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.

Building Code Insulation Requirements in Texas

Building codes are the rules that everyone involved in construction—from architects and contractors to building owners—are legally obligated to follow. They are set at the local level, but national and global guidelines are also adopted as models. 

This set of rules covers everything from how tall your building can be to which way your doors must open. Understanding building code requirements is critical because it can affect everything about your building’s design. For instance, insulating R-value (thermal resistance) requirements in your building’s envelope will determine the thickness of your walls. This impacts which materials you’ll select to meet the code requirement and fit with your design intent.

It can be challenging to stay informed on new and changing building codes. So, before you begin building that new home or commercial structure in Texas, you’ve got to know the laws. This article helps you do that by sharing the need-to-know on building code insulation requirements in Texas.

Reviewing Codes Before You Build in Texas 

Building codes must be reviewed—before permitting, procurement, or picking up a hammer. It’s during the design phase that building codes should first be taken into account. Codes can vary based on your geographical location, so every building may have different requirements. For the purpose of this article, we will focus on the larger geographical regions inside Texas. However, you will need to consult your local government (city or county) about local building codes for your area.

The International Code Council (ICC) sets performance standards for building envelope energy efficiency. The ICC created the IECC (International Energy Conservation Code) to set the standard for building codes related to energy efficiency for residential and commercial structures. This code contains zoning maps that divide the U.S. into different climate zones based on temperature, humidity, and rainfall. Texas is currently operating under the 2015 IECC for both residential and commercial, effective since 2016. 

Inside Texas, there are three climate zones, according to the IECC Climate Zone Map. They include:

• Zone 2: Southern Texas

• Zone 3: Central Texas

• Zone 4: Northwest Texas

In 2021, a new map was released that added additional climate zones. Once adopted, Texas climate zones will include:

• 1A: Southern Tip of Texas—Very hot and humid

• 2A: Southeast Texas—Hot and humid

• 2B: Southwest Texas—Hot and dry (humid below the line)

• 3A: Northeast Texas—Mixed and humid

• 3B: West Texas—Hot and dry

• 4B: Northwest Texas—Mixed dry

Once you have identified the climate zone that your building will be located inside, you can find out which insulation code requirements apply to your Texas building.

Residential Insulation Code Requirements in Texas

According to EnergyStar.gov, insulation code requirements for Texas homes depend on the geographical region the building is located in. Here’s a look at the different zones and R-value (insulating value) requirements for residential buildings:

The International Residential Code (IRC) also sets standards for energy efficiency for single and dual-family homes up to three stories above-grade. It currently requires R30 to R38 in attics and ceilings, R-10 to R-15 in basement walls, and R-13 up to R-25 for floors and walls, depending on your zone.

Texas Commercial Building Insulation Code Requirements

For commercial buildings, the current building envelope R-value requirements per IECC 2015 by zone are below:

Products that Meet Texas Building Code Requirements 

Once you’ve confirmed your insulation requirements at the local level, it’s time to look for the right insulation product for your project. Rmax stays current on building codes and carries code-compliant insulation so that contractors have one less thing to worry about when it comes to adhering to codes. 

When Rmax products are installed as directed, they meet or exceed code requirements. 

To help envision your design and build with the right materials, try out this wall calculator tool. Enter the details such as—code designation, zone location, and insulation values to preview your wall section and make sure it passes energy codes. 

Each Rmax product has passed a series of rigorous tests. Find out which codes and tests each product has passed by visiting the product page. Here are a few Rmax polyiso insulations that are compatible with Texas building code requirements and carry an impressive R-value of 6 per inch:

• Durasheath® for walls 

• ECOMAXci® FR for walls and ceiling 

• Thermasheath® for walls and ceiling

Rmax Experts Can Help You Pick the Right Polyiso Insulation

Failing to meet building codes can slow down your project before it hits the ground running. Take the time now, during the design phase—to make sure you’ve got it right before you apply for a permit.

If you’re in the process of selecting the right building materials to meet code requirements in Texas, reach out to your designated Rmax representative today, who can help you choose the right code-compliant insulation for your design.

Closed Cell Foam Insulation vs. Alternatives: What Sets it Apart?

Deciding on the proper insulation for your project can take time given the many different types readily available on the market. While many kinds may be available, they often perform in very different ways and some are much better suited for certain applications than others. Knowing the key differences is the first step to selecting the right type of insulation for your application.

Open Cell vs. Closed Cell Foams

Foams are broadly classified by the structure of the cells in the foam, either open or closed. Whether or not more than half of a foam’s cells are open or closed has a tremendous impact on many of the foam’s properties and whether or not it is classified as an open or closed cell foam.

Open Cell Foams

Similar to rubber, open cell foams are combined with an inflating agent during the manufacturing process. The agent expands as the foam hardens or vulcanizes. Some of the most common open cell foams are:

• Reticulated foam

• Polyurethane foam

• Open cell rubber

Many open cell foams have a soft, springy appearance and will quickly return to their original shapes after being deformed. These flexible foams make for great sealing applications and are often found in insulation, sound and shock absorption, and upholstery.

Closed Cell Foams

The cells in a closed cell foam are completely enclosed and do not interconnect with other cells. Typically manufactured with blowing agents, closed cell foams are often stronger and more resilient than open cell foams. Common closed cell foams include:

• EPDM

• Neoprene

• EPS

• XPS

• Polyiso

The trapped bubbles of gas in the foam give closed cell foams excellent insulation properties. The closed nature of the cells also decreases water’s ability to permeate the foam.

Closed Cell Insulation Performance

The tight-packed nature of the cells in closed cell foam insulation tends to give these types of foam a higher R-value per inch than open cell insulation types. In addition to being better insulators, closed cell foams tend to be denser and structurally stronger. Dimensional stability and resistance to water, mildew, and chemicals are all also higher in closed cell foams.

Closed Cell Insulation Installation

The dimensional stability of closed cell foams and the lightweight nature of the foam board makes them easy to install on job sites. The resilience of closed cell foam gives it the versatility to work in cavity insulation or in an exterior insulation application.

Cavity Insulation

After the framing members are installed and exterior sheathing has been secured, closed cell foam can be installed in the cavities between the framing studs. Closed cell foam is strong but can be easily cut so that it can be trimmed to the right size just before installation. 

Adhesive can be applied to the face of the foam board or closed-cell spray foam can be applied to the perimeter of the wall cavity. The closed cell foam board is then pressed into the cavity and sealed tight against the exterior sheathing. Spray foam or tape can be used to seal any seams between panels of foam board.

Continuous Insulation

While often used in interior cavity insulation applications, closed cell foam is uniquely suited for performance as an exterior or continuous insulation. After the framing members have been erected and exterior sheathing applied, closed cell foam boards are installed on the outside of the sheathing.

Fasteners are used to penetrate through the closed cell foam boards and into the framing members. A few fasteners are used for each board to keep the boards tightly in place. Once all the foam boards have been fastened, tape is used to seal the gaps between the insulation panels.

Rmax Polyiso: The Closed Cell Foam of Choice

Closed cell foams bring exceptional thermal performance, structural rigidity, and resistance to moisture, however, not all closed cell foams are created equal. Rmax polyiso exceeds other closed cell foams, like EPS and XPS, in R-value per inch performance. Polyiso also has a more tightly packed cell network to enhance many of the properties of closed cell foams like moisture resistance.

One of the properties that truly sets Rmax polyiso apart from XPS and EPS is its high-temperature performance. Polyiso, a thermoset, performs very differently from XPS and EPS, both thermoplastics, when exposed to elevated temperatures. While polyiso chars and hardens, XPS and EPS both soften and melt as the temperature increases.

When installed in a continuous insulation application, the surface temperature of the insulation can reach surprisingly high temperatures. Under these conditions, XPS and EPS may not stay installed in the same condition as the day they were installed. Shifting of the insulation means the building may not perform as well over time.

When choosing a closed cell foam, the performance of Rmax polyiso makes the decision easy. For a closed cell foam that will perform exceptionally throughout the life of the building, choose Rmax polyiso. 
Reach out to our team of closed cell foam experts today to learn more about why polyiso should be your closed cell foam of choice!

XPS Foam Insulation: Applications, Performance, and a Great Alternative

One of the most popular types of foam insulation on the market, XPS is used in many different construction applications. Knowing XPS’s strengths and weaknesses make it much clearer on when to use it versus another type of insulation. Learn more about what XPS is, how and when to use it, and when other insulation types make more sense.

What is Extruded Polystyrene (XPS)?

Extruded polystyrene is made through an extrusion process into a rigid foam board. Blowing agents are injected into a mix of molten polystyrene before being forced through an extruder. The mix of the blowing agents and injection pressure pushing the molten mix through the extrusion die results in a foam board with tight cell spacing.

Easily recognizable by its blue, green, or pink color, XPS can be found on many job sites. This type of foam board readily accepts being faced and can be sold unfaced as a semipermeable rigid insulation board. 

XPS is a closed cell foam with an R-value of around 5 per inch of thickness and is very lightweight and durable. The tight cell spacing and closed cell nature of XPS make it an excellent vapor retarder due to its low permeability, especially when faced. XPS panels also provide a great deal of compression strength and dimensional stability. During the extrusion process fire retardants can be mixed in to improve fire-resistance. XPS can even be recycled.

How is XPS Installed?

XPS panels are used in a variety of different applications, and the structural characteristics of the panels make them fairly easy to install.

Cavity Insulation

For a cavity installation, XPS panels are fairly easy to work with. XPS panels can be scored and snapped or cut with a table saw to fit the size of the wall cavity. Spray foam is typically applied along the perimeter of the cavity. Instead of spray foam, XPS compatible adhesive can be applied to the face of the panel that will go against the exterior sheathing. The cut XPS panels can then be pushed into the cavity and sealed with the spray foam.

Exterior Insulation

XPS is often installed as exterior insulation as well, especially below grade. After initial framing of the wall’s structural components, XPS panels are installed directly on the exterior of the framing members. Typically, ⅜” head galvanized nails, 1” crown galvanized staples, or equivalent fasteners long enough to penetrate at least ¾” into the framing members are used to secure the insulation. 

The XPS panels are secured to the framing members using a few fasteners per board. Fasteners should not be over-driven to ensure long term stability of the installation. After the panels are secured, tape is used to seal all of the insulation joints.

How Much Does XPS Cost?

XPS tends to be slightly more expensive than EPS and a bit cheaper than polyiso foam boards. While material prices can be highly volatile, XPS typically costs around $0.42 per square foot for one inch thick panels. XPS is often used in applications with tougher requirements that EPS cannot meet. Even for general insulation purposes, XPS can still be a viable alternative due to the ease of working with the material.

Best Applications for XPS

XPS is a strong and durable foam board with respectable thermal properties. This type of foam board typically works well in applications requiring higher strength and exposure to moisture. Common applications for XPS include:

• Cold storage floors

• Basement and below grade insulation

• Under slab insulation

• Flat roof insulation

• Parking decks

The compressive strength of XPS and stability over time make it a great choice for underfloor insulation. For the same reasons, XPS is often selected for insulating foundation walls.

Rmax Polyiso: The Better Choice for Continuous Insulation

XPS is a great choice for insulation, and when it comes to continuous insulation applications polyiso is also the clear winner. Continuous insulation requirements are increasing and architects, designers, and specifiers must choose which type of insulation to use for their projects. Polyiso is not only a better insulator than XPS, but is also a completely different material.

Polyiso is a thermoset while XPS is a thermoplastic. The difference between these two materials can easily be seen at elevated temperatures. XPS, being a thermoplastic, softens and melts into a liquid when heated. Polyiso, however, chars and hardens. 

Due to the elevated surface temperatures of exterior walls, over time XPS may not stay in place in the same way polyiso will. The elevated temperature performance coupled with the dimensional stability, moisture resistance, and superior thermal performance of polyiso make the choice easy. 

For a continuous insulation material that will perform as well decades later as the day it was installed, choose Rmax polyiso! Contact our experts today to find the perfect solution for your project.

How to Best Protect Foundation Walls: The Most Effective Systems

Any building materials in contact with the ground must be properly rated and designed for ground contact. Termites, water damage, and other factors can cause deterioration over time and lead to serious damage. Choosing effective systems for protecting your foundation walls saves you money and headaches while making your walls stronger and longer lasting.

Why is Protection Necessary?

Critters and nature can wreak havoc on materials in contact with the ground. Carpenter ants, termites, and other insects will nest in anything they can find, including many types of building materials. Pests and rodents will take advantage of routes into the wall if they can find or make them. Water is also a concern any time building materials have ground contact. Water can cause deterioration and rot over time and can be sucked into the wall due to capillary forces.

The Most Effective Protection for Foundation Walls

Many systems and methods exist for protecting foundation walls. Choosing the best for your home depends on your specific situation. Some of the most effective methods are listed below:

Clearance to Grade

The International Residential Code (IRC) recommends a 6-inch distance between grade and any untreated wood. Some states go further and require 8 inches, so it’s important to check your local building codes. Prevent mulch, pavers, plants, or other features that raise the grade from getting too close to your home’s foundation walls. Keeping water away from your home’s foundation walls is critical to keeping your walls healthy. When relying on clearance to grade as your main form of protection, maintenance is key.

External Protection

Adding an external coating can help give your home’s foundation walls an extra layer of protection. Most approaches involve applying a stucco-like finish with a surface-bonding cement. Some of these finishes are thin enough to be painted on while others are similar to a thick acrylic-modified mortar. Hardware cloth or fiberglass lath is sometimes used as a back layer to give the protective surface more strength. These surfaces work as long as the surface stays in good condition, but unfortunately these types of protective surfaces can be prone to chipping and must be repaired regularly.

Water Routing

Keeping water away from the foundation is critical for the health of the foundation’s walls. Make sure that water will properly shed away from the home and can drain easily. Gutters are a great way to control and route the flow of water away from the home. Gutters should flow into downspouts which direct water at least ten feet away from the home’s foundation.

Waterproofing Membranes

Waterproofing membranes work by giving waterproof characteristics to materials that typically cannot stand up to much water exposure. Available as spray-on, brush-on, or roll-on types of membranes, they are typically applied during construction. Once buried, the membrane protects the wall from moisture. These systems can work well when properly applied, but leave a great deal of room for human error.

Dimple Mats and Drain Boards

Part of the issue with waterproofing below grade walls can be moving the water that does get in, away from the walls. Typically made from high-density polyethylene sheets with dimples along the surface, the dimple sheet is installed so the dimples face the foundation wall. The dimples create an air gap between the sheet and the foundation wall. Any water that gets through the membrane is then able to drain away from the wall.

Below Grade Safe Materials

While most organic materials will not do well below grade for the long-term, some products work just fine. Closed cell foams like those used in Rmax polyiso foam boards resist water absorption and are of no interest to insects and other pests. Additionally, polyiso boards resist compression from soil loads while retaining exceptional thermal performances. The other benefit of using polyiso on a below grade wall is the added insulation benefits that keep the walls warm and reduce the potential for condensation on the inside surface of the wall.

Rmax Polyiso: The Superior Solution

Rmax polyiso insulation boards are built to withstand the challenges faced by below grade foundation walls. Backed with a water shedding facer, Rmax polyiso properly sheds water keeping the foundation walls safe and in good condition. Combined with the other mentioned best practices, Rmax polyiso is hard to beat!

To learn more about Rmax polyiso’s exceptional below grade performance, reach out to our insulation experts today.

California Building Code Insulation Requirements

When it comes to building codes across the nation, California’s Title 24 can be some of the most thorough. Understanding California’s building codes is key to an efficient construction project that will be fully code-compliant and will pass inspection and commissioning. Learn more about California’s building code requirements for insulation so you will be prepared.

What is Title 24?

Most discussions concerning the California building code start by mentioning Title 24. Used as the basis for construction in California, the California Title 24 Building Energy Efficiency Standards are designed to ensure new and existing buildings achieve energy efficiency and preserve outdoor and indoor environmental quality. Title 24 applies to the construction of, additions and alterations to, residential and nonresidential buildings except for jails and prisons. This progressive set of building codes and standards often leads the nation in requirements for energy efficiency.

How Did Title 24 Start?

The Warren-Alquist Act established the California Energy Commission (CEC) in 1974, which ultimately developed and adopted the energy efficiency standards that became Title 24. The codes are updated over time, typically every three years, to incorporate new energy efficiency technologies and construction methods. 

Title 24 Requirements

Almost all construction in California must adhere to the requirements laid out in Title 24. A lack of knowledge of the standards does not qualify as an excuse for not adhering to them and will result in delays and increased costs on construction projects. Certain requirements or measures within Title 24 are either mandatory or prescriptive.

Mandatory Requirements

These requirements must always be met for a construction project. They can not be traded off. These requirements set the baseline for construction in the state of California.

Prescriptive Requirements

The predefined efficiency requirements may supersede mandatory requirements. The requirements can be different for new construction, additions, and alterations. Prescriptive requirements allow for more flexibility.

Two Paths for Compliance

Seeking compliance under Title 24 offers two common approaches: the prescriptive approach and the performance approach.

Prescriptive Approach

Most common for alterations and non-residential construction projects, this approach is very simple. The prescriptive approach allows for no trade-offs. The construction project must match the standard building baseline.

Performance Approach

A much more flexible approach, the performance approach does allow for trade-offs. All mandatory requirements must still be met and CEC-approved software must be used in the design process. Homes and buildings designed under the performance approach must have lower energy design ratings than the standard building design, meaning they must be more energy efficient than the standard building.

Title 24 and Insulation

Insulation plays an important role in Title 24 due to the impact insulation has on an overall building’s energy efficiency. Title 24 sets the minimum amounts of insulation in terms of U-factor. The U-factor is a measure of the heat transmission through a given thickness of material. The U-factor is simply the inverse of the R-value (1/R).

Mandatory Requirements for Insulation

All insulation must be certified to California Quality Standards for Insulation Materials by the California Department of Consumer Affairs. Certain insulation materials are not allowed in California that are allowed in other parts of the U.S. Foam insulation made from formaldehyde is restricted under Title 24. Fire retardants must all be exposed on surfaces and installed according to code.

Roof and Ceiling Insulation

Title 24 requires that insulation be placed in direct contact with the infiltration barrier. If using a ventilated attic design, this makes the ceiling drywall the infiltration barrier. 

When insulation is at the roof, no openings or vents into the unconditioned space are allowed between the ceiling and roof. The maximum U-factors listed in Title 24 for roof and ceiling assemblies are:

• Roof and ceiling - metal building: 0.098

• Roof and ceiling - wood framed and other: 0.075

Wall Insulation

The insulation requirements for wall assemblies are included in Title 24 as well. The maximum U-factors allowed for walls under the mandatory requirements are:

• Walls - metal buildings - 0.113

• Walls - metal-framed walls - 0.151

• Walls - heavy mass walls - 0.690

• Walls - light mass walls - 0.440

• Walls - wood-framed walls and other - 0.110

Rmax’s Polyiso Insulation and Title 24

When building in California, using the right products makes achieving compliance a much simpler process. Products like the Rmax Durasheath® building envelope insulation are not only compliant under the California Code of Regulations, but also provide sufficient R-values to satisfy Title 24. Rmax polyiso products are designed as easy to work with rigid foam boards.

Other Rmax products that comply with the California Code of Regulations include:

• Rmax ECOMAXci® 

• Rmax ECOMAXci® FR Air Barrier 

• Rmax ECOMAXci® Ply 

• EVOMAXci

• Rmax® Pro Select Polyiso

• Rmax ThermaBase-CI™

• Rmax Thermasheath®

• Rmax Thermasheath®-SI

• Rmax TSP®

• Rmax TSX-8510

To learn more about why Rmax polyiso products should be your first choice when building in California, reach out to their team of specialists today!

The Best Insulation for Exterior Walls

Insulation in commercial exterior walls is key to a building's energy efficiency, longevity, and comfort. Choosing the right type of insulation can save money and result in a better overall building. Keep reading to learn more about the best types of insulation for commercial exterior walls. 

The Importance of Insulation

Insulation has a multitude of benefits for a building including higher energy efficiency. While proper insulation reduces a building’s heating and cooling loads (and therefore the energy bill), insulation also makes a building more durable and occupants happier.

Building Reliability

Proper insulation installation results in a wall structure with little leakage and low thermal conductivity. Inferior insulation not only wastes energy but can reduce the reliability of the entire wall assembly. 

Condensation can form inside the wall of exterior commercial walls with insufficient or improperly installed insulation. This condensation can lead to rot or deterioration that reduces the life of the building and can be costly to repair. This damage is often hard to detect too, making repairs more expensive when the problem is finally discovered.

Well-installed insulation also helps to keep critters and pests out. When wall assemblies are properly installed with insulation, it is much harder for pests to make their way through holes and openings into the building. Pests in walls can do as much or more damage than condensation.

Occupant Comfort 

Keeping a building's occupants comfortable is key to keeping them happy and productive. Insulation not only reduces the amount of energy a building uses to control the temperature, but also keeps the temperature consistent throughout the building. Reducing hot and cold spots makes the entire building more pleasant to occupy and reduces the load on the building’s HVAC system. 

Another benefit of commercial exterior insulation is the reduction in noise. External noise has a harder time passing through exterior walls with Insulation. Sounds from inside the building are also dampened due to the insulation.

Energy Efficiency

The primary reason for insulation in commercial exterior walls is to reduce the amount of energy a building consumes. Keeping the interior of a building at a different temperature than the outside requires energy to move that heat around. Without insulation, the heat will flow right back into or out of the building. Insulation helps to slow this flow of heat and reduce the amount of energy the HVAC system consumes.

What Are the Most Common Types of Insulation?

Many different types of insulation are available on the market. Choosing the right insulation for a commercial exterior wall depends on price, desired performance, and the type of building where the insulation will be used. Some of the most common types of insulation are:

Spray Foam

Different from many of the other types of insulation available, spray foam uses specialized equipment to spray a layer of high-performance foam directly onto the building’s interior surfaces. The foam is very sticky and expands on contact with the walls and roof surfaces. As the foam expands and hardens, a high R-value foam is left behind. The foam is waterproof, mold-resistant, and great at filling air gaps as it expands and hardens.

Fiberglass Board

One of the most popular options for commercial buildings, fiberglass boards are made by stacking together many layers of fiberglass and compressing them into a board shape. These boards are installed in wall cavities and provide a decent level of thermal performance.

Fiberglass Blanket

Instead of coming as a rigid board, fiberglass is also available in blanket or batt insulation. Often sandwiched between pieces of cardboard, the blanket is made from many layers of fiberglass. The fiberglass does not provide much structural support, so installation can be more difficult, but it is a very economical choice. Because fiberglass blankets tend to droop, one potential concern is that over time the blankets will shift and the R-value of the building’s walls will decrease over time.

Rock Wool

Made from high-density mineral wool, rock wool insulation is routinely used to insulate small spaces and high-temperature pipes. Rock wool is often added to boost insulation in certain areas. Another benefit of rock wool is that it helps to dampen sounds acoustically, and makes spaces more enjoyable to occupy.

Loose-Fill Insulation

For covering a large area with insulation in a short amount of time, blown-in or loose-fill insulation is hard to beat. Specialized equipment is used to blow the insulation into the space. The insulation is made from cellulose or fiberglass and can cover hard-to-reach areas quickly and effectively.

Rmax Polyiso, the Superior Choice

While many of the insulation types discussed have unique features, Rmax polyiso is an industry leader for a reason. Rmax polyiso boasts an impressive R-value per inch over 6, meaning less insulation is needed for a commercial building to hit the required R-value. Rmax polyiso is strong, lightweight, and easy to use making it an easy choice for commercial exterior walls. 

To learn more about Rmax polyiso, reach out to our team today.

Can Polyiso be Used for Exterior Wall Insulation Boards?

For more than 35 years, Rmax has been creating insulation solutions based on the latest building science. Our full line of high-quality, polyiso-based wall and specialty insulation products for commercial, residential, and industrial applications deliver maximum R-values and minimum environmental impact with efficiency in installation, cost, and design.

Rmax insulation has been designed and tested to provide building envelopes with superior insulating protection while meeting the newest codes and requirements. Rmax products are leaders in both performance and environmental sustainability. Rmax offers polyiso products to meet the needs of any application.

Rmax’s engineered products and solutions allow for ultimate efficiency through multiple design options, ease of construction, and reduced energy usage. This leads to a better building envelope while adding to the bottom-line through both material and labor savings - making Rmax an excellent choice for commercial and residential applications. Whatever the application, Rmax is there to deliver performance and quality!

Leaders in Continuous Insulation

Continuous insulation (CI), as defined by ASHRAE 90.1, is:

“Insulation that is uncompressed and continuous across all structural members without thermal bridges other than fasteners and service openings. It is installed on the interior, exterior, or is integral to any opaque surface of the building envelope.”

Instead of cavity insulation that fills the voids between studs, continuous insulation wraps the exterior of a building in a continuous layer of insulation that covers any “holes” where heat could have otherwise leaked through the building envelope.

Increased desires for energy efficiency and overall better building practices have pushed standards to require CI in more applications. Rmax polyiso can meet the increased material requirements needed in a continuous insulation product. High dimensional stability, resistance to chemicals and mold, and facers that provide built-in air and vapor barriers are just some of the features that make Rmax polyiso exceptional. As leaders in creating insulation based solutions, Rmax is on the forefront of delivering insulation to meet new and varied needs.

Polyiso’s Evolution

Once a product used almost exclusively in wall construction, polyiso has evolved into a product with attributes that allow it to be applied to a variety of different applications.

Originally made using ozone depleting blowing agents, polyiso has continued to evolve and improve in both performance and environmental sustainability. Now produced with a high percentage of recycled materials, Rmax polyiso is a green solution for building projects.

Polyiso is not just a green solution during manufacturing. The benefits continue for the life of the insulation. Because of polyiso’s incredible thermal performance, Rmax polyiso reduces the energy consumption of buildings where it is used for the life of the building. This decrease in energy usage is just another part of polyiso’s green lifecycle.

Fire and Water

Part of what makes Rmax polyiso special is the characteristics the insulation panels have outside of their thermal performance. Rmax polyiso can take on both water and fire. With properly treated joints, polyiso panels can function as a water-resistive barrier that results in labor savings and a tighter building envelope. Polyiso can withstand moisture exposure without being damaged or losing its performance characteristics which sets it apart from many other insulation types.

An interesting phenomenon occurs when Rmax polyiso is exposed to fire. Instead of melting like other insulation types, Rmax polyiso chars and hardens. Unlike other insulation types, Rmax polyiso does not require a tradeoff between energy efficiency and building safety. With Rmax polyiso, you get the best of both worlds.

The Rmax Polyiso Advantage

When used in wall assemblies, polyiso brings great advantages to building construction. With great strength and dimensional stability, Rmax polyiso is easy to work with and installation is a breeze. Built-in facers also allow Rmax polyiso to be easily tailored to the application where it is being used.

Common construction applications for Rmax polyiso include:

• Stud walls

• Cavity walls

• Masonry walls

• Exterior stucco

• Re-siding

• Vaulted-ceilings

• Attics and crawl spaces

• Limited roofing

With all of the certifications and ratings that come with Rmax polyiso, you can rest assured that the polyiso will be up to the test no matter how it is used.

Some compliances of Rmax polyiso:

• ASTM C1289 Type II, Class 2

• ASHRAE 90.1

• International Building Code (IBC) Section 2603, Foam Plastic

• DrJ 2202-02

• California Code of Regulations, Title 24 (BHFTI License T1523)

• Tested per NFPA 286 (ICC-ES AC12 Appendix B)

• Tested per NFPA 285 to comply with IBC Section 2603.5.51

• 1, 2, 3 or 4-hour Fire Rated Assemblies as shown in the UL Fire Resistance Directory.

Top Rmax Products and Their Applications

DURASHEATH® - continuous insulation for exterior walls.

ECOMAXCI® FR (REPLACES TSX-8500) - commercial exposed wall/ceiling applications.

ECOMAXCI® FR AIR BARRIER (replaces ECOMAXCI®) - continuous insulation for commercial exterior walls and use with the ECOMAXCI® wall solution.

ECOMAXCI® FR PLY - fir resistant continuous insulation for cladding attachments in commercial exterior walls.

ECOMAXCI® PLY (REPLACES ECOBASECI™) - continuous insulation for cladding attachments in commercial exterior walls.

EVOMAXCI™ - continuous insulation for use with the evo architectural panel system.

R-MATTE® PLUS-3 - a SIKA® residential insulation for wall/ceiling multi-applications. Available at local big box retail locations. 

THERMABASE-CI™ - structural continuous insulation for cladding attachments in residential exterior walls.

THERMASHEATH® - commercial or residential wall/ceiling applications.

THERMASHEATH®-SI - structural insulation for residential exterior walls

TSP® - durable glass fiber reinforced aluminum facers for commercial and residential applications.

TSX-8510 - commercial exposed wall/ceiling applications.