U-VALUE CALCULATOR
SuperFOIL products applied on pitched roof over rafters

OVER RAFTER
APPLICATONS

When insulating over your rafters it’s essential that your chosen products won’t pose a condensation risk. SuperFOIL’s Breathable products are W1 watertight, provide high levels of moisture protection, breathable properties, and more; all in a product that can be installed up to twice as fast as traditional insulation types.

Application Instructions

SuperFOIL Installation

Start at the bottom of the roof, at the eaves support tray/guttering. Ensure the SuperFOIL is properly aligned with the edge of the roof, then secure it by stapling the start of the roll to your rafter.

Once secured, you can begin to unroll the product out horizontally across the rafters.

As you go, it’s important to properly fix your insulation in place and to fully seal all joints, tears, and cuts using SuperFOIL Multifoil tape to ensure an airtight finish. Refer to the Full Installation Guide for specific guidance on how to properly cut, fix, and seal SuperFOIL products.

If you are using counter battens before installing your tile battens, which we highly encourage, then you should ensure that the insulation is pulled taut whilst being fixed into place to ensure the product doesn’t drape between the rafters.

Alternatively, if you decide to apply the tile battens directly to the insulation layer, you need to ensure that the product is draped between the rafters to create a 10mm gap (at least) under the tile battens to allow water run-off.

For a more comprehensive guide to properly installing SuperFOIL products in an over rafter application, we’d encourage you to download our complete installation guide, for free, by clicking the button below.

Best Products for External Application

Choose your Ideal Solution

Use the charts below to find the ideal solution for your project

SELECT VARIABLE

THERMAL PERFORMANCE
PRODUCT DIMENSIONS
ESSENTIAL CHARACTERISTICS
PRODUCT COMPOSITION
Specification SF19BB SF40BB
Core performance 1.45 R Value 2.85 R Value
Roof Performance* 2.03 R Value 3.47 R Value
Wall Performance* 2.24 R Value 3.69 R Value
Emittance 0.19 / 0.05 0.19 / 0.05

*Core value + 2 air spaces / EN 16012

Specification SF19BB SF40BB
Thickness 40mm 75mm
Length 10m 10m
Width 1.2 / 1.5m 1.5m
Coverage 12 / 15m² 15m²
Weight 8 / 10kg 20kg
Specification SF19BB SF40BB
Reaction To Fire (Euroclass) Class F Class F
Water Vapour Resistance 0.115 MNs/g 0.115 MNs/g
Resistance To Water Penetration W1 W1
Tensile Properties (Length) 135/13N/50mm 135/13N/50mm
Tensile Properties (Width) 85/20N/50mm 85/20N/50mm
Resistance to Tearing (Length) 110N 110N
Resistance to Tearing (Width) 120N 120N
Elongation (Length) 70 / 3% 70 / 3%
Elongation (Width) 60 / 5% 60 / 5%
Flexibility at Low Temp. -40°C -40°C
Specification SF19BB SF40BB
Reflective Coated Breather Membrane 1 1
Perforated Aluminium Coated Reflective Foil PET 3 8
Perforated Reinforced Heavy Outer Reflective Foil 1 1
Loft Quilt 80g/sqm Layers 4 9
Total Layers 9 19

FREE Insulation Guide

Take advantage of our free insulation guide; an in-depth look into everything you need to know for insulating your project.

Request Free Insulation Guide

This field is hidden when viewing the form
Name
Marketing Consent(Required)
This field is hidden when viewing the form
This field is hidden when viewing the form
This field is hidden when viewing the form
This field is hidden when viewing the form
This field is for validation purposes and should be left unchanged.

Multi-Award Winning Family Business

22960

Before you go, be sure to

Download Your FREE

INSULATION GUIDE

22961
22962
22963