SF40 – UK’s top performing multi-layer foil insulation

LABC Registered System Approval for U-values From 0.14

  • Pitched Roof


  • Wall


  • Flat Roof


  • LABC Registered System Approval
  • Maximum insulation, minimum space
  • Lightweight, flexible & easy to install
  • U-value solutions as low as 0.1
  • Ideal for new build or retrofit
  • Fits over or under rafter
  • Made from 40% recycled materials

SF40 – Multi Layer Foil Insulation

SF40 is SuperFOIL‘s EXTRA performance multifoil insulation. Extremely cost effective with a 68% increase in performance over our standard multifoil. SF40 beats any multifoil competitor products R value, guaranteed!

With a mission to build a better multifoil insulation SF40 combines the technical innovation of 55 layers and is configured for maximum efficiency, achieving higher values than previously thought possible within the industry. The enhanced thickness combined with radiant reflective properties and air barrier properties provide benefits over traditional (non reflective) open face insulation like glass fibre. SF40 includes CE certified vapor and water barrier outer layers.

SuperFOIL SF40 maximises roof and wall insulation with efficient use of space. SuperFOIL also has the strongest multifoil material aiding installation and reducing waste. LABC registered detail makes Building Regulations simple.

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Key Features

  • BBA Tested R value of 3.58 in roofs & 4.04 in walls
  • SF40 is LABC Registered System approved
  • CE certified for its performance as a vapour and water barrier
  • Fully woven outer foil layers make SuperFOIL the strongest multifoil material further aiding installation and reducing waste
  • Manufactured with 40% recycled materials and is recyclable at the end of its useful life
  • Non hazardous with no special requirements for installation or disposal of waste
  • “COMBI” installation methods allow use with any other form of insulation insulation
  • SF40 has been tested to BS EN 12667, ISO8301 by BBA a UKAS Accredited laboratory
  • Can be used in Roof, Walls & Floors for both New build and retrofit applications

European Technical Approval (ETA)

The EU has proposed under ECPD 1989 OJ L106/1 a new technical standard is to be developed that will incorporate the full performance of multi layer foils under real conditions including radiant reflective properties and air seal properties. This will ultimately result in a new CE or ETA classification.

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Technical Information



Polypropylene reinforced heavy outer laminated foil
Aluminium coated reflective foil PET layers
Thermo foam sepatation layers
Loft quilt 80g/sqm layers
Total layers
142 poly tube



Pitched Roof ‘R’ value
Flat Roof ‘R’ value
Wall ‘R’ value
Thickness installed
Weight per roll
Dimensions packed
1.5m x 580mm
Roll dimensions
1.5m x 10m
Total area per roll
15 sqm

Installation Guide

Under or Over Rafter

click here for our full install guide

Apply SuperFOIL directly to the rafters from the roll either horizontally or vertically.

For over rafter start at the bottom and work up the roof overlapping at each junction. For under rafter start at the high point and work down, overlapping at each junction as you add the layers.

When installing vertically start at the high point and roll down the rafter.

Apply tension to the SuperFOIL as you staple in place; staple into the rafters with staples inserted at regular intervals, 50mm to 100mm spacing is recommended. Cut to length and fix the next layer.

Overlap all joints by a minimum of 50mm and staple onto the rafters where the joint crosses the rafter. Seal all joints using SuperFOIL tape.

At the eaves trim SuperFOIL around the rafters and seal to either the wall plate or the Cavity wall insulation if present.

To fix plasterboard when using SuperFOIL under rafters. Install battens sized according to the product used (SF19 = 25mm); at right angles to the rafters. Always apply battens around window reveals.

Apply tape to any tears, cuts or joints before fixing plasterboard to the battens.

For walls

Fix vertical battens to the wall appropriate to the material being used. Position the SuperFOIL across the wall horizontally and staple to the face of the battens stapling at 50 to 100mm centres.

Repeat for each layer as needed overlapping by at least 50mm with each layer. Trim as required and staple and tape all joints.

Batten around window reveal perimeters with battens and secure the SuperFOIL to them. Then fix a counter batten horizontally and finally fix the plaster board to this batten.

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