E-therm for Metal Roofs

Pitched Metal Roofs

E-therm is great for metal roofs as it replaces heavy duty foils as well as thermal and acoustic bulk insulation that is normally used to achieve your desired thermal and acoustic performance. E-therm is easily installed creating a vapour barrier, providing thermal insulation and achieving high acoustic values, reducing road, aircraft and outside noise, in the one application.


E-therm comes in different widths and thicknesses to meet your building needs. E-therm also incorporates a 150mm foil flap on the longitudinal side of the product that can eliminate taping or overlapping in most installations. This saves time and money during installation and ensures a vapour barrier that doesn’t rely on tape for it to work.

  1. Starting at the back of the gutter, roll E-therm insulation across the roof rafters/purlins or battens ensuring that the Anti-Glare face is facing towards you during installation.
  2. If you are installing directly over purlins or battens ensure that you can achieve the desired sag between the purlins or battens as this affects the thermal performance of the system.
  3. When adjoining the next roll, make sure that the 150mm foil flap overlaps the first roll. This should ensure that the product is creating a vapour barrier.
  4. NOTE: Only if installing over rafters. Secure to rafters if needed for ease of installation, then fix the battens making sure all rolls are tightly butted. Where necessary tape is to be used. Make sure when fixing battens that they affix as per roof cover requirements and to applicable standards.
  5. All end joins should be taped with Thermotec’s recommended E-therm 75mm reinforced aluminium tape or alternatively overlapped by rafter spacing.
  6. Where necessary cut E-therm around any penetrations making sure a tight fit to minimise openings.


Thermal Performance Table 
Product Required Air Space Ventilation Summer Value Winter Value Design Drawing
E-therm 8mm AG 40mm Nominal Yes R 2.8 R 1.3 DD002 
E-therm 8mm AG 40mm Nominal No R 2.6 R 1.5 DD002
E-therm 5mm AG 40mm Nominal Yes R 2.7 R 1.2 DD002
E-therm 5mm AG 40mm Nominal No R 2.5 R 1.4 DD002