Case Study:

Hybrid Flat Roof

Main Contractor


Project Type

Hybrid Roof Extension

Project Value

House Garden and Patio

The Project

Looking to expand his current home, an extension was needed. A one storey, flat roof extension was the plan and at 27m2 it ensured there would be plenty of new space added to the home.

The Problem

Being a new build extension with a hybrid flat roof, it was vital that Paul achieved a 0.18 U-value to comply with building regulations. This needed to be done without having to increase the overall height of the extension, which other solutions couldn’t achieve.

How We Helped

Talking to the SuperFOIL technical team, Paul was given a solution that achieved his required U-value as well as not adding any height to the extension.

Using a combination of SF40, SFTV and PIR board, Paul managed to achieve a lower U-value of 0.17. The SuperFOIL products used also provided him with a radiant barrier and vapour control layer.

SF40 is a 65mm thick product with an R-rating of 3.47 when used in a roof. As well as providing thermal insulation, it also acts as a vapour control layer and radiant barrier. SF40 provides an airtight finish to any project and is simple to install.

Paul praised the technical team stating that the “technical support was excellent and got building control off our backs”. He also added that the products were “Excellent” and “very easy to use”.

We help 1000's of customers every year

Here are just a few of the comments we've received...

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Loft Conversion

Actually, I bought Superfoil for my small extension and I must say easy to install and it works, room is comfortable better than Kingspan. Now looking at installing an underfloor in my daughter's house. Thanks!

Duncan Walker

Conservatory Conversion

I'm really grateful for all the info you've provided, many thanks. To be honest I didn't think your stuff is as good as it clearly is, and we'll definitely be using it in the future. Can I ask a favour and ask you to calculate two more please?

Carl Bell

Self Build

In the past, I used SF19 for thermal insulation of the roof. I have the best experience. I'm thinking about insulating the house outside wall. As I want to be clear, I will definitely call. Many satisfied customers wish.

Jiri Milfait


We’re delighted with the thermal improvements after fitting Superfoil SF40. The system was clearly and helpfully specified, simple to install and immediately felt warmer, despite this also being the Winter of Beast from the East. It suits our 200 year old house, now heated with a modern, green air source heat pump.

Tim Clements

Senior Building Control Surveyor

Many thanks for all your assistance with this matter, you have been very helpful. The information you have provided has been very useful to one of our customers and I am now more familiar with this type of double fit of SuperFOIL as a suitable method of achieving compliance with The Building Regulations.

Donna Worrell

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