Thermostable diffusion membranes for metal roofs.
Long-term reliability and safety of your home with a 20-year warranty. 

DELTA®-THERM PLUS / DELTA®-THERM membranes are specially designed by our company for use with metal coatings, under which the thermal load on the under-roof membrane is higher than, for example, under mineral tiles or bituminous tiles. These heat-resistant membranes have significantly higher resistance to thermo-oxidative aging (accelerated aging test 90 days at +150 ° C) compared to conventional polyethylene and polypropylene membranes (90 days at +70 ° C). This is achieved by using a unique functional acrylic layer and a durable polyester base. 

DELTA®-THERM PLUS / DELTA®-THERM with “lotus effect”: the surface is formed by a smooth acrylic functional layer that has excellent water repellency and ensures reliable removal of even more condensation. Condensation constantly forms on the back of metal roofs, especially on cold nights and early morning. 

DELTA®-THERM PLUS / DELTA®-THERM meets the requirements of the European fire class B-s1, d0 and therefore is fireproof. This is the highest fire safety class for building polymer materials. With our new membranes, you protect your home for years to come. 

Their anti-blend coating prevents annoying reflections even in bright sunlight, which means that roofers can work more comfortably and roof your home with guaranteed quality. 

Due to their high tensile strength, these diffusion membranes can be installed on solid flooring as well as on rafters and insulation. Membranes can be used on both insulated and cold roofs. 

DELTA®-THERM PLUS / DELTA®-THERM are UV resistant for up to four months (5000 hours of QUV testing compared to conventional membranes, which are tested for only 336 hours) and thus ensure the highest possible safety even in the event of unplanned construction delays due to problems with the supply of roofing, design changes and other unforeseen reasons. 

DELTA®-THERM PLUS has integrated adhesive zones on both edges of the web for faster and more secure installation, so that the penetration of water or cold air through the overlaps is excluded and the thermal insulation is always protected.

Overview of the most important advantages

Temperature resistant up to 150 ° C for long-term roof protection.

The water-repellent surface allows condensation to drain quickly.

Fire class B-s1, d0 and UV resistance up to 4 months.

The quality of the membrane is confirmed by a 20-year waterproof guarantee.

Installation of DELTA® – THERM PLUS / DELTA® – THERM


Roof membrane for use in extreme conditions

The thermostable underlay membrane DELTA®-THERM can be used both under tile and metal roofing. Due to its high strength, the membrane remains functional for a long time and is very durable – even under extreme conditions.

Thanks to its high resistance to UV radiation for up to four months, DELTA®-THERM offers the greatest possible safety even in the event of unplanned construction delays.  

Durable reliability – with a guarantee We confirm the outstanding quality of Dorken and its long-term functionality in writing: our 20-year functional guarantee.


Technical data: DELTA®- THERM

MaterialWhite film made of non-woven polyester and water-repellent and diffusion-open coating made of acrylic dispersion with a special light gray acrylic coating with high resistance to UV radiation. DELTA®-THERM PLUS with integrated self-adhesive edge for quick, windproof installation.
ApplicationVapor-permeable roof membrane for ventilated metal roofing (metal tiles, flat sheets, “click”, trapezoidal sheets). Also for solar and photovoltaic panels.
ZVDHClass UDB-A / USB-A   (highest class)
Fire resistanceEuro class B-s1, d0, EN 13501-1 (non flammable the highest class for polymeric materials)
Tear strengthapprox. 285/230 N / 5 cm, EN 12311-1 + 2
Water tightnessClass W 1, EN 13859-1 + 2
Sd valueapprox. 0,02 m, EN ISO 12572
Service Temperature range-40 °C to +100 °C
Short-term maximum temperature load of the material+150 °C
Resistance against driving rain
Pass in the driving-rain test for waterproofing and soft sheathing, TU Berlin
Increased requirement for agingPassed, ZVDH product data sheet table 1
Weightapprox. 220 g/m²
Roll weightapprox. 16,5 kg
Roll size50 m x 1,50 m

Accessories for DELTA®– THERM PLUS / DELTA®– THERM

DELTA Than ico
DELTA Nail Seal taoe ico
DELTA Multi Band ico
DELTA Flexx Band ico

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