Did you know that a quarter of the heat in your building escapes through the roof?
If your roof isn’t insulated, you can think of it as money flying off into the air and vanishing.
Losing such an enormous quantity of accumulated heat calls for urgent roof insulation to retain home warmth, improve energy efficiency and reduce heating bills.
Here, we’ll walk you through the benefits of insulating your roof, cover the pros and cons of different types and share our expert pick on the best type of insulation for your roof.
Roof insulation has a long lifetime — when installed correctly, it lasts around 40 years and pays for itself in less than five years.
Figures like that certainly make a convincing case for insulating your roof and attic, and that’s only a small part of the many long-term benefits you can reap from the upgrade.
If a building is not properly insulated, 25% of heat escapes through the roof of the building.
Hot air rises and leaves the attic, where the process can be facilitated due to the presence of holes, cracks and ventilation issues such as missing intake vents and exhaust elements.
Thermograms define other sources of heat loss as follows:
- Doors and windows – 25%
- Outside walls – 35%
- Ground floors – 15%
Additionally, smaller air leaks may appear practically anywhere, from electrical outlets and around plumbing spaces to light installations and locations where pipes have been installed.
Using an infrared scanner can help you identify the problematic areas so that you check thoroughly for air leaks, cracks, holes and foundation crevices and take the necessary measures to install adequate insulation.
Roof insulation is a good start for improving your home’s condition. The tell-tale signs that you are losing heat through your roof include:
- Lack of snow on the roof during snowy winters
- Ice dams
- Birds gathering, lured by the heat coming from below
- Damaged or missing shingles
- Leaks
- Condensation
- Peeling paint in your attic
- Steaks of dust on the walls near the ducts
- Cold drafts
- Mold and mildew
- Pest problems
Insulating your roof, walls, doors and windows will reduce heat loss and noise, make the building more solid and durable, decreasing energy consumption and positively affect your bills.
You can choose from various roof insulation options available on the market, taking into consideration their characteristics as well as the particular condition and needs of your roof, such as:
- The type of roof, whether it is flat or sloping
- The inaccessible spaces
- The use of the attic: storage or a living space
- Issues with moisture, ventilation or warmth
- Headroom space in the attic for estimating freedom of movement during installment
You can opt for more traditional insulation types like fiberglass and spray foam or select the more modern type — a radiant barrier insulation.
In cases of difficult roof structures, lack of easy access and serious moisture and condensation issues, we recommend contacting a professional insulation company to assist you with the process.
Always pay attention to the R-value of the insulation material. It is directly connected to the thickness and density and shows how effective the respective option is at keeping heat from leaving or entering your home.
R-value can vary in wide ranges and should be considered depending on the type of climate you live in, and the particular roof problems.
1. Fiberglass
Fiberglass roof insulation can be used in the form of fiberglass batt blankets, blown-in or loose-fill.
Fiberglass batt blanket insulation is produced and cut in advance in sizes to fit the standard ceiling joists and rafters. Because of its lower R-value, in colder climates, it may require the application of several batt blanket layers.
The fiberglass blown-in type is suitable for roofs and attics with difficult access where it is applied using a long flexible tube.
Fiberglass loose-fill comes in bags and can be spread manually filling gaps and joints. You should be aware that fiberglass insulation can lose much of its R-value, due to moistures. See comparing R-values of fiberglass to reflective insulation.
2. Spray Foam Insulation
Spray foam insulation is efficient in beating heat and wind as well as sealing cracks in the roof.
Applied directly to the underside of the roof, it expands and hardens to prevent cold air from entering, heat from escaping and moisture from accumulating.
The open-cell foam insulation variety is soft and flexible, preferred for indoor applications. It is effective for reducing noise levels, for example in areas of low-flying planes or noisy factories.
Closed-cell foam insulation is rigid and is recommended for larger areas, especially when there are moisture problems.
3. Rigid Insulation Boards
Made of dense sheets of closed-cell foam, rigid insulation boards consist of polyiso, extruded polystyrene (XPS), or expanded polystyrene (EPS).
Polyiso type can serve as a radiant barrier due to its foil layer.
XPS has a plastic surface and is blue or pink in color. It is water-resistant but flammable and vulnerable to sunlight damage.
EPS has the lowest R-value but still can be used when the budget is tight.
The three types of rigid insulation boards are suitable for insulating any part of a building, including its roof.
4. Structural Insulation Panels
This insulation type combines a foam center pressed between prefabricated boards. They are available in different shapes and sizes, which makes them suitable for various roof insulation purposes.
5. Radiant Insulations, Including Bubble And Prodex
These two radiant types of insulation consist of highly reflective foil that reduces heat transfer. They are safe and easy to install and their R-value is not affected by humidity.
Bubble Insulation, Bubble Wrap, Foil Only Radiant Barriers and Prodex Total - What's The Difference?
In our expert opinion, radiant barrier insulation is where you get the most bang for your buck. We’ll explain why.
Radiant Barrier Insulation Provides Unmatched Benefits For Roof Insulation
Radiant barrier insulations are also known as reflective insulation systems. Their use leads to the reduction of heat transfer and a lowering of cooling costs.
Air space recommended to optimize performance.
The benefits of radiant barrier insulation include:
- It is not affected by humidity
- It has the ability to block 90 – 97% of radiant heat
- It does not absorb moisture
- It does not emit dangerous substances that can harm your health
- Its R-value does not change over time
- It is thin and lightweight which makes it easy to work with
- It can be used together with other types of roof insulation
Prodex: The Best Choice For Insulating Your Roof Or Attic
For the last 18 years we have sold over 5 billion square feet of insulation to satisfied customers.
We are positive that the best all-in-one solution for insulating your roof is Prodex, because of its ability to beat any insulation problem that may arise in a building.
Prodex can be used alone or in combination with other insulation options.
Made of reflective reinforced foil with high thermal reflectance and low emittance, with a closed-cell polyethylene FOAM center, it is extremely durable and stable.
Under pressure, its micro cells do not collapse and it does not deteriorate over time. Its rippled surface guarantees increased airflow and serves as an efficient vapor barrier.
Its R-value is also not affected by humidity and compression.
Prodex prevents 97% of radiant heat transfer and does not allow condensation that can damage your valuable items or equipment. It is fire-resistant which ensures the safety of your attic and home in general.
It is also lightweight, easy to transport and install and seals perfectly around nails, leaving no chance to any potential leakage.
Prodex Total does not promote mold and mildew. It contributes to the healthy environment of your home or office.
Overall, Prodex is a combination of all insulation benefits in one product: insulation and a radiant, air and vapor barrier. Ultimately, its use as roof insulation increases the energy efficiency and the value of your home.
Yes. The roof is the primary location for heat loss. It accounts for up to 35% of the heat loss in the winter. It’s responsible for virtually all the heat gain in the summer.
Ever wonder why it's so hot in the summer in a house without roof insulation? The radiant heat from the sun passes through the uninsulated roof into the house below. This condition is magnified under metal roofs.
Metal roofs magnify the heat from the sun and the frigid temperatures of the winter. Metal is a very good conductor of heat and cold. In hot weather, metal roofing rapidly transfers the sun's heat into a house. In cold weather, it rapidly transfers the cold in. When a cold surface comes in contact with warm air, it creates moisture on the surface just like a cold can of beer outside in summer. Condensation on a beer can is fine but it’s not what you want in your house.
It’s also bad with tile and clay roofs. These roofs take a little longer to heat up, but once hot, these roofs hold the heat like an oven and continue to transfer the heat into the house even after the sun has set.
To calculate the square footage of insulation required:
Multiply the width times the length of the roof. Then add for your roof slope.
Use 1.1 multiplier for 1:12 to 2:12 slope
Use 1.15 multiplier for 3:12 to 4:12 slope
Use 1.2 multiplier for 5:12 to 6:12 slope.
Example: 30 x 40 roof with 3:12 roof slope.
30 x 40 = 1200 sq. ft. Multiplied by 1.15 = 1380 sq. ft. of insulation required.
- Prevents radiant heat transfer.
- Stops condensation
- R-value not affected by humidity
- Doesn’t allow for nesting of rodents, bugs and birds
- Installs easily
Prodex is a versatile insulation product that does it all - Stops condensation, heat, cold and air, blocks the sound of rain and hail, helps prevent rodents, bugs and birds from nesting. It also doesn’t support fungi like mold and mildew.
The reflective nature of Prodex keeps the temperature consistent on the inside and outside of the roof to prevent condensation. It creates an air barrier that is directly related to the safety of the house in case of fire.
Due to its light weight, it is easy to install, work with and transport, which makes it a preferred insulation for roofs.
Prodex Total has a high-quality core that keeps its shape when exposed to forces. Prodex Total 5M plus has a nominal thickness of 5mm (0.2"). Prodex Total 10M is 10mm (0.4"). Both are closed cell polyethylene foam covered on both sides with reflective reinforced foil facing. Under pressure, the Prodex micro-cells do not collapse -- With a pressure of 6 PSI Prodex compresses just 6%. When the load is relieved, it takes back its initial shape. The density of the foam is between 1.25 lb/ft (sq) - 1.87 lb/ft (sq). This gives the material real body.
Scorching sun, freezing temperatures, blowing winds, or rattling hail? No problem – It’s called Total because Prodex Total does it all.
What are the most popular Prodex Total Insulation for roofs?
WHITE 5M Plus: R15.3
Thickness: 5mm (0.2") closed cell polyethylene foam with reflective reinforced foil on one side and plastic white finish film on the other side. Ideal where white finish is preferred.
