All you need to know about foil insulation

Though the insulation market today is flooded with many options for insulating roofs and walls, rock wool or fibreglass insulation is what generally comes to mind when we think of roof insulation materials. They are cost-effective and offer good thermal and acoustic insulation. In this blog, however, we will be discussing foil insulation. An often overlooked yet highly effective roof and wall insulation solution.

What is multifoil insulation?

Multifoil insulation, multifoils or foil insulation consists of many thin reflecting layers of foil alternating between layers of insulating sections of thermo-foam and polypropylene - commonly called wadding. The layers of foil and wadding together work to improve the thermal performance in your facility. Multifoil insulation is used in new construction as well as in refurbishment projects. 

How does foil insulation work?

The transfer of heat through materials happens either by conduction, convection or radiation. The low emissivity outer layers of the foil insulation rolls reflect up to 95% radiant heat back into the building. As a result, it prevents the conditioned air from sneaking out. On the other hand, wadding minimises heat loss by conduction and convection. This combined action of foil insulation is what makes it stand out. 

Is foil insulation better than traditional insulation?

Multifoil insulation is a step up compared to other traditional insulation available on the market today. While rock wool insulation and most other insulation products restrict heat transfer only through conduction or convection, foil insulation limits the flow of heat through all three mechanisms.

Unlike rock wool or fibreglass insulation, the  foil insulation rolls do not give out any irritating fibres. The fibres released by the wool insulation are known to cause skin irritation and other respiratory problems. With  foil insulation, you need not trouble yourselves with masks. It also improves indoor air quality as no fibres are released into the environment when plasterboards are removed.

Insulation boards, rock wool or glass wool insulation effectively prevent heat loss but have no control over airflow or water vapour. Foil insulation blanket, on the other hand, regulates both air and vapour circulation through its fabric. It also acts as a thermal barrier that reduces cold bridging when laid across rafters or timber studs.

Thermal performance of foil insulation:

The performance of any insulation material is measured in terms of its R-Value. R-value indicates how well an insulating material resists heat flow. Higher R-values usually mean better insulating properties. The R- values of any insulation depends on the insulation itself, its thickness, the application, moisture and many other factors. 

Multifoil insulation makes use of the static air that surrounds it. The heat is thrown back by the reflective layers of the foil insulation. Since air is a good insulator, the total R-value includes the core value of the multifoil, plus the value of one or two adjacent air gaps. Multifoils have proven to perform well in industry tests.

For roof refurb/extension jobs in the UK, you have to achieve a U-value of approximately 0.18. Using multifoils this target is quite easily reachable. Foil insulation will help achieve the required U-value when used in combination with other insulating products. 

Why use foil insulation?

We lose about 30% of the heat in our home through the roof and 25% through walls on average. Multifoil insulation effectively stops heat loss in roofs and walls. Multifoils allow you to keep your home comfortably warm, even when it is freezing outside. Some other benefits of foil insulation include: 

Foil insulation provides effective insulation all year round:

Foil insulation works brilliantly, irrespective of the season. If the roof in your building is exposed to direct sunlight, temperatures will increase throughout your facility. The increasing temperature can be quite uncomfortable, especially without air conditioning. When foil insulation is specifically used in such cases, it acts as a barrier, reflecting a large portion of the heat away from your living space. As a result, it can keep your home or workspace cooler in the summer months. The use of foil insulation reduces energy expenses by limiting air conditioning usage during peak times.

In winters, it retains heat by reflecting heat indoors whilst limiting heat loss through the roof or walls.

Foil insulation saves energy:

Since the multiple layer foil insulation limits heat loss by all three mechanisms, it is an excellent way to save both money and energy. 

Foil insulation is high performing product:

The foil blanket is high-performing insulation that reflects heat to the source. With foil insulation rolls, you’ll achieve the same levels of efficiency in a considerably smaller profile as compared to traditional insulation products. Although it is about 3 to 5 times thinner than mineral wool rolls or slabs, it is just as effective, if not more.

Ease of installation:

The foil insulation rolls are light in weight and can be installed with staples, quite easily. They can effectively cover the irregular areas and rough edges in the roofs or walls. They are ideal to work with, especially if you need to install insulation in areas with space constraints like a small attic space. They do not need any specialised tools or equipment to be installed. 

Foil insulation can insulate almost anything!

Apart from insulating roofs, foil-insulation blankets can also be used to insulate walls and floors as well. As effective as they are, in reflecting heat that enters your facility through the roof, they are just as effective in reflecting heat to the source when used for wall insulation or floor insulation. They help to achieve lower U-values when used in combination with other insulation products. 

Foil insulation saves space and is durable:

Traditional insulation like mineral wool insulation slabs or PIR boards, are quite thick and consume a considerable amount of space. You will not face this issue with multifoils. The foil insulation blanket is a very light and thin product that saves space. As a result, you will have more indoor space when they are used to insulate walls. It is especially used in loft conversions, wherein the space constraint exists.

You need your new insulation to endure as long as possible when you install it. Foil insulation could give you the best ROI. Multifoil insulation has a longer life expectancy than many other types of insulation, allowing you to get the most value for your money. You can achieve the best results with foil insulation, and it's worth investing in a high-quality device whose energy savings will soon pay for themselves.

Multifoil insulation is environmentally friendly and meets building regulations!

With the UK gearing up to meet its carbon neutrality goal by 2050, the construction industry is looking into new, greener, cleaner insulation products and standards. Multifoil insulation takes you one step closer to this end goal. Most foil insulation blankets are made using recycled materials. They are almost completely biodegradable at the end of their service life, making them nature-friendly options. 

The Superfoil and Actis insulation products that we store at Buy Insulation Online are LABC Registered System approved. The products assure quality and meet the standards required by insulation products

Multifoil insulation we store here at buy insulation online include: 

Superfoil SF19+ Foil Insulation Roll: SuperFoil SF19+ is high-performance, multifoil insulation that offers exceptional thermal insulation all year round. A single foil insulation roll performs three functions: It acts as an effective vapour barrier, a radiation barrier and provides efficient insulation. 

The foil insulation blanket makes use of Dupont's ultra-efficient nano-coating technology. It adheres to building regulations making it ideal for use in all projects, including new construction, extensions and retrofits. The easy-to-install foil insulation roll effectively prevents air leaks and draughts. 

Actis Hybris Multifoil Insulation Panel: All year long, Actis Hybris foil insulation provides excellent thermal and acoustic insulation in your facilities. It's made from curved polyethene foams attached to aluminium-coated polyethene foils in a honeycomb structure. Its unique construction includes multiple low emissivity cavities, thus enabling the product to give an exceptional thermal performance. They do not sag over time or have irritating fibres that affect the indoor air. For this reason, they are an upgrade when compared to traditional wool insulation

The foil insulation blankets reduce thermal bridging. They are wind and moisture resistant. Foil insulation is light, portable, and quick to install. It is ideal for roof insulation and can be used in all new builds and retrofits. 

Actis Hybris Boost R Hybrid for roof and wall: The Actis Boost R Hybrid membrane can be used to insulate roofs and walls. It combines two advantages into one, easy-to-use product. A built-in breather membrane in the foil insulation allows for superior thermal performance. The long-lasting insulation minimises thermal bridging. The dual features of Boost R Wall foil insulation allow for a reduction in the number of installation processes while maintaining the same needed U-value by lowering the thickness. It can also be used in conjunction with other insulation products

Actis Hcontrol Hybrid Foil insulation: Actis Hcontrol Hybrid blends two advantages into a single outstanding product. A built-in vapour controller in the multifoil insulation offers the product unrivalled thermal performance all year long. It adheres to the building regulations and can be used together with other insulating materials. 

Hcontrol Hybrid foil insulation roll's dual efficiency allows for a reduction in installation steps whilst saving space. It maintains the same required U-value by decreasing the thickness of the insulation.

Actis Triso 10plus foil insulation panel: Triso-Super 10+ is a light insulating product that provides optimum thermal efficiency and saves Actis triso 10plusspace while remaining thin. The foil insulation is airtight, watertight, and resistant to vapour. It works as a barrier against cold air intrusion while also keeping warm air in. 

Foil insulation with a thickness of 35mm gives the same thermal performance as that of a 210mm thick mineral wool. Unlike wool insulation slabs, the foil insulation does not emit any fibres or irritants into the air, improving internal air quality.

Foil insulation is easy to cut, transport, and install. It ensures minimal onsite waste, and installation requires no special tools. Foil insulation aids in achieving the highest finish and lasts the life of the structure.

Is multifoil insulation a DIY project ?

With multifoil insulation, insulating roofs is just a two-person job. To insulate an attic, first off, you need to gather some tools like the foil insulation rolls, a sharp pair of scissors, staples and electric stapler gun, and aluminium foil tapes

How to insulate rafters with multifoil?

Starting at the top of the roof, roll the multifoil horizontally along the rafters. Secure the foil in position with staples, placing staples using an electric staple gun at every 100 mm. Once you reach the other end of the roof, cut the foil and seal it using foil tape or you can pre-cut the foil insulation roll to size. Any extra layers of foil should overlap by at least 75 centimetres. All overlaps and joints must be further secured using foil tape.

To complete the installation, cut the foil insulation along the rafters. Staple it straight onto the wall plate after carefully positioning it into the eaves to form an insulation blanket that covers the entire roof. 

In conclusion :

Multifoil insulation is a step up from the traditional insulation methods. The initial investment might be a bit higher but when compared to labour charges and other charges relating to the installation of insulation boards or slabs, foil insulation like a much better option. 

For high-performing foil insulation rolls and panels visit Not only do we supply you with top-quality pipe insulation, duct wrap, acoustic insulation products, but we also plant three trees per order, making your almost carbon Positive!


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