Roof Insulation: Explore 5 Different Options Available

Roof Insulation

Whether it is in the middle of summer, when the temperature soars up, or in the middle of winter when the temperature falls really, really low, great roof insulation comes with a lot of advantages. 

During the summer, it will ensure that the heat outside is not felt inside. And when it gets to that time of the year to bring out the sweater and jerkins, insulating your roof is a sure-fire way to ensure that it doesn’t get too cold inside. You can feel cozy and warm inside even during the winter months if you insulate your roof.

Insulating your roof or attic is not just for improving the overall healthy atmosphere within your home. It can also help you with cost-cutting and energy conservation. Poorly insulated attics or roofs mean the warm air will escape through the attic and reach the rooftop. So, during the months when snowfall is heavy, this warm air will melt all the ice gathered on the roof leading to the roof getting damaged. Let’s dive into more about the benefits below.

Benefits Of Roof Insulation

Did you know that 35% of heat loss occurs in a home all because of your roof? No wonder insulating your roof is so important!

  • Insulating your roof helps save money and energy.
  • Prevents damage to the roof because of ice dam build-up caused due to rising heat melting the snow gathered on the roof.
  • Stops general build-up of moisture due to rain or now. Now, moisture build-up is one of the leading causes of roof damage.
  • It helps keep noise levels down during harsh weather conditions like heavy winds, rain, hail, and storm. 
  • It is more sustainable, reduces the impact on the environment by reducing CO2 emissions.

Did you know that a properly insulated roof will help to save 10 to 20% on your heating bill? 

If you have decided that yes, you definitely need insulation for your roof, then you can DIY or hire the help of a professional. Let’s look more into how to do that in the following sections.

R- Values For Insulation

A quick read-up of your state’s building codes and you can determine what R-value climate zone you belong to. This will have an impact on your insulation needs.

So, what exactly is R-Value?

R-value is nothing but a measure of the insulation’s ability to resist heat. A higher R-value means more effective will be the insulation type you go with.

R-value is a measurement system that will grade your insulation based on how effectively they keep the heat from entering or leaving your home. Hotter regions have a lower R-value than the cooler regions. Consequently, the type of insulation you need to go for will vary. Colder regions require a higher R-value. This can be increased by layering insulation.

Top 5 Best Insulation Options

Here is a rundown of the best insulation options you have at hand. We will lay down the pros and cons of each, so you can choose one based on your specific needs.

Spray Foam Insulation: Open and Closed Cell SPF

Spray foam is one of the best and most effective insulation options you have at hand. If you want thorough insulation, you cannot do better than Spray Foam Insulation. Spray foam is nothing but a liquid made with polyurethane and isocyanate, which when applied will give a durable layer of foam insulation.

You can use Spray Foam Insulation to fill cracks, cavities, gaps, and any nook and corner where you think there will be air leaks. This type of insulation will help to prevent moisture. And we know moisture will lead to mold and mildew formation. Not only will Spray Foam Insulation help with moisture prevention, but it is also highly effective in resisting heat, wind, cool air and sound from entering in.

Now, there are two types of Spray Foam, each with its own R-Value. Closed-Cell Spray Foam and Open-Cell Spray Foam. 

Closed-Cell Spray Foam: The density of closed-cell spray foam is higher and so is the R-value. The R-value is 4.9 to 7.1 per inch.

This makes them more expensive. In closed-cell foams, the cells are tightly pressed together making them super rigid. It is highly effective for larger areas, to keep moisture out of your home. 

Open-Cell Spray Foam: Open cell Spray Foams have a lower density and the corresponding R-value is also lower. The R-value is 3.5 to 3.6. So, they are a lot less expensive. Here, the cells are intentionally left open so as to make the foam nice and soft. It is ideal for places with milder climates, and for preventing unwanted sounds from entering in. 

Pros of Spray Foams:

  • You can cover larger areas indoors or on your roof, and spray foams are one of the best options when it comes to insulating every nook and corner of your roof. As all the gaps are sealed off, moisture, wind, hot or cold air will have a hard time seeping in.
  • Spray Foam will help to improve the energy efficiency of your home. This means fewer carbon emissions, and therefore the negative impact on the environment is also reduced. (Environmental enthusiasts, take note!)
  • They last really long because of the properties of the Spray Foam. When applied, the cells of the Spray Foam will expand and harden to seek out any corner or nook that may be leaking air, and then never lose shape!

Cons of Spray Foams:

  • They are on the more expensive side.
  • They are rather messy.
  • You cannot apply Spray foams on your own, you need to hire the help of a contractor to do it for you. It is because, although the application looks straightforward enough, spray foams are made with strong chemicals which could lead to issues on the eye, skin, and lungs if you don’t wear proper protection.
  • Spray Foams are energy-efficient, so although you will get to save energy, it is still a costly option because of the upfront insulation installation money you will have to shell out to the contractor you hire. The upfront cost you have to pay to your contractor is around $2000.

Loose-Fill Or Blow-In Insulation

Loose-Fill or Blow-in Insulation is about as common as the first option on this list. Loose fibers of recycled waste materials are gathered and packaged in bags or flexible tubes. This could be cellulose or fiberglass fibers. Think of those unfinished attics or wall cavities in your home that require insulation. Fiberglass blown-in or Cellulose Blown-in could be a great option for you.

The cellulose or fiberglass insulation is then blown into the required place to the depth and density that is required. You can of course pour the fill in place and spread it by hand, but then it would require a lot of effort on your part. And for all that, the result won’t be all that effective!

Fiberglass blown-in or loose-fill insulation: Fiberglass has a lower R-value of 2.2 to 2.7 per inch. It is made out of recycled glass, sand, and other materials.

Cellulose blown-in or loose-fill insulation: Cellulose has a higher R-value of 3.2 to 3.8 per inch. Cellulose is made with 80% recycled paper, and it is used as an alternative to Fiberglass.

Pros of Fiberglass blown-in insulation:

  • Despite the glass material that goes into making fiberglass insulation, blown-in fiberglass is completely resistant to fire.
  • There are concerns about its safety, but they do not cause any issues with breathing. They do not fall under the category of carcinogens either.
  • They are affordable and the insulation installation is fairly easy.
  • With the latest innovation, manufacturers are now using 30% recycled glass in their fiberglass insulation. So, this makes it an eco-friendly option.

Cons of Fiberglass blown-in insulation: 

  • The small shreds of glass in Fiberglass blown-in may irritate your skin. Although not a carcinogen, if inhaled often, they may lead to respiratory issues, so we highly recommended you to wear masks and other protective gear when you go with fiberglass insulation.
  • As time passes, the R-value of fiberglass goes down by up to a whopping 50%. When this happens, it will start absorbing moisture and the insulation effectiveness will also be greatly diminished. 

Pros of Cellulose blown-in or loose-fill insulation:

  • Cellulose also tends to settle and flatten, and lose some of its R-value. But it is nowhere as near as how much Fiberglass loses, and so it is a better option for colder climates. So, it is more durable than the fiberglass blown-in option. 

Cons of Cellulose blown-in or loose-fill insulation:

  • Made out of recycled paper or newspaper, it is flammable. You may need to treat it with either borate or ammonium sulphate chemicals so that they become less combustible.
  • The use of chemicals means they are not as eco-friendly despite being made out of recycled material. 

Insulation Blankets: Batt and Roll Insulation

Batt and Roll Insulation is commonly used to provide insulation for your roofs and attics. 

The pre-cut lengths of Batts make them quick and easy to install. These panels are good for noise control as well. Batts are ideally used for framed spaces.

Rolls are a flexible insulation material that comes in 2 standard thicknesses, namely 16 and 24 inches. The fiber material is prefabricated into a blanket roll and pressed between two paper or foil sheets. The more the insulation requirement, the more layers you can add. Rolls are perfect for long stretches, so for covering the entire attic, rolls are more suitable.

Fiberglass and mineral wool are the most common materials used. 

The R-value lies between 3 and 3.3 for mineral wood. 

Pros of Batt Insulation:

  • Even a layman with no knowledge can install the Batt insulation.
  • They are very affordable.
  • You can find them in any home improvement store. Affordability is not an issue at all.
  • They are easily portable.
  • No matter the size of your ceiling joists and rafters, these can be used for providing the best possible insulation.
  • Fiberglass batts are good at preventing moisture leakage and hence your roofs will not be damaged. They are well suited for humid climates where the chances of moisture seeping through and damaging the roof are high.
  • No fluctuation in R-value as opposed to loose-fill insulation and hence stable insulation.

Cons of Batt Insulation:

  • As we saw in a previous section, fiberglass could lead to skin irritation. If you are DIYing your own batt insulation, then make sure you are wearing protective gear and respiratory masks.
  • The R-value of batt insulation is rather low, and so you cannot use them efficiently in very cold areas. You may actually have to go with several insulation layers.
  • They are not all that energy efficient. Since they use up a lot of energy, they are not one of the most sustainable or eco-friendly roof insulation processes out there.

Rigid Insulation(Foam) Board

Rigid foam boards are a lot more expensive than the previous roof insulation type for more reasons than one. The R-value is a lot higher. With sound-proofing capabilities, it is one of the best insulating materials available currently. 

Rigid and not all that easy to move around, you may think that they may pose a challenge to carry around your building’s tight corners and other areas that are difficult to access. But worry not; the roofing will be placed right on top of this insulation board, and you will not face this problem at all. In fact, this is the only exterior insulation option on this list.

There are 3 main types of rigid foam boards:

1. Polyisocyanurate or Polyiso

2. Extruded Polystyrene (XPS)

3. Expanded Polystyrene (EPS)

The highlight of Rigid Foam boards is that you can use them anywhere in your homes such as roofs, basements, garage, attics, and your living room.

Foams made out of Polyiso are expensive for good reasons. With the highest R-value, they provide the best insulation. These feature a foil facing which will act as a radiant obstruction. They are moisture-resistant as well.

XPS is made out of plastic and comes in blue or pink color options. Like the previous option, they prevent moisture from leaking through. But it comes with one drawback; the main insulating material can catch fire. Do make sure to not overexpose them to sunlight.

There is not much of a difference between EPS and XPS except that the former has a lower R-value. This is because some insulation bits are missing. These voids, however, make insulation less efficient than it could have otherwise been. It is one of the more affordable options though.

The following are the R-values for the 3 types of foam insulation boards:

Polyiso – R-6.5-6.8 per inch

XPS – R-5 per inch

EPS – R-3.8 per inch

Pros of rigid insulation boards

  • Insulation boards have high density and great water resistance. This translates to a greater R-value. 
  • They come in the form of large, solid sheets and so you can fix them to areas in your house that require insulation without any effort.
  • Some of the materials that go into making these boards include wood, straw, and cork. So, you guessed it; they are eco-friendly to boot!

Cons of rigid insulation boards

  • Prolonged exposure to sunlight may cause the rigid foam to deteriorate.
  • The chemical flame retardants added to the insulation boards for safety could harm your health. What’s worse, they could end up causing serious health issues like cancer and even affect your reproductive health.


As a homeowner, roofing is one of the most important considerations in building your dream home. But there is more to roofing than just the type of roofing material, color and roofing style. Insulation is just as important as anything else. We hope this guide will come in handy in picking the best roof insulation based on the R-value climate zone your home is at. 

Whatever option you choose to go with, we’re sure it will help to reduce your heating bills, lower the emission of greenhouse gases, prevent moisture from seeping in, provide protection from adverse weather conditions like hail, storm, snow, and rain, soundproof your home when the weather conditions outside are less than ideal, and help to keep your home in an optimal temperature, meaning cozy and warm during winter, and cool during the sweltering hot summer days. 

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