Reflective insulation: what it is and how to install it

How does reflective insulation work?

Reflective insulation is a thermal insulation system made up of one or more layers of aluminium or metallised reflective material —such as aluminium— combined with layers of insulating materials like air bubbles, foam, or insulating fibres.

Its main function is to reflect thermal radiation —up to 95% of incident heat— preventing heat from entering or escaping the building depending on the season. In summer, it reflects the sun’s heat, keeping interiors cooler; in winter, it retains indoor heat, preventing it from escaping.

Unlike traditional insulation materials —such as mineral wool or expanded polystyrene— that reduce heat conduction, reflective insulation acts on infrared radiation. This infrared radiation is the main source of heat transfer that affects indoor comfort and energy use (up to 75% of heat loss or gain in a home).

Types of reflective insulation: single and multilayer

There are two main types of reflective insulation depending on their composition and application: single-layer and multilayer. Thanks to their high thermal performance, light weight, ease of installation, and versatility, both options are perfect for spaces where insulation thickness is limited.

Single-layer reflective insulation

This is the traditional type of reflective insulation. It consists of one aluminium sheet and a layer of bubbles or foam, making it ideal for small home improvements. It’s the lightest, most affordable, and easiest to install solution. It works best for false ceilings or interior walls, though it offers lower insulating capacity than multilayer reflective insulation.

Multilayer reflective insulation

Multilayer reflective insulation improves these features, since it has multiple layers of aluminium mixed with insulating materials like foams, felts, or bubbles, which helps keep heat in and reduce noise.

This type is recommended for roofs and exterior façades. If the intermediate layer consists of air bubbles, it will improve both thermal and acoustic resistance; if it’s made of foam or felt, it will also add rigidity and enhance sound insulation. The main drawback is that it’s more expensive and requires a more complex, demanding installation process.

Advantages and disadvantages of reflective insulation

The key advantages of installing reflective insulation in a home or commercial premises include:

• High thermal efficiency and reflection.
• A thin profile, making it ideal for renovations with limited space.
• Lightweight, flexible, and easy to handle, which allows for quick, practical installation.
• Compatible with other insulation systems and can be combined within a building’s structure.
• Contributes to significant energy savings while improving thermal comfort in homes and commercial spaces.

The main disadvantages associated with reflective insulation are:

• Less effective if installed without an air gap or incorrectly.
• In very cold areas, it may require additional insulation systems. It should be combined with other materials, as it’s not a standalone solution.
• Requires careful installation to avoid thermal leaks. That’s why it’s always best to rely on industry professionals.

Common applications of reflective insulation

Reflective insulation is a versatile material that can be installed in different areas of a home or commercial space, such as roofs and ceilings —especially in attics, false ceilings, and lofts— helping maintain a stable temperature in sun-exposed areas. It can also be used on interior and exterior walls, placed behind drywall or panelling to optimise space.

In full renovations, restorations, or new builds, reflective insulation is ideal for floors and slabs to prevent heat loss to the ground. Ventilated façades are also effective when used to supplement the property’s existing insulation systems. Due to its slim thickness, reflective insulation is an excellent choice for renovation and energy-efficiency upgrades where space is limited.

Installation and best practices

Although the installation process may vary depending on the surface, property type, and specific product used, you should follow these general steps:

1. Prepare the surface. It’s essential to clean and level it properly. The surface must be dry and free of irregularities.
2. Install a support structure, which can be made of metal profiles or wooden battens.
3. Place the reflective sheet and secure it using staples, special adhesive tape, or screws. Leave an air gap between the insulation and the finish layer (2 to 4 cm) to maximise its reflective effect.
4. Seal all joints with aluminium tape to ensure airtightness and prevent thermal bridges.
5. Add the finishing layer (interior or exterior), which could be drywall, wood panels, decorative panels, or other types of cladding.

As always, we recommend hiring a professional installer to ensure optimal and lasting performance of your reflective insulation system.

Reflective insulation is an effective and sustainable solution —an ideal option to enhance thermal comfort in homes and commercial spaces by combining technology and energy efficiency. Its ability to reflect radiant heat makes it a key resource for tackling both cold and heat. This way, it helps reduce dependence on electrical HVAC systems and lower your energy bill.

FAQ about reflective insulation

Does reflective insulation replace rock wool?

Not always. It can complement or replace it depending on the type of insulation required. Rock wool is excellent for acoustic and mass-based thermal insulation, while reflective insulation primarily acts as a radiant barrier, making it more effective in spaces where heat reflection is needed.

How can I tell if my reflective insulation is installed correctly?

It should be tightly stretched, with an air gap of at least 2 cm between the insulation and the surface, no thermal bridges (uninsulated areas), and sealed joints using aluminium tape or a similar material.

Is it suitable for moisture or just temperature?

It’s mainly used for thermal insulation, though some models also act as vapour barriers, helping control humidity. However, it’s not the best option for preventing structural dampness or water infiltration.

Can I install it myself?

It’s relatively easy to install with basic tools. Many reflective insulation products are designed for DIY installation, as long as you follow the manufacturer’s instructions. Still, for best results and maximum efficiency, it’s highly recommended to hire a professional installer.

Is it suitable for extreme climates?

Yes, especially in very hot or warm regions, as it reflects radiant heat. In colder climates, it’s best to combine it with other insulating materials such as mineral wool or polystyrene.

How does it differ from conventional thermal insulation?

The main difference is that reflective insulation is thinner, lighter, and reflects heat. On the other hand, conventional materials (e.g., rock wool or polystyrene) insulate by mass and conductivity. Reflective insulation is also less invasive, taking up less space during home renovations.

Which type should I buy for an older home?

A multilayer reflective insulation system with a vapour barrier and good breathability —combining reflective layers with insulating materials— is the best choice. This composition will enhance thermal comfort without requiring major renovations.