Understanding Vapor Barriers

Building Science, Insulation

Before you start any project, understanding vapor barriers is a must. This ensures that the insulation will be installed correctly. Sadly, that is not always the case.

Many homeowners want to save money, so they install the insulation themselves. Or, they hire licensed professionals who haven’t been educated on the proper installation techniques. But, the biggest mistake we see is people installing a double vapor barrier—installing a covering (usually plastic) over an already existing vapor barrier.

Understanding vapor barriers

“The function of a vapor barrier is to retard the migration of water vapor. Furthermore, vapor barriers are not typically intended to retard the migration of air. That is the function of air barriers.”[1]

Moreover, a vapor barrier is any material used for damp proofing, typically a plastic or foil sheet. Additionally, these sheets resist diffusion of moisture through the wall, floor, ceiling, or roof assemblies of buildings.[2]

What does a vapor barrier do?

Vapor barriers are installed along, in, or around walls, ceilings, and floors. Of course this is done to prevent moisture from spreading and potentially causing water damage. Additionally, a true vapor barrier is one that completely prevents moisture from passing through its material, as measured by the “moisture vapor transmission rate.” If the material has any porousness, but the barrier still provides protection from moisture, it is called a vapor diffusion retarder.[3] Furthermore, vapor retarders also are commonly referred to simply as vapor barriers. The barrier terminology is less accurate because, in most cases, the products don’t completely barricade the vapor.

What can I use as a vapor barrier?

There are a wide number of materials available to create effective vapor barriers, including:

Elastomeric coatings
Aluminum foil
Paper-backed aluminum
Polyethylene plastic sheet
Asphalt-coated Kraft paper
Metallized film
Vapor retarder paints
Extruded polystyrene or foil-faced foam board insulation
Exterior grade plywood
Sheet-type roofing membranes
Glass and metal sheets[4]

Where do I need a vapor barrier?

The IRC (International Residential Code) divides North America into eight climate areas. This is done for the purposes of determining when a vapor barrier might be needed in a building. Additionally, the IRC recommends builders install a Class-I or -II vapor barrier on the interior side of homes in climate zones 5 and above, and in the Marine 4 zone. However, if you air condition your house in the summer, you might trap condensation in your roof or walls for part of the year. If this is the case, be sure to use a Class-II vapor barrier on the interior of the wall. Moreover, you can use a Class-III vapor barrier on the interior. Pair that with spray foam insulation on the interior of the wall or roof. Furthermore, when building in hot, humid climates (zones 1 to 3), you should not have a vapor barrier on the interior side of the wall.[5]

Major Problem

Incorrect use of vapor barriers is leading to an increase in moisture-related problems. Vapor barriers were originally intended to prevent assemblies from getting wet. However, they often prevent assemblies from drying. In like manor, vapor barriers installed on the interior of assemblies prevent assemblies from drying inward. This can be a problem in any air-conditioned enclosure, below grade space, or a vapor barrier on the exterior. Additionally, a problem can occur where brick is installed over building paper and vapor permeable sheathing.[6]

Building in a Cold Climate While Adhering to Building Codes

Is a vapor barrier required in New England? Yes! Not to mention that as a builder your first step is to consult your local and state building codes. In many colder North American climates, vapor barriers are a required part of building construction.

You may find that vapor barriers are often not required in warmer climates. And, if installed in the wrong climate or on the wrong side of building materials, a vapor barrier can cause more harm than good. By the same token, this circumstance may prevent water vapor from drying, which in turn can cause rot and mold.[7]

If you don’t know the building requirements for your area, ask an expert!

Double Vapor Barrier – Don’t Do It!

What is a double vapor barrier? The insulation in Photo A was installed by an inexperienced insulation installer. Additionally, the brown paper on the fiberglass is a vapor barrier. By putting poly plastic over everything, the installers created a double vapor barrier. Not to mention that this type of installation creates future moisture, mold, and rot problems. Moreover, in Photo B the cellulose netting is not strapped and it is starting to sag. Furthermore, the staples are ripping out and the ceiling could come down at any time!

In conclusion, if you need insulation, contact us and let us decide what type is best. Let us do the thinking for you!

[1] Building Science (2011). BSD-106: Understanding Vapor Barriers. Retrieved from buildingscience.com.
[2] Wikipedia (2019). Vapor Barrier. Retrieved from en.wikipedia.org.
[3] Energy.gov (2019). Vapor Barriers or Vapor Diffusion Retarders. Retrieved from energy.gov.
[4] Energy.gov. Vapor Barrier
[5] Fine Home Building (2009). How It Works: Vapor Drive. Retrieved from finehomebuilding.com.
[6] Building Science, BSD-106.
[7] IKO Commercial, (2019). An Introduction to Vapour Barriers and Vapour Retarders. Retrieved from iko.com.

Why You Need Blower Door Testing

Blower Door Testing, Building Science, Energy Efficiency, News, Save Money, Thermal Bridging

Blower door testing helps us understand where structures leak and is the first step toward building tighter, more energy-efficient homes.

What is a blower door test?

The purpose of Blower Door Testing is to measure the air tightness of a home and check for air leakage. A blower door is a powerful fan that mounts into the frame of an exterior door. The fan pulls air out of the house, lowering the air pressure inside. The higher outside air pressure then flows in through all unsealed cracks and openings.

Blower Door Testing Diagnostic Tool - The Green Cocoon Insulation — Image courtesy of energy.gov/.

These are some reasons for establishing the proper building tightness:

Reducing energy consumption from excess air leakage
Avoiding moisture condensation problems
Avoiding uncomfortable drafts caused by cold or warm air leaking in from outside
Controlling outdoor contaminants, pests, and odors from entering your home.
Determining proper sizing and airflow requirements of heating and cooling equipment.
Determining whether mechanical ventilation is needed to provide acceptable fresh air and maintain indoor air quality in your home.

Determine the air infiltration rate

While the blower test is being conducted, our insulation specialist may use an infrared camera to look at the walls, ceilings, and floors. Moreover, this test finds specific locations where insulation is missing and air is leaking.

Preparing for a blower door test

Our experienced insulation specialist performs the blower door test. This includes a walk-through of your home, setting up the blower door, and conducting the test. The following steps will help prepare your home for a blower door test:

Plan to do a walk-through of your home with the specialist. Be prepared to point out areas that you know are drafty or difficult to condition comfortably.
Expect the specialist to request access to all areas of your home including closets, built-in cabinets, attics, crawl spaces, and any unused rooms.
The specialist will need to close all exterior doors and windows, open all interior doors, and close any fireplace dampers, doors, and woodstove air inlets.
If you heat with wood, be sure all fires are completely out – not even coals – before the specialist arrives. Remove any ashes from open fireplaces.
Expect the specialist to set controls on all atmospheric fossil fuel appliances (e.g., furnace, water heater, fireplaces, and stoves) to ensure that they do not fire during the test. The specialist should return them to the original position after the test.
Expect the test to take up to an hour or more, depending on the complexity of your home.

The Green Cocoon offers custom, cost-effective solutions to make your home or office building more comfortable. Additionally, this saves you money on your energy bills. Our troubleshooting and diagnostic skills separate us from the pack! For more information, contact us

Blower Door Testing

Importance of Vapor Barriers and Ventilation

Building Science, News

Recently, our vice president Candace was asked to take a look at a property and give a quote for insulation. Our sales staff usually videotapes their meetings with clients to help them decide on the best insulation for the job. We wanted to share this video to show you the importance of vapor barriers and ventilation.

Thermal Bridging and Condensation

In the first part of this video, you will see water droplets dripping off the nails that are poking through. Because the nails were put in from the outside on the north facing part of the house where there is not a lot of sunlight, there is thermal bridging. Consequently, any moisture that comes in is hitting the wood and making it wet. But the nails are where the water is condensing. As the water runs down the wall and gets closer to the floor, you can see that there is frost in the soffit. Because heat rises, the soffit is much colder.

Add a Vapor Barrier

Adding ventilation can temporarily solve this problem, but then heat and moisture would be pulled from the house even faster. And, losing heat is not energy-efficient. What should happen is a vapor barrier should be created at the thermal envelope to prevent the moisture from ever getting into the space. The other alternative is to spray foam the roof so the surface of the roof is protected by the foam. And because of its R-value, the surface of the foam will never be cold enough for the moisture to reach a dew point and condense.

At 38 seconds, you will see that on the other side of the house, there is an identical eve space that is significantly warmer. In fact, it is 20 to 30 degrees warmer, and there is no moisture. Consequently, the nail heads don’t show any rust. This is a good example of why vapor barriers and ventilation are important.

Insulation Is Key

Our recent blog about Rockwool insulation being designed for use as exterior continuous insulation is a great read. It will help you understand the importance of vapor barriers and ventilation.

If you have questions about our products, check out the FAQ section of our website. You may find your answers there. If not, contact us!

Watch the video on our YouTube Channel!

Why Proper Attic Insulation Is Crucial

Building Science, Energy Efficiency, Save Money

Your attic does much more for your home than store your stuff. It is designed to provide a protective barrier for your home from cold, heat, and humidity. But in order for your attic to do its job, it must be properly insulated.

Traditional Insulation Not Effective

The Green Cocoon has almost two decades installing insulation and has discovered that traditional insulation isn’t effective in most cases! The most common types of insulation used in one’s attic are fiberglass and blown cellulose. The problem with those types of insulation is that many inexperienced contractors install them without sealing to prevent airflow. With fiberglass or cellulose, air can move quickly through the insulation and with that air comes moisture.

green-cocoon-nh-attic-insulation — Improper attic venting causes mold and moisture issues. Baffle vents were present but soffits were blocked.

Escaping Heat Causes Problems

If heat is escaping into the attic from below, and the attic is not properly vented, the warm air will heat the roof causing ice d am s to form. Some contractors try to fix ice dams by increasing the ventilation in the attic. But what they should be doing is putting in proper insulation! It’s all about the R-va l ue.

In New England, the R-value requirements for an existing attic is R-38, but for new construction it requires a value of R-49! That’s because newer construction techniques are becoming more efficient.

Did you know that R-value is measured in an air-tight vacuum chamber and allows researchers to conduct physical experiments without any interference from the environment? Your wall is not a vacuum chamber and the materials do not perform the same in the real world, unless completely air-sealed like the chamber. R-value is not constant, so it’s important to use the right type and amount of insulation.

Closed Cell Spray Foam Recommended

Closed cell spray foam is the only insulation material approved for spraying directly against the roof deck because moisture can’t pass through it. This, along with the fact that the foam fills the holes and crevices, makes it the best insulation choice to prevent condensation in the attic.

The Green Cocoon Attic Insulation NH — Nails are rusty and sheathing is rotted. Closed cell spray foam to the rescue!

Proper Ventilation

If you have properly insulated and air-sealed your attic, you won’t have heat loss or moisture build-up. We suggest installing a soffit and ridge vent, or two gable vents to help with air circulation, if you have an uninsulated roof.

If your attic is insulated with fiberglass or cellulose, and you have insulation covering the roof slopes, you need to have a vent behind it. As mentioned above, moisture can potentially pass through the insulation and condense on the roof causing a host of issues.

Reasons Not to Ventilate

If you have HVAC and/or ductwork in the attic, you don’t want to vent the attic because you will lose a lot of efficiency. The heating system will try to warm the house from a 10-degree attic and cool it from 130! A conditioned attic will prolong the life of your equipment as well as save you money with your heating and cooling bills.

Start Right and Properly Ventilate

If you have fiberglass or cellulose insulation already installed, then it is crucial that you have adequate and proper ventilation. But, upgrading your insulation saves money and efficiency in the long run. Don’t use ventilation as a way to solve inefficiencies with subpar insulation. That’s like putting a band aid on a bullet wound!

If you want more information on how we can help you, con t act us.

Thermal Imaging Cameras: Where and Why We Use Them

Building Science, Energy Efficiency, Insulation, News, Save Money, Thermal Bridging

The Green Cocoon has many tools in its arsenal to help you stay warm and save you money. One of those tools is a thermal imaging camera. Where and why do we use it? We use it when we come to your home to evaluate your space. We use the camera to show you where cold air is coming in. Also, the camera comes in handy when we need to discover if there is insulation inside a wall or ceiling. We don’t have to guess. The camera tells us!

What is a thermal imaging camera?

Thermal imaging cameras are devices that translate thermal energy (heat) into visible light. This is done in order to analyze a particular object or scene. Furthermore, the image it produces is known as a thermogram. The analysis of a thermogram is done through a process called thermography. Thermal imaging cameras are sophisticated devices that process the captured image and display it on a screen. The image can be used for immediate diagnosis. Or, they can be processed through specialized software for further evaluation, accuracy, and report output. Consequently, thermal imaging cameras take measuring temperature to the next level. Instead of getting a number for the temperature, you get a picture showing differences in temperature.[i]

green-cocoon-thermal-imaging-2 — Here we see a completely uninsulated wall bay

green-cocoon-thermal-imaging-3 — This photo illustrates how much cold comes through an outlet switch cover that isn’t properly air sealed and insulated

Thermal imaging camera applications and uses

The first commercial thermal imaging camera sold in 1965 for high voltage power line inspections.[ii] Since then, thermal imaging cameras have been used in many fields. Firefighters use them to see through smoke, find people, and localize hotspots of fires. Additionally, physiological activities can also be monitored with thermographic imaging. Fever in human beings and other warm-blooded animals is just one of many. Building construction technicians can see heat leaks to improve the efficiencies of cooling or heating. Additionally, thermal imaging cameras are a common tool used by home inspectors.

Camera used in our evaluation

When our salesperson comes to evaluate the space you would like to insulate, they will be using a Thermal Imaging Camera. Having a tool that instantly shows a client where and how much insulation is needed, is invaluable. Contact us to schedule an appointment.

[i] Grainger. Thermal Imaging Cameras Explained. Retrieved from grainger.com. [ii] Wikipedia. Thermographic Camera. Retrieved from Wikipedia.org.

Polyurethane Foam Used as a High-Performance Adhesive

Building Science, Insulation, Roof Health, Save Money

In the insulation industry, we all know why spray polyurethane foam works so well as an insulation and air barrier for buildings. Most also know that polyurethane is used to make many everyday objects in your automobile and around the house. But, most don’t know that polyurethane foam is used a lot as a high-performance adhesive.

Closed Cell Spray Foam Strongest

If you mix the A and B sides of polyurethane foam together, the curing liquid sticks to everything. This creates a strong bond with most any type of surface. In a foam form, the curing polyurethane adhesive rises to fill small gaps between irregular surfaces. This is closed cell spray foam. It reduces excess waste and energy consumption in buildings by up to 50% while adding strength—R-value (7 per inch).

Used in Construction Industry

This high-performance polyurethane adhesive has found a permanent home in the construction industry. Roofing contractors regularly use polyurethane adhesives to attach various roofing materials to substrates (see SPFA-142).

Polyurethane adhesives are also used to bond gypsum board to framing, especially in manufactured housing applications. Two inches of closed cell spray foam between wall stud framing can provide nearly the same racking strength as a half inch of oriented strand board (OSB) sheathing, according to sprayfoam.com. The same application of closed cell foam below the roof deck, between the rafters and trusses (new construction or retrofit), can increase the wind uplift resistance by a factor of three. It can also provide a secondary water barrier if the roof shingles fail.

The Insurance Institute for Business and Home Safety (IBHS) recognizes the structural benefits of closed cell foam insulation and polyurethane adhesives in their Fortified Construction Standards program.

Homeowners Save Money

Understanding all of the benefits of closed cell spray foam is key for homeowners. The knowledge helps them make better decisions regarding insulation choice when building or remodeling their home. Moreover, as we strive to construct more resilient and eco-friendly buildings, we encourage the use of spray foam in most of our projects.

Ice Dams and How to Prevent Them

Building Science, Home Maintenance, Insulation, R-Value, Roof Health

Does your house have icicles hanging from the roof during the winter? If so, there is something going on that could potentially cost you thousands of dollars. It is called an ice dam and here’s how to prevent them.

What is an ice dam?

If the attic isn’t properly insulated, during the winter the warm air will escape and melt the first layer of snow on your roof. Many uneducated contractors will tell you to increase your attic insulation to prevent ice dams. While this may slow down the buildup of ice dams, it will essentially increase the speed of your heat loss. Consequently, the heat loss will make your home less efficient.

DIYers (do-it-yourself) like to solve the problem by putting heat tape on the roof, but that can be incredibly damaging to the shingles. Furthermore, the tape does not solve the problem, which is inefficient insulation and heat loss.

The layer of snow that is against the roof will melt and run down the roof shingles. You can’t see this happening because it is under the pile of snow. Once the water reaches the overhang where it is colder, an ice dam starts to form. This process happens over and over; the ice dam gets bigger; and the water gets higher. Eventually, water will get under the shingles!

As the melting continues, the ice dam and water lift the shingle more and more. Eventually, it hits the top of the shingle. That is when water can get into your house, and potentially cause thousands of dollars in damage.

How to prevent ice dams

Whether you are creating a conditioned or unconditioned attic, we recommend the same things.

Seal the gaps – First you need to air seal any gaps or holes in the floor or roof. There are several products that we suggest you use. Please contact us so we can help you decide which product is best for you.
Use correct R-value – Make sure you have enough R-value. Remember, fiberglass doesn’t have a constant R-value so we don’t recommend it. In southern New Hampshire, you need a minimum of an R-49.
Ventilate the attic – If you plan to insulate the attic floor, make sure to allow for proper ventilation to prevent condensation. If you are not sure you have adequate insulation, give us a call and we will come out and take a look.

Using a spray foam in the attic is the best choice because it fills the holes and crevices. We recommend closed cell spray foam for several reasons:

It has a higher R-value per inch than open cell spray foam.
Closed cell spray foam is a vapor barrier and water can’t permeate it.
It sticks to the walls and fills all the crevices and holes.

To learn more about Closed Cell Spray Foam, watch our video on YouTube.

Don’t Make These Basement Insulation Mistakes

Building Science, Insulation, Save Money

Incorrectly installed basement insulation is a common error. We see this problem not only with do-it-yourself installation, but also with contractor installation. The results can be disastrous as severe mold and mildew may become a problem, not to mention the loss of money on your heating bill. This is why we beg you, “don’t make these basement insulation mistakes.”

Use Treated Lumber

Since most basements are inherently moist, you need to keep all untreated wood away from the concrete surfaces. Moisture below the slab can wick up into the concrete and get to the base plates of the wall. Therefore, you need to make certain the bottom plate of the wall is treated lumber.

Avoid Using Fiberglass Insulation in Basements

As seen in the photo above, putting polyethylene over fiberglass insulation is a no-no as it doesn’t allow the insulation to breathe. Consequently, this homeowner had moisture build-up and ultimately mold growth!

For years contractors have been treating basements much like regular living space. It’s not uncommon to see fiberglass insulation in direct contact with basement foundation walls. Here in the northeast, we see several common mistakes, including:

Plastic vapor barrier against concrete wall, fiberglass insulation inside stud wall, then drywall
Fiberglass insulation inside a “bag” hanging from the rim joist down along the foundation wall
Stud wall filled with fiberglass insulation an inch or two away from the concrete wall^[1]

Those mistakes can increase the chances for mold to grow.

What Causes Mold to Grow in Basements?

Mold can grow on virtually any organic material as long as it has the right moisture level and oxygen. Because mold eats or digests what it is growing on, it can damage a building and its furnishings. If left unchecked, mold eventually can cause structural damage to building materials and can cause health problems. That’s why we don’t want mold in our basements! Specifically, we can prevent damage to buildings and building contents in the basement areas, save money, and avoid these potential health problems by controlling moisture.

According to the EPA, indoor relative humidity in homes should be kept below 60 percent — ideally between 30 and 50 percent. ^[2] In addition to preventing mold formation, maintaining the correct humidity levels may also have a bonus effect. It may discourage pests such as cockroaches, silverfish (bristletails), and dust mites from showing up where you don’t want them!

To measure the humidity of your home or basement, you need to buy a humidity meter and track the relative humidity level. That is the first part of understanding the mold problem in your home or basement.

Education Needed

If contractors are still using fiberglass insulation in basements, it means that we in the industry need to do a better job educating our builders. In order to understand the issues with basement insulation, you first must understand the role of vapor barriers in basements.

Use the Right Insulation

Over the years, we’ve come to rely on two main approaches for basement insulation projects and remodeling, including closed cell spray foam and rigid foam board. When installed in the correct thickness, these two methods result in a proper vapor barrier and superior insulation.

Get Educated – Be the Pro!

Today, the building industry and building science are changing rapidly. In order to stand out in the competition and provide a professional service to your clients, you need to stay educated on the latest methods. You can be sure that the team at The Green Cocoon is up-to-date on the latest insulation practices in order to bring our clients the best product possible.

If you have questions or need a quote on your next insulation project, contact us and we’d be happy to help.

^[1] Be the Pro. Avoiding Basement Insulation Mistakes. Retrieved from bethepro.com.

^[2] United States Environmental Protection Agency. Mold Course Chapter 2. Retrieved from epa.gov.

Prepare for Frosty Flip-Flop Winter with Eco-Friendly Insulation

Building Science, Insulation, Save Money, Weather

According to Farmers’ Almanac (Almanac), we are in for a “Frosty Flip-Flop” winter. The term was inspired by the predicted polar coaster swings in temperatures! With the temperature cooling, it is the perfect time to save money and prepare for the frosty flip-flop winter with eco-friendly insulation. Make your home more energy-efficient by replacing your old insulation one of The Green Cocoon’s eco-friendly insulation.

New Hampshire Known for Crazy Weather

If you live in New Hampshire, you are no stranger to crazy winter weather. According to NOAA’s National Centers for Environmental Information, the coldest temperature on record in New Hampshire (-50°F) was on January 22, 1885. That was at the summit of Mount Washington. Likewise, many winters in New Hampshire bring snow, rain, ice, and chilly temps. So, you need to prepare for that frosty flip-flop winter with eco-friendly insulation.

The Almanac is forecasting a “winter whopper” for parts of the Northeast and Ohio Valley toward the end of February. What does that mean for us this winter? We will experience colder than normal temperatures, and significant precipitation.

Use Eco-Friendly Building Insulation

Many homeowners don’t realize how effective insulation can be at making their homes more comfortable and efficient. Insulation in key areas like the attic, basement, and exterior walls slows heat transfer in and out of the home. This means that in the winter, that valuable heat you’ve paid for stays inside your home, right where you want it. Cellulose and spray foam insulation are especially effective insulation materials.

With the right insulation upgrades, you can expect benefits like:

Fewer drafts and cold spots
Warmer floors
Lower annual heating/cooling costs
Enhanced overall comfort
Greater home energy efficiency
Reduced outside noise

When insulation is paired with proper air sealing to eliminate air leaks, the benefits go even further! So don’t keep throwing your money out the window. The Green Cocoon has eco-friendly building insulation that comes in various forms. We have what you need!

Did You Know? Insulation R-Value Changes

Building Science, R-Value

In the world of building construction, improvement, and insulation, we talk about R-value all the time. Usually, we talk about it as if it’s a constant number. We see R-19 stamped right there on the product, so that’s what it is, right? Well, did you know that the insulation R-value changes?

What Is R-Value?

R-value is a measure of resistance to heat flow through a given thickness of material. Furthermore, it is important, but it’s just one of a few key factors that determines the effectiveness of an insulation material. R-value is tested in an air-tight vacuum chamber, which means that typical insulation materials like fiberglass and cellulose do not actually perform with that value unless paired with intense air sealing measures.

^[1]

How Is R-value measured?

Because of scams involving R-value claims that didn’t match reality, the U.S. Federal Trade Commission (FTC) devised the R-value Rule to protect buyers of insulating products. In fact, in 2013 the FTC handed down its largest fine ever ($350,000) to a company claiming that its paint had an R-value of 100.^[2]

So, the R-value Rule requires testing insulation using one of four American Society of Test Methods (ASTM) standards. The basic requirement is that the mean temperature must be 75° F (24° C) with a temperature difference of 50° F (28° C) across the insulation.^[3]

According to Building Science Corporation, most R-value testing is done with a temperature of 50° F (10° C) on the cold side and 100° F (38° C) on the hot side.^[4]

The Lowdown on R-value

The main point here is that R-value isn’t some constant number for a given material, and installation isn’t the only factor that affects it. As you can see above, temperature has a significant effect as well.

The team at The Green Cocoon knows that the performance of the insulation is affected by how well it is installed. Energystar.gov has developed guidelines for grading the quality of installation. Moreover, they’ve developed a table that shows what levels of insulation are cost-effective for different climates and locations in the home.^[5]

Compression

Improperly installed insulation loses its R-value. For example, fiberglass can lose up to 50 percent of its prescribed R-value when compressed. Additionally, when you compress fiberglass batt insulation, the R-value per inch goes up, but the overall R-value goes down because you have less inches or thickness of insulation.^[6]

Fear not, closed cell spray foam is the only insulation material that has an almost constant R-value. The reason is because you cannot pass air through it or compress it.

[1] Building Performance Institute (April 4, 2017). What Does R-Value Mean? Retrieved from bpihomeowner.org.

[2] FTC.gov (January 31, 2013). FTC Action Leads to Court Order: Home Insulation Marketer to Pay $350,000. Retrieved from ftc.gov.

[3] Electronic Code of Federal Regulations (March 31, 2020). R-value Rule. Retrieved from ecfr.gov.

[4] Building Science Corporation (April 12, 2013). Info-502: Temperature Dependence of R-values in Polyisocyanurate Roof Insulation. Retrieved from buildingscience.com.

[5] Energy.gov. Recommend Home Insulation R-Values. Retrieved from energy.gov.

[6] Insulation Institute. The Facts About Compressing Fiber Glass Insulation. Retrieved from insulationinstitute.org.

Category: Building Science