When deciding on specifications, there are lots of questions that tend to pop up, so we've compiled this handy list of FAQ's so you can get answers, fast.

General Enquiries

How does SuperFOIL compare to other foil insulation?

Superfoil is the leading manufacturer of Multifoil insulation on the market. We have produced the world’s highest performing multifoil insulation in SF60, and also the highest performing breathable multifoil range with our ‘BB’ range. 

We have a wide range of distributors based over the UK, Ireland & Europe, meaning that SuperFOIL is always available when you need it.  

Test the quality for yourself with our free sample!

Is SuperFOIL tested and certified?

You can have peace of mind when using any of the SuperFOIL ranges, knowing they have been rigorously tested to ensure they meet the high, reliable standard that you require!

The SuperFOIL range has been tested and certified by BBA ( British Board of Agrément) to BS EN ISO 12667, ISO 8301. Our product ranges are certified to comply with UK, EU & CE regulations by highly respected groups such as BBA, LABC, DIBt & ZAG.

All of our products are independently tested by certified third party labs & notified bodies to ensure the highest of quality.

Are SuperFOIL products airtight?

The majority of our products ( excluding the breathable insulation, for obvious reasons!) are completely airtight when installation has been carried out correctly.  By ensuring your product is airtight you are increasing your insulation performance and getting rid of those nasty drafts. In the long term, this will give you savings on your energy bills!

What is the minimum insulation standard I need to achieve?

The answer to this will be dependant on the project you are working on. Your Building Control Officer will always advise you of what U-value you will need to achieve.  Here is a list of the current building regulations

 Once you know your required U-value, our team of experts are always on hand to work out a personalised, free of charge solution to fit your needs

Can SuperFOIL be used with other insulation products?/Can it be added to my existing insulation?

Yes! SuperFOIL is a highly versatile product and can be used in combination with all other forms of insulation. By adding SuperFOIL to the mix, you are ensuring you have a high performance insulation which will save you money on your energy bills.

Where can I install SuperFOIL?

SuperFOIL products can be installed in a variety of locations -  Our ranges can be used to install within floors,walls and roofs ( both under and over rafters). They can be used in both new build or retrofit projects. 

However, the use of our products has spread far and wide from camper van installations to a record breaking hot air balloon! ( Yes, really! Check it out here)

Will SuperFOIL cause condensation issues within my home?

Absolutely not! SuperFOIL is designed to prevent condensation from building within your insulation. Our ranges of insulation will either provide you with a vapour control layer or a breathable membrane depending on the placement of the insulation. 

Vapour control layers are placed internally and will stop warm air within the home from entering into the layers of insulation. Breathable membranes are placed externally to your insulation, allowing any build up of moisture to escape from the fabric of your build.

Why do I need to install SuperFOIL insulation with an air space?

By installing SuperFOIL with an air space, you are allowing the heat to be converted into ‘ radiant energy’.  Because SuperFOIL reflects 97% of this energy, it means that you will benefit from energy that is usually wasted. What this means for you is that your home will stay cooler in the summer and warmer in the winter.

You do a specialised fire rated range, does that mean your other products are dangerous?

Not at all! We don’t believe in cutting corners here at SuperFOIL.

All of our standard SuperFOIL products comply with UK building regulations for residential use, with a fire rating of ‘E’ when installed behind plasterboard

Our fire rated range offer enhanced protection and added peace of mind. The ‘ FR’ range achieve class ‘0’ for BS 476. Our SFNC has achieved the highest possible Euroclass rating of ‘A1, non-combustible’ and is typically designed for use in high rise buildings and for commercial use.

Which side of the insulation points towards the outside of my project?

This is dependant on the product purchased.

  • For SF19/19+/40/60/ SFTV, FR & SFBA MP it does not matter which way the product is placed - some people typically will install the branded side facing outwards.
  • For SF19BB/40BB & SFTV1L you should install the product with the “dull” side facing towards the outside of your project.
  • For SFBB, the silver/grey side should face the outside of the project
  • With SFUF, the clear, polyethylene layer should be placed facing away from the floor
Will installing SuperFOIL affect my TV/Mobile phone signal?

Television and mobile phone signals vary from location to location. In some instances, this signal may be affected by the use of a reflective foil insulation, however it is important to know that these signals would never be fully blocked due to the windows in your home letting cellular signals through. 

Here at SuperFOIL we would always recommend that if you do experience a weak signal and are wanting to use a multifoil product, to make sure that you place your antenna outside of the ‘insulation envelope’.

Roof Installations

Can I install SuperFOIL above rafters?

Yes you can! All SuperFOIL products can be placed over or under the rafters depending on the needs of your project. 

We have even designed a fully breathable range of products designed specifically for this purpose! SuperFOIL SF19BB and SF40BB are a fully breathable & high performance insulation, meaning that you only have to install one product !

Can SuperFOIL be used in a flat roof system?

Yes! SuperFOIL can be used in flat roofs and well as pitched roofs. Our expert team can help you find the ideal solution to suit your roof. We can also provide you with approved U-value calculations and condensation risk analysis..

Do I need to ventilate my rafters when using SuperFOIL?

Ventilation within a rafter voice is typically not required if you have a breathable membrane (or SF19BB or SF40BB) installed above the rafters.  However, if the rafters have a non breathable felt (often the case in older roofs), you are likely to need a ventilated gap below the felt to allow moisture to escape. 

You should always confirm your proposed plans with your building control authority as they will be able to advise you on the safest design details for your roof. 

Can I cut SuperFOIL into strips and install between my rafters?

We do not recommend using this installation method with SuperFOIL products as it would severely reduce the performance of the insulation.

SuperFOIL is designed to be installed as a continuous layer on the face of the timbers. This is to allow for the greatest performance whilst keeping it quick and hassle free to install!

What size battens do I need to use with SuperFOIL?

This depends on which SuperFOIL product is being used. 


  • SF19 & SF19+ require a minimum batten depth of 25mm
  • SF40 requires a minimum batten depth of 38mm
  • SF60 requires a minimum batten depth of 60mm
  • SF19BB should be counter battened with a minimum batten depth of 38mm
  • SF40BB should be counter battened with a minimum batten depth of 50mm

Wall Installations

What type of wall can SuperFOIL be installed on?

SuperFOIL can be installed in any wall type, whether solid or cavity. Our handy application guides will show you just how simple SuperFOIL really is to install!

Does SuperFOIL reduce outside noises?

Yes! SuperFOIL products offer sound insulation benefits as well as thermal. This is due to two reasons. When installing SuperFOIL you will be improving air tightness within the property which will help in reducing airborne noises. On top of this, the wadding insulation will help with reducing high frequency sounds. 

We are currently looking into specific testing for sound insulation properties on our range of products.

Can SuperFOIL be used for external wall insulation (EWI)?

Absolutely! Our range of multifoils can be used externally, however we would typically recommend our breathable products such as SF19BB or SF40BB. This is because the ‘BB’ products provide both insulation and a breather membrane in one layer, helping to reduce the overall build up.

Can SuperFOIL be used externally on walls over 18m?

SFNC has been designed specifically for this purpose. It is a non-combustible insulation suitable for external cladding systems on buildings over 18m.

SFNC has been used on multiple large scale projects, including the Royal Papworth Hospital.

Can SuperFOIL achieve building reg requirements by itself?

SF19+,SF40 & SF60 can all achieve or exceed the typically required, retrofit rating, of 0.28U on a wall with no other insulation required. 

SF60 can even achieve the new build regulations of 0.18U in a wall with no other insulation.

SF60 is the only multifoil insulation on the market that can achieve this high standard with the use of no other insulation.

Do I need to install a VCL behind the plasterboard if I use SF40 within my wall?

When using SF19, SF19+, SF40 and SF60 there is no need to use a separate VCL. This is because the outer layers of these products are designed to be a high performance vapour barrier with a resistance of 1200 MNs/g.  When installed to recommendations, our product will vastly outperform the majority of standard VCL materials.

Floor Installations

Can SuperFOIL be used under a liquid screed?

SuperFOIL SFUF has been designed specifically for this purpose! The top layer of SFUF is made from polythene which protects the insulation from the screed.

Do i need edge insulation when using SFUF?

When installing SFUF, we recommend that it is lapped up the wall to help tank the floor. This will also provide some expansion room. 

For small rooms this may be adequate, however for larger rooms we would recommend the use of both SFUF & edge insulation.

Can SFUF be used directly under underlay and carpet?

SFUF is suitable for use directly under carpet and underlay. However, we would always recommend a test area to ensure you are happy with how it feels underfoot, due to SFUF not being a solid product.

Can I use multiple layers of SFUF?

Yes, SFUF can be used in multiple layers, although we do recommend keeping it to 1 or two layers.

If you need to use multiple layers to meet your insulation needs, the best method would be to create a ‘sandwich’ by layering SFUF with traditional insulation such as PIR.

Can SuperFOIL be used with underfloor heating?

Yes! SuperFOIL products are safe to use with all underfloor heating systems. 

SFUF was designed for this exact purpose for solid floor constructions!