.

The Basics of Florida Building Codes

Building codes are a set of guidelines that help keep buildings safe, accessible, and energy efficient. 

Common Building Codes

There are many different building codes. Here are a handful of some different realms that building codes can cover:

• Energy Code

• Structural Code

• Life Safety Code

• Plumbing Code

• Fire Code

• Electrical Code

• Accessibility Code

• Zoning Code

A Focus on Energy Code Requirements 

For the purpose of this article, we’ll be focusing on energy codes for Florida. Energy codes are designed with geographical location at the forefront in order to ensure buildings are energy-efficient for the local climate. In other words, the Florida building code roof insulation R-value will vary greatly from the R-value requirements in Maine.

The energy code sets the standard for the following building systems:

• Insulation Requirements

• Heating and Cooling System Requirements

• Windows and Lighting

Florida Building Codes

Generally, building codes are written on a national scale by organizations, such as the International Code Council (ICC), and then adopted at the local level. Florida and other states, as well as local governments, adopt and modify these model codes while also writing their own laws to deal with the various factors impacting local construction.

Florida’s energy code is called the Florida Energy Conservation Code, or FECC. This code, last updated in 2020 as the 7th edition, applies to both residential and commercial buildings. This set of regulations adopts the model code known as 2018 IECC and ASHRAE 90.1-2016 as its basis.

Florida Building Code Insulation Requirements

Before you build in Florida, one of the first steps to planning requires a review of code requirements. Even within the state borders, these code requirements can vary depending on geographical location, particularly for energy codes. The International Energy Conservation Code (IECC) provides a climate zone map as a starting point and the Florida energy code further breaks down this map by county.

Inside Florida, there are two major climate zones, according to the IECC Climate Zone Map. They include:

• Zone 1A: Very Hot and Humid - Includes a handful of the southernmost counties of Florida including Miami-Dade county

• Zone 2A: Hot and Humid - Includes most of Florida

Commercial Buildings in Florida

Florida building code insulation R-value requirements for commercial building envelopes are listed in Chapter 4 [CE] of the FECC and shown in the table below:

*Florida building code attic insulation requirements can be reduced from R38 to R30 if one of the following conditions is met:

• Continuous insulation is used over 100% of the ceiling area and over the top plates at the building eaves.

• There is insufficient space to accommodate the R38 requirement in the roof or ceiling assembly.

Residential Buildings in Florida

Florida building code exterior wall insulation R-value requirements for homes and residential structures are found in Chapter 4 [RE] of the FECC. These values match the similar requirements as commercial structures and are listed below in the table:

*R38 values can be reduced to R30 if one of these conditions is met:

• Insulation continues over the entire ceiling area and over the top plates at the eaves.

• There is a lack of space to meet the R38 requirement in the roof or ceiling.

Insulation Products that Meet Florida Building Code

Insulation is an essential building material required to meet Florida building code. Meet code insulation requirements by choosing materials that pack a punch with high thermal resistance R-values per inch while also meeting testing requirements.

One insulation product category that exceeds both of these prerequisites is polyisocyanurate, or polyiso. Rmax polyiso products offer superior R-value with minimal thicknesses. For example, R30 ceilings can be achieved in less than 5” with two layers of 2.5” Rmax Durasheath® insulation, for a cumulative R-value of 30.6.

Walls and floors can achieve R13 insulation in 2” with Rmax Thermasheath® insulation or ECOMAXci® FR insulation. For an all-in-one solution that combines continuous insulation and air barrier, the Rmax ECOMAXci® FR Air Barrier is an ideal solution.

Meet Florida Building Code with Code-Compliant Insulation

If you’re ready to select your building materials for your construction project in Florida and want to make sure you’re meeting Florida building code insulation requirements, Rmax can help. We offer a wide variety of code-compliant, energy-friendly, and easy-to-install insulation solutions. 

Let our representatives help you today to pick the right products for your project’s building envelope.

Understanding LEED Certified Insulation

If you’re in the construction industry, you’ve probably heard of LEED certification. Whether you know a little or a lot about LEED, it’s hard to know it all. It can be a blessing to have so many methods to achieve LEED-certified status of your building, but it can also quickly lead to information overload. 

If you are looking for ways to earn LEED points—your building’s envelope holds a lot of potential, and your insulation selection is critical to making your building more sustainable. Learn more about the program and LEED insulation requirements below.

What is LEED Certification?

LEED is the acronym for “Leadership in Energy and Environmental Design.” This program was created by the U.S. Green Building Council (USGBC) to inspire construction practices to become more environmentally friendly and sustainable and to make buildings healthier.

Any building type, from new construction to renovations in both residential and commercial settings, can earn LEED-certified status. Each building type has a corresponding scorecard for builders and designers to check off qualifying components in various categories. These categories address the entire construction process and building lifecycle. 

The categories include:

• LT - Location and Transportation 

• SS - Sustainable Sites 

• WE - Water Efficiency 

• EA - Energy and Atmosphere 

• MR - Materials and Resources 

• IEQ - Indoor Environmental Quality 

• IN - Innovation 

• RP - Regional Priority 

Depending on your project type, your scorecard requirements may vary. There are four levels of LEED certification:

1. Certified: 40-49 Points

2. Silver: 50-59 Points

3. Gold: 60-79 Points

4. Platinum: 80+ Points

How can you achieve LEED certification for your project? Let’s take a closer look at how your building’s envelope can bring LEED credits your way.

How to Meet LEED Insulation Requirements

Insulation can help you earn points toward LEED credits in multiple categories. Everything from where you source materials to how well the building materials conserve energy can impact your score.

Since insulation often covers the entire surface area of your building—it’s in your walls, attics, roofs, and sometimes underfoot—it’s critical to take this building material into account for energy efficiency. 

Below are the LEED Insulation Requirements for each category:

Energy and Atmosphere Credits

The Energy and Atmosphere (EA) category has four required credits, including: 

1. Fundamental Commissioning and Verification

2. Minimum Energy Performance

3. Building-Level Energy Metering

4. Fundamental Refrigerant Management

The remaining credits hold the potential for up to 33 points for commercial projects and focus on enhancing energy performance, of which up to 20 points can be reached through altering your insulation. 

Meet the requirements of the EA category by choosing the right insulation products that meet or exceed the ASHRAE 90.1 energy standard and achieve higher efficiencies.

Materials and Resources Credits

The Materials and Resources (MR) category has two required credits:

1. Storage and Collection of Recyclables

2. Construction and Demolition Waste Management Planning

The remaining credits offer up to 13 additional points toward your LEED score in areas that include raw material sourcing, material ingredients, waste management, and building life-cycle impact reduction.

Insulation can help you meet the MR criteria in several ways:

• Low waste accumulation, such as rigid insulation can be cut on-site and fit into any space.

• Insulation can also be reused or repurposed for other projects.

• Certain insulation products contain recycled content.

• Select insulations carry zero Ozone Depletion Potential (ODP).

Indoor Environmental Quality Credits

Insulation can help you earn points toward the IEQ credits on your LEED scorecard. Low-emitting materials, indoor air quality, thermal comfort, and acoustic performance are examples of earning opportunities in this category.

Innovation and Design Credits

You wouldn’t think of insulation first when considering innovation and design, but there is a way to boost your LEED score in this category. Earn up to 5 additional points in LEED-ID by choosing an innovative wall solution such as Rmax ECOMAXci®, which combines an air/weather barrier with continuous insulation in a single layer to virtually eliminate thermal bridging while meeting fire, air, and water code requirements.

LEED Certified Insulation Options

By targeting the above LEED categories and credits, you can begin to narrow your focus to picking the right products for your project’s design. Is there such a thing as “LEED certified insulation”? If so, which LEED insulation should you choose? If not, what do I look for to meet LEED insulation requirements?

The answer is no—there are no LEED-specific materials. Rather, certain materials—including insulation—can help you earn points toward achieving the credits mentioned above. As a component of a whole system, building insulation can help you meet LEED requirements and earn additional points.

When selecting insulating materials for your LEED project, be sure to pick materials that meet code standards at a minimum. For example, Rmax Polyiso insulation meets or exceeds these ASHRAE standards:

• ASHRAE 90.1: Energy Standard

• ASHRAE 55.2: Thermal Environment Design Standard

You can also check Rmax LEED resources to be sure you’re using the most up-to-date references. One reason that polyiso is such a valuable insulation for LEED certified projects is that you can achieve a superior R-value with less material (a thinner profile). 

Polyiso is versatile and can be used around the entire building envelope, from the foundation, up the walls, to the roof. 

Get Help Picking the Right Insulation for Your LEED Project with Rmax

Interpreting the LEED requirements can seem like a monumental task. If you need help navigating and picking the right building materials to achieve LEED certification, Rmax can help. Our experts can tailor a solution to meet your site-specific needs. 

Call or email your local Rmax representative today! your local Rmax representative today!

Best Practices for Basement Wall Insulation

Insulation plays an important role in your building when it comes to regulating temperature and maintaining a comfortable environment. There are many materials with insulating qualities that are used to increase your building’s R-Value—one of them is the ground itself. 

Since the Earth is both a natural insulator and intrinsically reduces air infiltration, you may be wondering if you still need to insulate your structure underground. The answer is yes, but less insulation is required than what you’d expect to use above grade.

In this article, we’ll be exploring best practices for insulating your basement walls.

Supplement the Earth’s Natural Insulating Power

Our first basement wall insulation best practice is to work with the earth, but don’t depend solely upon it to keep your space comfortable. 

If you’ve ever stepped foot in a split-level home, you may notice that the temperature in the basement level tends to be cooler in the summer and warmer in the winter. That’s because the earth helps to stabilize the temperature of the building materials that it touches. An unfinished basement still provides some insulating value, but it is much less comfortable than an insulated space.

Knowing that the earth is going to provide some level of natural thermal resistance, you can supplement in order to get your space in line with the rest of the building. That means reviewing local building code requirements to see what R-Value is required in basement walls. It’s common to see R5 in home construction, but basement wall insulation code requirements can exceed R20 in some areas.

For basement wall insulation, it’s best practice to add at least R5 in insulation. Failing to sufficiently insulate your basement can lead to problems with condensation, musty smells, mold growth, and unnecessary energy loss. 

Interior vs. Exterior Basement Wall Insulation

Our second best practice addresses the placement of your basement wall insulation materials. In new construction, there are two locations where you can install insulation for basement walls. 

1. On the exterior face of the foundation wall

2. On the interior side of the basement wall 

Insulating on the exterior face is mostly done to provide a cushion that protects waterproofing materials from backfilling. Other advantages include added protection on your building’s components from freeze-thaw cycles and simple installation if done during the initial construction phase. This is an example of an exterior basement wall insulation detail.

If you can no longer access the exterior walls without excavation—then interior basement wall insulation systems are a more practical insulating solution. The interior basement wall insulation detail is versatile and allows mechanical fastening to wood furring or metal studs. You can also fasten basement insulation directly to concrete walls with adhesives or specialty masonry screws with plastic washers. 

Choosing the Right Material

Many types of insulation are available to use on basement walls for both interior and exterior applications. Extruded polystyrene, expanded polystyrene, and polyiso are popular choices for rigid insulation boards. Compare the differences in this chart. 

Polyiso just may be the best basement wall insulation because it can be used in both exterior and interior applications, offers a higher R-value per inch, and comes with versatile facers for added protection to match the application.

Here are our top product picks for insulation for basement walls:

Thermasheath® for Exterior Basement Wall Use

This rigid insulation has reinforced foil facers on both sides of the polyiso core. It’s ideal for concealed applications, such as cavity walls and below-grade, to protect your foundation walls and allow water to drain off properly. Read more about it here.

TSX-8510 Insulation

For interior basement wall insulation options, look to products such as TSX-8510 insulation that can double as a finished surface. Both sides feature a glass fiber reinforced aluminum facer sandwiching the polyiso core, and the interior-facing side is also covered with a white modified acrylic coating. This product can optionally be taped and painted for an aesthetically pleasing finish.

Rmax Thermasheath®-XP

Another product that is often used in interior foil insulation basement wall applications is Thermasheath®-XP. This polyiso insulation can be left exposed on either facer. One side is left with a silver reflective clear coat while the other is a white acrylic coat over the aluminum facer. Optional joint tape comes in both a reflective version (R-Seal 3000) and a white version (R-Seal 3000W) to match either side for an attractive finish.

Ready to Pick the Right Insulation for Your Project?

It’s not a matter of whether or not to insulate your basement space, but rather—how? Picking the right wall insulation for basement applications starts with having a plan and then following through with the right materials. Let the product experts at Rmax take a look at your project to help you determine the best course of action for your next remodel or new construction job. 

Reach out to your local Rmax representative today!

What’s the Best Tape for Foam Board Insulation?

If you’ve decided to use foam board insulation for your construction project’s exterior walls, you’ll also need an accessory to go with it: tape for the joints. 

When putting together your building’s enclosure, your system is only as good as its weakest point. That’s what makes sealing the joints between rigid insulation boards so critical. This step keeps air and other elements from seeping through the cracks and into your building’s interior by performing as an air and vapor barrier.

There are many construction tapes on the market to pick from. Choosing the right one for your job ensures that your building’s wall systems can perform as intended. 

Learn more about the best tape for foam board insulation for your exterior wall applications below.

The Difference Between Construction Tape and Insulation Joint Tape

When shopping for the best tape for foam board insulation applications, you’ll need to choose between construction tape and insulation joint tape. Both types of tape are made of an adhesive and a backing material. The difference between construction tape and insulation joint tapes is in the material used for these two components.

Construction tapes are more versatile and can be used for multiple applications outside of just sealing insulation joints, including sealing windows and other penetrations. They can be made of rubberized asphalt, butyl, or acrylic. However, not all construction tapes can double as insulation joint tapes, so you’ll need to verify compatibility with your installation.

Insulation joint tapes are designed specifically and solely for sealing insulation joints for corresponding types of insulations and facers. This type of joint tape is usually made of an acrylic adhesive and features various backing materials—including foil, foam, paper, or BOPP film.

What Is the Best Tape for Foam Board Insulation?

To get the best of both worlds, look for an acrylic-based construction tape that is compatible with your insulation. Acrylic is an ideal adhesive for walls due to its properties of water and mold resistance, as well as adaptability to temperature changes. Other factors to consider when shopping for the best tape for foam board insulation include the following:

• Pressure-sensitive

• Water-resistant

• Mold-resistant

• Moisture-resistant

• Wide enough to cover the joint

• Tough, durable

• Compatible installation temperature range 

• Wide operable temperature range

Rmax R-SEAL Construction Tape

Rmax R-SEAL Construction Tape is specifically designed for use with aluminum-faced polyiso products, including Rmax Thermasheath®-SI and Thermasheath® insulation. It can be used for additional applications such as sealing around windows and door frames, patching, and more. The tape is 3” wide and comes in a 165-foot roll. 

The 3 mil acrylic-based tape is pressure sensitive for maximum adhesion. Additional reasons that Rmax R-SEAL is the best tape for foam board insulation include UV-resistance and weather-tight seal. This tough sealing tape can be installed at extreme temperatures from five below up to 180 degrees Fahrenheit and it is also effective in sub-zero temperatures as low as -40 degrees.

How to Apply Rmax R-SEAL Construction Tape

To install Rmax R-SEAL—first, verify compatibility by testing the adhesion on your material (skip this step for Thermasheath® and Thermasheath®-SI). Once you’ve confirmed compatibility, proceed with these steps:

1. Clean any dirt, dust, moisture, or other debris off your insulation with a dry cloth.

2. Center the tape over the joint or object that you’re taping (extend ¾” beyond the joint’s edge).

3. Affix the tape so that it is smooth and flat.

4. Cut the tape from the roll at the end of the joint with a utility knife. 

5. Flatten out any imperfections with a feathering tool or hand roller.

Rmax R-SEAL 3000 as Adhesive for Insulation Joints

If you’re looking for a foil-backed joint tape, Rmax R-SEAL 3000 is a construction tape that has superior conformability for taping foam board insulation joints. This 2 mil acrylic-based pressure-sensitive tape features foil coating plus a release liner for maximum adhesion even in cold conditions. This tape is 4” wide and comes in a 150-foot roll. 

How to Apply Rmax R-SEAL 3000 Tape

R-SEAL 3000 Tape is installed the same over insulation joints as standard R-SEAL. Clean the surface, tape the joint, and apply pressure for a good bond. Lastly, smooth out any wrinkles with a feathering tool.

Key Points of Using a Good Quality Tape for Foam Board Insulation

You’ll know you’ve got the best tape for foam board insulation when your construction tape has these attributes:

• Excellent adhesion 

• Easy to work with

• Easily cuttable in the field

• Flexible

• Durable

• Long-lasting

• Adequate coverage

Rmax is the Superior Construction Tape for Insulation Joints

As an industry leader in insulation products since 1978, Rmax stays on top to bring better products and accessories to builders as technology and codes change. Check out our full line of accessories which includes tapes, clips, and anchors. We help your projects run smoothly by providing solutions that make the job easier.

If you need expertise in matching the right product to your project, contact your local Rmax representative today.

Continuous Insulation Code Requirements

When planning the construction of a new building, architects and contractors are required to follow a set of standards called building codes. Building codes are guidelines developed at levels as high as the global scale. The codes are adopted and enforced at the local or state level.

Most people think of building codes as a means to ensure safer buildings, however some code requirements go beyond safety and are aimed at also conserving energy. Energy codes are the standards that direct builders on things like how much insulation to use and where to install it based on a building’s geographical location.

As you design your project, if you’re asking, “Is continuous insulation required by code?”—this article answers that question. Find out how energy code requirements will affect your new construction or remodeling project’s use of continuous insulation. 

An Overview of Continuous Insulation Code Requirements

Depending on where your project is located, energy codes will provide a different set of instructions. For example, more insulation is required in colder climates like Alaska as opposed to moderate climates found in the southern half of the U.S. Energy codes divide the country into zones. To understand which set of instructions to follow, you must first identify the zone where your construction project is located. 

The U.S. Department of Energy provides a regional map to help you identify your zone and energy codes. Use this, along with the chart, to help you design appropriate building envelopes for your region.

Types of Insulation

Energy codes don’t specify the type of insulation to use. You can use various types of insulation to achieve the appropriate R-value. Insulation is used to reduce heat loss and stabilize the temperature inside your building. In order to be most effective, insulation needs to be continuous. Various materials can be used to create a continuous insulation barrier around your entire building envelope. Types of insulation frequently used in the building envelope include:

• Blanket: Flexible rolls or batts used in wall or attic spaces

• Rigid: Modular boards used on all faces of the building envelope

• Blown-in: Loose-fill material used in walls, attics, and hard-to-reach places

• Spray foam: Expands to fill wall cavities and in irregular areas

What is Continuous Insulation?

Continuous insulation means that your insulating material is a constant thickness over the entire surface. For example, adding two-inch thick rigid insulation to the entire surface of your exterior wall will provide a continuous R-value.

In contrast, if you only provide blanket insulation between the studs of a wall, the R-value is broken by the studs, which do not carry the same insulating value as the blanket material. This is a non-continuous application.

Likewise, roof liner insulation that is compressed at purlins on the underside of a metal roof does not function as continuous insulation because it fails to embody a constant thickness.

Why Use Continuous Insulation?

Building codes often incorporate continuous insulation because this method improves energy efficiency by eliminating paths where heat can escape through the envelope. Continuous insulation code requirements aim to increase energy efficiency, which in hand, reduces the owner’s heating and cooling expenses over the building’s lifetime.

Other advantages to choosing continuous insulation for your building envelope include:

• An additional layer of moisture protection from water infiltration

• Fast and efficient installation methods

• Code-compliance in wind and fire resistance 

Code Requirements for Continuous Insulation

There are clear advantages to selecting continuous installation for energy efficiency, but is continuous insulation required by code? The answer is yes for some zones, if your local area has adopted the IECC 2021 building code. The 2021 International Energy Conservation Code requires continuous insulation for uninsulated wood frame walls in most climate zones. 

Reviewing the IECC table for your climate zone will indicate the amount of continuous insulation required for each part of the building, including:

• Uninsulated attic space

• Attic Space with existing insulation (3-4”)

• Uninsulated floors

• Uninsulated wood-frame walls

• Insulated wood-frame walls

For example, Kentucky is entirely inside climate zone 4. That means that R15 continuous insulation is required by IECC 2021 for uninsulated wood-frame walls if no other non-continuous insulation is used. Check the table for your location’s continuous insulation code requirements.

Remodeled buildings are not always required to meet the updated energy codes. However, before beginning a remodel project, always check with local authorities to see whether your renovated building will need to be code compliant. 

Rmax Can Help You Pick the Right Insulation

Figuring out code requirements and picking the right insulating system for your project can quickly become an overwhelming headache. Let the insulation experts at Rmax help. Our representatives can review the R-value requirements, check out your design, and pick out a system of products that meet your project’s demands. Reach out to your local Rmax representative today to get your project moving!

Rigid Foam Board or Spray Foam Insulation: Which is Right for Your Project?

When the outdoor air temperature swings from hot to cold, a building’s insulation regulates the temperature inside. The heating and cooling system of a well-insulated building doesn’t have to work as hard - and that results in cost and energy savings for you. Insulation also provides thermal comfort and protection from extreme weather.

Life-safety and energy-efficiency are why building codes, often modified by state code officials to be climate-specific, require that plans for a construction project demonstrate that the proposed insulation for exterior components - roof, walls, foundation - will achieve specific R-values before a building permit is issued. If you’re not familiar with R-values, they indicate how well insulation resists heat loss. The higher the R-value, the better the insulation.

Many types of insulation are available, made from different materials and with different methods of application. Understanding the advantages and disadvantages of each type helps builders, architects, and homeowners make the best choices for their project. Two common types of insulation are rigid foam board and spray foam.

So, how do you decide between them?

Rigid Foam Board Insulation: High R-Values Per Inch

Rigid foam board insulation is foam plastic that has been hardened and formed into sheets that are easy to cut on site. Most rigid foam boards are made from one of three types of plastics: polystyrene, polyisocyanurate (polyiso), and polyurethane.

Rigid foam insulation offers very high R-values per inch of thickness. This becomes important during the project’s design phase when the team is figuring out how to insulate the structure to meet R-values required by the building code. Rigid board insulation increases the wall assembly’s R-value without a significant increase in the overall thickness of the wall. If you want to maximize interior space, keeping the exterior wall thickness to a minimum is essential.

Spray Foam Insulation: Expands to Fill Any Space

Spray foam insulation also offers extremely high R-values. Most often made from liquid polyurethane and a foaming agent, spray foam insulation is applied using a spray can for small cracks and air leaks, or blown in with a pressure-sprayer for larger applications (referred to as “foamed-in-place”). The liquid foam expands and hardens as the material cures. Because its shape conforms to the space in which it is applied, spray foam provides an effective air barrier and is excellent for use in hard-to-reach places, and curved or irregular spaces.

The two types of spray foam are open cell and closed cell. Open cell is lighter and more pliant with foam bubbles that expand, burst, and fill with air. Closed cell is much denser and durable; its cellular structure is closed and filled with gas.

Rigid Foam and Spray Foam: Installation is the Key Difference 

Rigid foam boards and spray foam insulation are installed using completely different methods, which informs the decision of which product to choose.

Because it can be sprayed on, blown in, or poured, spray foam insulation is frequently used in retrofits and remodels to fill in existing wall cavities and awkward spaces like attics, where other types of insulation might be difficult or impossible to install. Spray foam’s high R-value makes it a good choice when an existing wall or roof cavity needs to be brought into energy code compliance.

Rigid foam boards are cut to fit and then mechanically attached to the structure. Often seen in new construction, rigid foam boards can be used to insulate just about any part of the building from foundation to roof. They’re commonly part of exterior wall assemblies, including below-grade walls. Some rigid insulation boards are made specifically to be exposed on interior walls of structures like parking garages or farm buildings. Others are manufactured with air and water barriers on one side, eliminating the need to buy and install additional products.

Advantages of Rigid Board Insulation

Cost

Rigid foam insulation boards are less expensive to install than spray foam. Special equipment and certified installers are typically required to install spray foam insulation.

Thermal Performance

Rigid insulation boards are installed continuously over the studs preventing thermal bridging and heat loss. 

Ease of Installation

Rigid foam can be cut to fit on site, and attached to roof or wall structure. When multi-functional boards with integral air and water barriers are used, additional time and money is saved.

Basement Insulation

Rigid foam boards are very well-suited for insulating basement walls as they are water-resistant and easily installed by adhering them to the foundation walls behind the studs.

Rmax Rigid Foam Insulation Boards

Rmax is a leading manufacturer of polyiso rigid foam insulation boards with a variety of products to suit any insulation need. If you decide that rigid foam insulation boards are the right choice for your project, Rmax is happy to provide more information and answer any of your questions. Contact the experts at Rmax today.

Is Polyiso Insulation Waterproof?

Your building envelope has one job, to keep the elements out. To accomplish this job, the envelope is composed of a system of components that collectively creates the physical barriers called walls, roofs, and floors. Together, these systems separate your structure from the outside and protect it from the elements. 

One element that can wreak havoc on your building is water. That’s why it’s essential to make sure you’re choosing water-resistant materials for your building envelope. Waster-resistance includes everything from your choice of insulation to the selection of exterior finishes.

As you consider your options for insulating your building’s exterior, you may be wondering—is polyiso insulation water-resistant? 

What is Polyiso Insulation?

Polyiso insulation is a rigid thermal insulation board that is available in multiple thicknesses and panel sizes. The insulating properties come from its closed-cell polyisocyanurate foam core. The foam is bonded to facers, on one or both sides, for protection and to add additional properties. The facers can be made of various materials to meet specific envelope goals.

Common polyiso facers include:

• Aluminum Foil Facer (such as Rmax Thermasheath®)

• Glass Reinforced Facer

• Coated Glass Facer

• OSB or Plywood

Is Polyiso Insulation Water-Resistant?

Depending on your facer selection, polyiso insulation can be water-resistant. The core (polyisocyanurate foam) itself does not absorb water—so if you pick the right facer, the polyiso insulation can be water-resistant. Aluminum-faced polyiso insulation has superior water-resistance properties, and passes ASTM testing with flying colors for water absorption and permeability of water vapor.

Foil-faced polyiso outperforms common polystyrene (EPS) insulations in the water-resistance categories with a water vapor rating of .03 perm and .3% water absorption. These values meet or even exceed those of XPS, a building material that is widely accepted as a water-resistant insulation.

How is Polyisocyanurate Made Water-Resistant?

It’s a common misconception that polyiso-based insulations cannot be used in damp applications. Since the core material (polyisocyanurate) is made of a thermoset plastic, its molecular structure is actually inherently water-resistant. 

It’s the facer that determines whether the overall product is water-resistant. It’s true that paper-based (cellulosic fibers) facers are not waterproof, which means you’ll want to choose an aluminum facer for your polyiso in order to make the insulation product water-resistant for your application.

Foil facers help to shed water away from the insulating core so that the polyiso can function at full thermal capacity. Without any facer, polyiso can become more susceptible to damage, and compromise the material. Rmax Thermasheath® takes advantage of reinforced aluminum foil facers to ensure a water-resistant polyiso product.

Where Can You Use Polyiso Insulation?

Polyiso insulation is versatile. It can be used both above grade and below grade. That means it’s a great product for cavity walls, foundations, exterior walls, and roofs. 

Above Grade Use of Polyiso

Polyiso provides high thermal insulating values per inch. This makes them ideal to use on your building’s envelope without taking up too much space. Using polyiso as your wall insulation can help you minimize your wall thicknesses and reduce material and installation costs. The thinner profile can also help reduce costs by allowing shorter screw lengths in roofing applications, and easier installation.

Foil-faced polyiso is an excellent solution for vertical wall applications since the facer assists with water shedding off of the wall system rather than soaking into it or through it. This is a requirement for cavity walls and other types of backup facades, such as behind rainscreen wall panels.

Below Grade Use of Polyiso Insulation

Since polyiso is water-resistant, it’s an ideal material to use in below grade applications, such as around foundations. Aluminum-faced polyiso can be applied directly against the soil, and its high compressive strengths also make it a suitable material to protect your building’s foundation.

How to Install Polyiso Insulation

Common methods used to install polyiso insulation panels include gluing, screwing, loose-laying, or backfilling. Gluing is common in roofing applications and requires compatibility between the adhesive and the facer. Screwing is common in wall installations and roofing. Loose-laying is acceptable for backfilling against water-resistant foundations or on roofs where the membrane is weighted down with ballast.

Why Choose Polyiso Insulation for Your Building?

Choosing polyiso insulation for your construction projects has many benefits. In addition to its water-resistant properties, numerous applications, and flexible installation methods, polyiso also:

• Reduces the risk of condensation

• Is easily installed in a continuous fashion

• Increases usable building space (when used on the outside of the wall space)

• Eliminates the freeze/thaw cycle from occurring directly against your foundation 

• Is readily available in North America

• Is cost-effective

• Provides high insulating R-value per inch

Choose Rmax Polyiso as Your Go-To Water-Resistant Polyiso Insulation

Figuring out which products to use on your project can be a daunting task. Luckily, some products can be used throughout different parts of your building’s envelope in order to simplify the construction process. Rmax provides water-resistant insulation solutions that work for multiple parts of your project. 

Contact your Rmax representative today to find out which of our products will make your project run smoother while also staying within budget.

Thermal Bridging Explained and How to Prevent it

Energy efficiency must be built into the design phase of a project in order to capture the best numbers. Usually, increased energy efficiency is accomplished by adding continuous insulation to a building’s enclosure (the walls and roof), which helps maintain a constant temperature so that heating and cooling equipment can run efficiently. However, one factor that can throw off your efficiency numbers, if left as an afterthought—is thermal bridging.

What is Thermal Bridging?

Thermal bridging is a phenomenon that can happen when you use materials on the building envelope that have different insulating values. This allows heat to escape through the material with the lower insulating value (higher conductivity), despite it being surrounded by a high-insulating material. 

An example of thermal bridging includes insulation that is secured with screws. The insulation has a high thermal resistance, also known as R-value. Construction screws, which are usually made of metals like galvanized, stainless, or carbon steel, have high conductivity and no thermal resistance. That means that your building’s insulating value can be compromised when insulation is interrupted by metal.

Thermal Bridging in Walls Reduces Energy Efficiency 

Since a building’s walls make up the largest surface area for heat to escape the enclosure, it’s critical to address and reduce thermal bridging in the wall design. In the past, buildings were often insulated only between the wall studs. This creates a major thermal bridging concern since there is a direct and continuous path for heat to escape along the entire height of the building—from the ground up. Thermal bridging in walls must be reduced in order to design more energy-efficient structures and meet energy code requirements.

How to Prevent Thermal Bridging in Walls

By utilizing the right system design, you can significantly reduce the impact of thermal bridging on your building. Using continuous insulation is one of the most effective design methods to prevent thermal bridging in walls. Continuous insulation means that insulation is installed at a constant thickness across the building’s surface without interruption. 

You can take thermal bridging solutions a step further with a few other tactics. Minimize thermal conductivity further in your walls by installing continuous insulation with adhesives rather than screws or channels. Alternatively, if you prefer to loose lay your continuous insulation between supports, there are specialty girts on the market that are made of a non-conductive hardened polyurethane material that can completely eliminate thermal bridging in the wall system.

Polyiso is the Solution to Thermal Bridging 

Selecting the correct type of insulation for your wall system is vital to maximizing your energy efficiency and minimizing your risk of thermal bridging. Rmax polyisocyanurate is the ideal material to use for continuous insulation on walls and roof systems. Here are some of its benefits:

Superior R-Value

Polyisocyanurate has one of the highest R-values (insulating value) of any building insulation type available. That means you can use a thinner and more manageable thickness to reduce material costs, but also achieve a well-insulated envelope at the same time. Rmax Durasheath®, which is a basic polyiso for continuous wall applications, boasts a minimum R-value of 6 per inch of thickness. Rmax ECOMAXci® has an enhanced R-value of 6.5 per inch.

Dimensional Stability

As you install continuous insulation to reduce thermal bridging, you’ll need a material that is stiff enough to hold its own. Unlike fiberglass, which requires paper backing and has no dimensional stability, polyiso is rigid and can be securely attached on the outside of the building structure to form a continuous layer of insulation.

Continuous Surface

Minimize air infiltration and leakage with continuous insulation with sealed joints between pieces. The facers of Rmax’s polyiso insulation are made of a variety of materials (paper, foil, or fiberglass-reinforced), which are all compatible with sealing and flashing tape that is designed to reduce heat loss and air movement at the joints and penetrations. The smooth, continuous surface is ideal as an underlayment for air barrier and cladding. 

All-in-One Underlayment Options

Save time with installation and money on adhesives with Rmax ECOMAXci® Wall Solutions. This all-in-one polyiso air barrier product takes care of continuous insulation, underlayment, and air and vapor barrier for your walls so that they are ready for exterior cladding in a single step. This product features polyiso foam core insulation with heavy-duty aluminum facers for a superior reduction in thermal bridging.

Rmax Polyiso Extends Beyond Thermal Bridging 

Rmax polyiso is a solid choice when designing commercial buildings with high-performance wall assemblies for maximum energy efficiency. The construction industry is constantly improving products to meet advancing building code requirements and to make installation faster and easier for contractors. 

Rmax provides a specialized selection of high-quality building materials to tailor to your project’s specific design needs. Reach out to our experts today to help you find the right Rmax polyiso product for your building.

NFPA 285: Do Your Exterior Walls Pass the Test? Here’s Everything You Need to Know

If you’re a general contractor or architect, do yourself a favor and make sure the exterior walls of your project comply with NFPA 285 long before the building inspector shows up on site.

Given the daunting title of “Standard Fire Test Method for Evaluation of Fire Propagation Characteristics of Exterior Wall Assemblies Containing Combustible Components,” NFPA 285 is simply a test that analyzes how fire spreads on different non-combustible exterior wall assemblies that contain a combustible component.

Why Was the NFPA 285 Test Created?

The National Fire Protection Association (NFPA), a global nonprofit organization dedicated to increasing public safety, conducts research and testing to create fire safety standards for many industries, including construction. Like NFPA 285, many of NFPA’s standards are adopted by the IBC (International Building Code) and become building code requirements.

NFPA released its first edition of NFPA 285 in 1998. However, testing of flammability in exterior walls began in the late 1970’s due to increased interest in foam plastic insulation amid rising environmental concerns. By that point, foam plastic had been around for a while – it was developed by the U.S. military in the early 1940’s – but its use in residential and commercial construction had just begun.

Spurred on by foam plastic’s increasing popularity for use in construction, the Society of the Plastics Industry (SPI) began testing the use of foam plastic insulation in exterior walls for fire safety in the early 1980’s. SPI’s work led to the adoption of UBC 17-6, the first iteration of what would eventually become NFPA 285.

When is NFPA 285 Compliance Required?

The requirement to comply with the NFPA 285 test is found in IBC 2603.5.5 Foam Plastic Insulation which states: “Exterior walls containing foam plastic insulation in buildings of Type I, II, III or IV construction of any height must comply with NFPA 285.”

It is important to note that NFPA 285 is a test for exterior wall assemblies, not individual components of the wall. There are two exceptions to IBC 2603.5.5, but they are quite narrow. The majority of construction projects that call for foam plastic insulation will need to specify NFPA 285 tested wall assemblies for exterior walls.

If your exterior wall details deviate from NFPA 285 tested assemblies, they are not in strict compliance. In that case, an engineering judgment would be necessary to approve the modified NFPA 285 assembly, or a test of the proposed assembly would be required.

At this point, you might be wondering how the NFPA 285 test is conducted and what the criteria is for compliance. During NFPA 285 testing, a 2-story mockup of an exterior wall is built according to the assembly to be tested, then set on fire for 30 minutes.

In order for the exterior wall assembly to meet the test’s criteria, the horizontal and lateral flame propagation cannot spread beyond specified limits. In addition, the temperature within exterior wall panels, and within the air cavity between walls panels and the wall itself, cannot exceed specified limits. For more information, including additional criteria not described here, see Section 10.2 of the 2019 edition of NFPA 285.

The Benefits of Foam Plastic Insulation in Exterior Walls

From its military roots in the 1940’s, foam plastic insulation has evolved into a sophisticated rigid insulation material used in a wide variety of construction applications that offers many benefits, including:

High R-Values

Rigid foam plastic insulation’s high R-value per inch of thickness means it is extremely efficient and effective compared to other types of insulation.

Prevents Air Leakage

Rigid insulation provides a continuous seal around the building which keeps indoor air from escaping and outdoor air from entering.

Prevents Thermal Bridging

Thermal bridging occurs when air is allowed to pass through a conductive building material (like a stud) without being blocked by insulation, which causes heat loss. Continuous rigid insulation prevents this from happening.

Moisture Control

Continuous rigid insulation protects wall components and interior sheathing from the damaging effects of moisture.

Energy Efficiency

By providing a continuous seal that prevents air leakage and thermal bridging, rigid foam plastic insulation helps regulate indoor air temperature, which means buildings use less energy for heating and cooling.

For these benefits and more, rigid plastic foam insulation is an excellent choice for your project. As a leading manufacturer of polyiso insulation boards for over 35 years, Rmax has developed solutions for a wide range of construction applications, including NFPA 285-compliant exterior walls.

Rmax Polyiso Rigid Insulation Boards - The Superior Choice for NFPA 285-Compliant Exterior Walls

When it comes to NFPA 285-compliance, Rmax has solutions. Their polyiso insulation boards provide superior energy-efficiency, thermal performance, and durability. Rmax TSX-8510®, Durasheath®, Thermosheath®, and EVOMAXci® rigid insulation boards all passed the stringent NFPA 285 test.

A variety of NFPA 285-compliant assembly configurations are possible using TSX-8510®, Durasheath®, and Thermosheath®. Assembly guides are available at www.rmax.com to assist you in the design of your exterior wall assemblies.

EVOMAXci® is intended for use in conjunction with the innovative EVO™ Architectural Panel System.

Rmax TSX-8510: Continuous Insulation for Exposed Interior Use

Rmax TSX-8510 is designed to be exposed on the interior with an attractive and durable white modified acrylic coating on the exposed face. TSX-8510 is an energy-efficient thermal insulation board composed of a closed-cell polyiso foam core bonded to glass fiber reinforced aluminum facers on both sides.

Construction Applications

• Pre-engineered metal buildings

• Tilt-up construction

• Wood stud basement & crawl spaces

• Farm or storage buildings

• Parking structures

• Laminate panels and other similar applications 

Rmax Durasheath®: Building Envelope Insulation 

Rmax Durasheath® is intended for use in exterior walls with stucco veneer, concrete sandwich panels and many other building envelope applications. Its non-metallic, inorganic polymer-coated glass fiber mat facers make it the perfect choice when a permeable faced product is preferred.

Exterior Wall Applications

• Stud walls

• Cavity walls

• Masonry walls

• Exterior stucco

Rmax Thermasheath®: Insulation for The Envelope

Rmax Thermasheath® is a lightweight thermal insulation board with reinforced aluminum foil facers that protect against water, air, vapor, and UV. 

Exterior Wall Applications

• Exterior Walls (Type I-IV):

• Masonry

• Steel Stud

•  FRTW Stud

•  Wood Stud (Type V)

•  Below-grade exterior walls

EVOMAXci®

Continuous Insulation for use with the EVO™ Architectural Panel System

The innovative EVO™ Architectural Panel System is the product of a partnership between Rmax, EVO™ Architectural Panel System and Larson® by Alucoil®. The wall system components are:

• ECOMAXci® FR Air Barrier thermal insulation board

• Rmax R-SEAL 3000 tape and R-SEAL 6000 flashing

• Larson® Aluminum Composite Panels (ACM)

• EVO™ Architectural Panel by Carter

What ECOMAXci® by Rmax brings to the EVO system is its first line of defense: an air barrier and continuous insulation with enhanced R-values and zero infiltration. It has glass fiber-reinforced aluminum foil facers on both sides, to provide superior durability, dimensional stability, and fire performance.

Choose Rmax Superior Rigid Polyiso Insulation Foam Boards for Your NFPA-Compliant Exterior Walls 

Rmax has been providing exceptional insulation products for over 35 years. Built on decades of rigorous scientific research and testing, Rmax polyiso insulation boards are second-to-none in efficiency, effectiveness, and durability. If you need help with an NFPA 285-compliant assembly for your project, or would like more information about Rmax products, reach out to our team today. 

The Best Insulation for Concrete Block Walls

When the big bad wolf comes knocking at your door, which building material will you have wished you had chosen? Concrete and masonry are two materials that come to mind as indestructible, even for this notorious storytime character. 

In all seriousness, if you’re looking to build a strong structure that will last a lifetime, concrete masonry units (CMUs)—commonly called concrete blocks or cinder blocks, are the solution. If you’ve chosen CMU for your walls, there are some things to know about the building material and how to properly insulate this wall type.

Concrete Block Wall Basics

A concrete block is basically what it sounds like. It’s a building material made out of concrete that is shaped like a building block. In typical concrete block wall construction, concrete blocks are stacked on top of each other like bricks and held together with mortar. Sizes and shapes can vary, but these units typically come in dimensions of 8” wide by 16” long by 8” height.

Where to Use Block Walls

Concrete block walls are versatile and are used both above and below-grade. Common examples of commercial buildings that are often constructed with CMU walls include grocery stores, schools, and prisons. Below-grade applications are common for residential foundations that form the walls for crawl spaces, and sometimes basements. 

There are many benefits to choosing concrete block walls for your project. A few advantages include the following:

• Naturally fireproof

• Less susceptible to mold, moisture, and pest damage

• Wind-resistance

• Heavy load-bearing capacity

• Inexpensive

• Exceptional security

Block Wall Section Materials

Most times, concrete block walls are made up of more than just a stack of concrete masonry units held together with mortar. For example, a brick cavity wall uses brick veneer attached to structural block. Alternatively, metal wall panels, siding, and other materials can be attached to a backup block wall for a premium finish. A functional CMU wall section often includes a range of components, including:

• Insulation

• Air space

• Moisture barrier

• Waterproofing (below grade)

• Brick veneer

• Reinforcement

• Flashing

• Interior finishes

• Exterior finishes

Insulation Techniques for Block Walls

If you’ve chosen concrete block walls for your project, the next step is to consider which components will make up your wall section. Specifically—when choosing materials, you’ll need to decide which type of insulation to use for your block wall. Additionally, you’ll need to select a compatible installation method. 

Insulation can be installed inside the CMU block wall, on the exterior side of the block, or on the interior side of the wall. Some contractors choose spray foam, blow-in, or injection-type insulations for concrete block walls. These methods can be messy and cause problems if you need to cut through the wall at a later date. An alternative solution to increase the insulation value of your concrete block walls is a rigid insulation, like polyiso.

Polyiso insulation boards typically come in modular sizes, such as 4’ x 8’, and are easy to cut with a utility knife. They install quickly with versatile installation techniques, including:

• Screws and plates

• Adhesives

• Loose-laid into metal channel or girt supports

• Backfilling

Rmax Polyiso for Block Wall Insulation

Insulation is a critical component that is often added to concrete block walls to increase the wall system’s overall insulating value. The insulating R-value for polyiso packs the most punch with R6 per inch—meaning that you can achieve R13.1 with a single 2” thick layer (the facer adds to the R-value).

These Rmax polyiso products are for block wall exterior installations:

• Rmax ECOMAXci® FR is a polyiso with aluminum facers used in block wall insulation exterior

• Rmax ECOMAXci® FR Ply is a polyiso bonded to fire-retardant treated plywood for a nailable surface 

When insulating the interior cavity of a concrete block/brick veneer wall, foil facers are not always necessary. Polyiso provides a high insulating value per inch for this tight space.

• Rmax Durasheath® is a polyiso with inorganic polymer-coated glass fiber mat facers for cavity walls and foundation applications

You can also use polyiso insulation for concrete block basement walls to protect waterproofing during backfilling.

• Rmax Thermasheath® is a polyiso that is compatible with backfilling and used in many construction applications, including as exterior insulation of concrete block walls

Click here to browse all of our insulation offerings by application or installation method.

Let Rmax Help Pick the Best Insulation for Your Block Walls 

Stuck or overwhelmed trying to decide which insulation to use for block walls in your project? Reach out to your Rmax representative today to get expert advice on which insulation solution will complement your design the best. We have a selection of high-quality polyiso products that are specifically designed to meet building code requirements, simplify installation, reduce costs, and accelerate the construction phase of your project’s envelope.