To improve the energy efficiency of your home, roof insulation is one of the best things you can do. Insulating your roof can significantly reduce heat loss, lower energy bills, and improve the comfort of your home year-round.
With various roof insulation types available, it can be difficult to decide which is best suited for your needs. In this article, we’ll explore the different types of roof insulation, their pros and cons, and advise how to choose the right option for your home.
Why does a roof need insulation?
Roof insulation is crucial for maintaining a stable temperature in your home. It acts as a barrier, preventing heat from escaping in the winter and keeping your home cool in the summer.
Without proper insulation, up to 25% of heat can be lost through the roof, leading to higher energy bills. Roof insulation also helps reduce condensation, which can lead to damp, mould and even damage to your property.
Along with energy efficiency, proper roof insulation can increase your home’s value and contribute to a more sustainable living environment by lowering your carbon footprint.
Roof insulation types
When choosing your roof insulation, it’s worth taking the time to check the different types available and how they can benefit your home. Here are some of the pros and cons of common roof insulation types.
Insulation panels
Insulation panels are rigid boards, designed for easy installation. They provide excellent thermal insulation, and are ideal for flat roofs or pitched roofs where space is limited.
Pros:
- High insulation value
- Easy to install
- Lightweight and durable
- Can be used on both flat and pitched roofs
Cons:
- More expensive than other insulation types
- Requires precise cutting for a snug fit
For homeowners looking to insulate their flat roof, Eurocell’s high-quality insulation panels offer a durable and reliable solution.
PIR insulation boards
Polyisocyanurate (PIR) insulation boards provide excellent thermal performance, and can be used for walls, floors, or flat and pitched roofs. The foam board is typically fixed between the joists or can be fitted above the roof deck.
They are similar to insulation panels but often offer higher insulation values per thickness, making them a strong choice for energy efficiency.
Pros:
- High R-value per thickness
- Moisture-resistant
- Long-lasting performance
- Suitable for retrofitting
Cons:
- Higher cost compared to thermal rolls
- May require professional installation
Eurocell’s range of insulation boards provides top-tier performance and durability, perfect for enhancing the energy efficiency in any roofing project.
Loft insulation roll
Loft insulation rolls are a popular and cost-effective option for roof insulation. These rolls are easy to install, making them ideal for DIY projects, and can be used in both pitched and flat roofs.
Pros:
- Affordable
- Easy to handle and install
- Suitable for large areas
- Fire-resistant (if made of mineral wool)
Cons:
- Bulkier than other insulation types
- May require additional layers for higher insulation values
Loft insulation rolls can be a great option for DIY enthusiasts looking to improve their roof’s energy efficiency without professional help.
Insulated plasterboard
Insulated plasterboard is a combination of insulation board and plasterboard, making it a convenient two-in-one solution. It’s ideal for pitched roof spaces where both insulation and a clean interior finish are required.
Pros:
- Combines insulation and a finishing layer
- Saves space
- Easy to install
Cons:
- More expensive than regular plasterboard
- Best suited for pitched roofs
Cost to insulate a roof
The cost of insulating your roof depends on the type of insulation material, the size of your roof, and whether you opt for professional installation.
The initial investment might seem high, but the long-term savings on energy bills can make roof insulation a cost-effective choice. Also, properly insulated roofs help to increase the lifespan of your roofing system by reducing wear and tear caused by temperature changes.
Is insulation roll or board better?
Choosing between insulation roll and board depends on the aim of your project. If you’re looking for a cost-effective, easy-to-install option, thermal insulation rolls are a great choice.
However, if you want to achieve the highest possible insulation value or insulate a flat roof, insulation boards or panels may be more suitable. For a detailed comparison of flat roof options, check out our recent guide: ‘Flat Roof vs Pitched Roof: Pros and Cons’
How to insulate a roof
Roof insulation can be installed in a few different ways, depending on your roof type. For flat roofs, insulation panels or boards are typically laid above or below the roofing membrane. For pitched roofs, insulation rolls can be placed between the rafters, and insulated plasterboard can be applied directly to the underside of the roof structure.
Ventilation is also key otherwise moisture can build up damaging both the roof and insulation. It can also lead to condensation and damp. When insulating your roof, install vents like soffits, which are designed to let air flow. Make sure that you don’t block any existing vents too. Another method is leaving a 50mm gap between the joists and insulation.
There’s also the R-value to consider. This measures how well the insulation blocks heat passing through it. So, if your R-value is high, it means your insulation is working well because heat is having trouble escaping. A good R-value for UK homes is 4.54m²/K/W. To get there, choose thick insulation products or layer it to build the thickness.
For new builds, the U-value for roof insulation should be a minimum of 0.16 W/m2K under Building Regulations. This is another measure that tests heat loss through the roof but unlike the R-value, a lower U-value is better because it means the roof is more energy efficient. Again, opting for thick insulation will help lower your roof’s U-value and hiring a professional to fit it correctly.
Should there be a gap between the insulation and roof?
In most cases, it’s recommended to leave a small air gap between the roof and the insulation to allow for ventilation. This helps prevent condensation, which can lead to mould build up and structural damage.
Which roof insulation material is best?
The best roof insulation material depends on your specific requirements, whether it’s cost, ease of installation, or insulation value. If you’re looking for an affordable solution, thermal insulation rolls are a great option. However, if you want to maximise insulation performance and longevity, insulation boards or panels tend to offer better results.
Choosing the right roof insulation can significantly impact your home's energy efficiency, comfort, and overall durability. Whether you opt for insulation panels, boards, or rolls, investing in quality materials is key to long-term savings. To find the perfect insulation solution, explore Eurocell's full range of roofing insulation products. Contact us today to learn more.