Built Up Metal Roof
Knauf Insulation Built Up Metal Roof insulation Glass Mineral Wool


Our mineral wool insulation solutions for built-up metal roofs provide excellent levels of sound absorption, reducing the drumming effect of rainwater and improving the overall acoustic performance of the roof.

Systems typically consist of a low profile metal inner liner sheet, separated from an outer, higher profile metal weather sheet and are typically assembled on site. The cavity between them is filled with a layer of insulation to provide the specified level of thermal performance.



Why Mineral Wool?

  • Mineral wool reduces the drumming effect of rainwater on lightweight roofs and significantly improves acoustic performance.

  • Mineral wool rolls knit together at joints, reducing the potential for unwanted loss of thermal and acoustic performance.

Download our Solutions Guide   Download our Built-up Metal Roofs PDF

Typical U-values
Using Earthwool FactoryClad 32

Earthwool FactoryClad Roll Thickness (mm)Rails at 1.20m spacings
160 (2 x 80)0.24

NOTE: Knauf Insulation recommend that the roof system designer / manufacturer is contacted for U-values specific to their systems.

Typical U-values
Using Earthwool Factoryclad 40

Earthwool FactoryClad Roll Thickness (mm)Rails at 1.20m Spacings
240 (2 x 120)0.19

NOTE: Knauf Insulation recommend that the roof system designer / manufacturer is contacted for U-values specific to their systems.

These U-values are taken from default values in the BRE U-value calculator using twin-skin metal panel-rail and bracket system as examples only.

To ensure an accurate U-value calculation, the roof or wall manufacturer should be contacted for the U-value specific to the system and associated components being used.

For any U-value calculations for alternative construction build-ups, please contact our Technical Support Team on 01744 766666.
For written U-value calculations, please complete our contact form by clicking here, including details of your full through construction build-up and we will respond accordingly to meet your requirements.
We are a fully accredited member of the industry leading British Board of Agrément (BBA) U-value and Condensation Calculation Competency Scheme which promotes and assists accurate, objective and consistent calculations of U-values and condensation calculations within the UK construction industry. As part of our ongoing participation in the scheme, we are required to maintain written records for audit trail purposes.