Build Tight & Ventilate Right is the mantra of the Energy Savings Trust, so that's exactly what we offer. MVHR with airtight insulation.
Eliot Warrington, MD & Founder
Multi-layer Foil Insulation
Maximum insulation in the minimum space

If you're looking for a high performance, cost effective, clean, efficient, and easy to fit insulation product, ideal for new build and retrofit projects, the latest multi-layer foil insulation certainly fits the bill. Designed to keep you warm in the winter, it's unique foil properties will also reflect excessive heat during the summer to help keep your building cool.

This story describes what it is, what it does, and why more and more people are choosing to use it.

what is multi-layer foil insulationWhat exactly is multi-layered foil insulation?

Multi-layered foil insulation is a high tech insulator that provides effective and efficient insulation against all types of heat transfer, especially thermal radiation heat transfer. It works by combining multiple layers of thin reflective ‘space blanket’ material, usually plastics coated with aluminium, with foam and wadding in between each layer. By bonding these layers together, the multi-layer ‘quilt’ is thin, lightweight, and forms a highly effective barrier against heat transfer due to conduction, convection and thermal radiation.

what is multi-layer foil insulationFoil insulation - where did it all begin?

During the early days of Space exploration, innovative approaches were needed to tackle new and harsh environmental conditions never before experienced within Earth’s atmosphere.

From the beginning, a major concern to those racing into Space was how to protect spacecraft, equipment, and astronauts from thermal radiation and the extreme temperature fluctuations of space, both extreme heat and extreme cold.

In 1954, NASA invented a lightweight, reflective material now commonly known as a "space blanket" and used it to create a slim multi-layered foil insulation. In 1979 the European Space Agency began using a similar product for their Ariane rockets. The multi-layer foil insulation solution was so successful at maintaining a constant, comfortable temperature for space vehicles and the crew inside, it is still in use today.

what is multi-layer foil insulationWhat are the benefits of multi-layered foil insulation?

'Build tight - ventilate right' is the message coming from the Energy Saving Trust. In other words, to minimise your space heating energy requirements your building envelope needs to be as airtight as possible. Multi-layer foil insulation is the most airtight form of insulation on the market.

Multi-layer foil insulation is lightweight, flexible and VERY EASY to install. While the material costs may be similar to wool or foam board, the overall cost of ‘insulating your property’ often works out far less due to the labour saved during installation. Applied above or below the rafters in a single quilted sheet, very few cuts are required meaning there is also far less wasted material.

Multi-layer foil insulation has an estimated life in excess of 50 years, if not the life of the building, unlike mineral wool which is affected by dust, drafts, pests and moisture and only provides optimum insulation for 10-15 years. This means foil insulation is an extremely ‘green’ option in terms of its product lifecycle carbon footprint. It can easily be reused or recycled if necessary, adding to its useful life.

Multi-layer foil insulation does not rust, rot, corrode or decay and is non-toxic. The enclosed nature of the insulation also means there are no loose, irritant fibres so there is no need for special protective clothing or breathing apparatus when fitting, all of which saves time and money. Foil insulation also reduces dependency on chemical foam products which cause harmful CO2 emissions.

Multi-layer foil insulation provides a very effective barrier against conductive, convective and radiated heat transfer, unlike traditional forms of insulation. Foil’s unique reflective properties not only keep the heat in during winter, it also protects against solar heat gain during the summer which helps to keep the building cool. Foil insulation will therefore save money on heating and air-conditioning costs*.

* To cool a room by 1oC requires ten times more energy that warming it by 1oC. Given the rate of global heating and the need to keep buildings cool in summer, adding an effective heat reflector to your roof represents a sound long-term investment.

what is multi-layer foil insulationHow much space do I need to install it?

Multi-layered foil insulation has an ultra slim profile, which makes it ideal for retrofitting buildings with limited roof space, or where it is desirable to leave original features such as beams or purlins exposed. Independent in-situ tests have shown that foil insulation provides a similar level of insulation as the traditional mineral wool insulation, while occupying less than half the space.

As the Code for Sustainable Homes requires you to add more and more insulation, you can either build a taller roof and thicker walls at the cost of valuable floorspace, or you switch to a slimmer more effective form of insulation.

what is multi-layer foil insulationDoes foil insulation comply with building regulations?

YES, provided it has been tested in an accredited laboratory using the conventional ‘hot box’ test. Such a test will provide a certified ‘R’ value which can be used to calculate the overall ‘U’ value of the entire roof or wall structure.*

The most recent government circular relating to Building Regulations part ‘L’, issued by the Department for Communities & Local Government in June 2009, states “Building Control Bodies (BCBs) and Approved Inspectors are free to make their own judgements about compliance with the regulations”.

To date no local authority has rejected the use of multi-layer foil, although some may require an additional layer of mineral wool or foam board. The safest course of action is to always check with your local BCB before commencing any new development.

* ‘R’ value represents the thermal resistance of individual components. ‘U’ value represents the rate at which heat is lost, and normally refers to the entire structure. For optimum roof insulation for example, you’re looking for the highest possible R value of each roof component, slates, plasterboard or insulation, and the lowest overall U value for the entire roof.