Improving energy efficiency starts in the loft, where choosing the right insulation is vital. In UK homes, there are several options available—from traditional blanket (roll) and loose-fill insulation to more modern methods such as spray foam and foil insulation. Below is an overview of the main types of loft insulation, with technical details, benefits, and links to manufacturer pages supporting each option.
blanket (roll)
Blanket insulation is one of the most common solutions used in UK lofts. Typically made from materials like glass mineral wool or sheep’s wool, these insulation rolls are designed to be installed between joists.
For example, Knauf Insulation Loft Roll 44 is a widely used product. It is made from glass mineral wool, offers excellent thermal performance with a thermal conductivity of 0.044 W/mK, and is classified to Euroclass A1 (non-combustible). Its ECOSE® Technology makes it both efficient and environmentally friendly.
• Knauf Insulation Loft Roll 44
Alternatively, natural fibres are gaining popularity. Thermafleece CosyWool Rolls use British sheep’s wool. They offer breathability, excellent sound absorption, and are fully compliant with UK fire safety standards. This sustainable option appeals to homeowners who want a natural product sourced locally.
• Thermafleece CosyWool Rolls
Loose-Fill and Blown-fibre
Loose-fill insulation is made from lightweight materials such as cellulose, fiberglass, or mineral wool. It is especially useful for topping up existing insulation or filling irregular loft spaces. When installed by professionals using specialist blowing equipment, it is known as blown-fibre. Both methods are highly effective for reaching areas that traditional rolls may leave exposed. Many manufacturers – including Knauf and Rockwool – offer quality loose-fill or blown-fibre products, though specific product links can be found on their respective websites.
Sheet (rigid board)
Sheet insulation comes in rigid boards and is ideal when space is limited or when insulating pitched roofs during loft conversions. Products from leading brands like Kingspan or Celotex offer high thermal performance, a slim profile, and can be precisely cut to fit the contours of your loft or walls.
• More on Kingspan
• More on Celotex
Spray Foam
Spray foam insulation is applied as a liquid that expands to fill gaps, providing excellent air sealing and thermal resistance. While its performance is impressive, there have been concerns in the UK about moisture retention and the potential complications it can present during property surveys. In some cases, surveyors flag spray foam as a risk, which can complicate the process of selling or remortgaging a property. Leading brands in this category include Icynene and Lapolla, though homeowners are increasingly exploring alternatives due to these issues.
Take a look at our spray foam removal services here.
MultiFoil
Foil insulation is a modern, multi-layered solution that works differently to traditional materials. It reflects radiant heat, rather than simply slowing conduction, which means it can help keep your home warmer in winter and cooler in summer—using a slimmer profile that better preserves your loft space.
Two standout products in this range include:
YBS Superquilt
YBS SuperQuilt is a multi-layer reflective foil insulation designed for roofs, walls, and floors. With 19 layers and a thermal resistance of up to 2.50 m²K/W in just a 40mm compressed profile, it combines efficiency with ease of installation.
• View YBS SuperQuilt
Superfoil sf19+
SuperFOIL SF19+ offers a slightly higher thermal resistance of 2.97 m²K/W with a 45mm thickness. Its construction makes it ideal for modern installations where saving space and preventing issues like condensation (and black mould) is paramount.
• Explore SuperFOIL SF19+
Space-Saving Insulation That Delivers: Why Foil Outperforms Thicker Alternatives
In a comparison with 2 other insulation products, foil not only had the highest ease of installation and moisture resistance, it had the hightest space efficency and R value (thermal performance) per milimeter.
Look at the graph below for the results.
For a sleek and modern installation that doesn’t use up your loft space, we suggest foil installations.
Read more about our foil insulation services here.
Get in touch with us today for a free survey and a lifetime guarantee.
Environmental Impact and Sustainability
When choosing loft insulation, it’s worth considering the environmental impact of each material. Many manufacturers now offer eco-friendly options. For example, Thermafleece CosyWool is made from British sheep’s wool, a renewable resource that’s fully recyclable and biodegradable. Glass mineral wool rolls, such as Knauf Loft Roll 44, are often made with a high percentage of recycled glass and use plant-based binders.
Foil also scores well on sustainability. YBS SuperQuilt and SuperFOIL SF19+ are both lightweight, require less material to achieve high performance, and are designed to last for decades, reducing waste over time. Many foil products use recycled aluminium in their construction, further lowering their environmental footprint.
Cost & Value for money
Foil insulation, such as YBS SuperQuilt and SuperFOIL SF19+, may have a higher initial price than basic rolls, but they offer excellent long-term value. These products are designed to last the lifetime of your property, require little to no maintenance, and can help reduce your energy bills year after year. Both YBS and SuperFOIL offer robust warranties, giving you extra peace of mind.
Why Choose Foil Insulation from LoftFoil?
Foil insulation’s ability to reflect radiant heat, combined with its moisture control properties, makes it a particularly attractive option in the UK’s often damp climate. Unlike spray foam—which may trap moisture—and older types prone to sagging over time, foil insulation from LoftFoil is designed to last without losing performance. Its slim profile is especially useful in loft conversions or properties where preserving space is a priority.
LoftFoil specialises in the supply and professional installation of high-performance foil loft insulation products, including YBS SuperQuilt and SuperFOIL SF19+. With these products, homeowners can enjoy reduced heat loss, improved energy efficiency, and a product that meets the latest UK building regulations—all backed by manufacturer certifications and data.
For those interested in a long-term, maintenance-free solution that can also provide peace of mind during a sale or remortgage (since issues like trapped moisture and non-compliant materials are avoided), foil represents a smart, future-proof investment.
In Summary
UK homeowners have several options, each with its own strengths. While traditional materials like blanket rolls, loose-fill, and rigid boards offer affordability and familiarity, modern solutions—particularly foil insulation—present an advanced alternative. With technical advantages such as reflective heat control and built-in moisture barriers, foil insulation is increasingly the preferred choice. If you’re considering an upgrade or new installation, contact LoftFoil to learn how our expert services can help you achieve a more energy-efficient and sustainable home.
