Roofing membrane, underlay and self-adhesive roofing membrane
The ideal roofing membrane for maximum protection and quick installation
For insulation to work perfectly, it requires a reliable protective barrier against wind, driving rain and extreme weather conditions. Whether it’s a roof underlay or a roofing membrane – ensuring reliable protection for the roof structure is the top priority. ISOCELL’s OMEGA roofing membranes provide precisely this outer protective layer for your timber structure and ensure that the entire building retains its value in the long term.
Thanks to sophisticated, integrated self-adhesive strips (SK DUO), installation on site is particularly quick, secure and permanently windproof.
Roofing membrane, underlay and self-adhesive roofing membrane: definition and distinction
Roofing membrane / underlay:
In everyday construction, various terms are often used to refer to the outer protective layer. Traditional roofing membranes protect the structure from direct exposure to the elements during the construction phase and, once the building is complete, serve to prevent water ingress into the building, e.g. due to ice dams or any damage to the roof covering.
Self-adhesive roofing membrane (i.e. with integrated acrylic adhesive strips on both sides):
These modern systems feature integrated adhesive strips. They save your team valuable working time, as they enable a quick, wind- and rain-proof bond between the membrane overlaps without the need for additional adhesive.
Why the roofing membrane is crucial for the building envelope
The outer roofing membrane acts as a windproof layer and protects the insulation from external influences.
- Windproof sub-roof construction: A sub-roof design that prevents harmful airflow through the thermal insulation, thereby ensuring it achieves its full thermal insulation performance.
- Energy efficiency through windproofing: The insulation can only perform to its full potential if the windproof layer is completely sealed. Cold outside air must not be allowed to flow through the insulation layer.
- Quality assurance during construction: High-quality membranes offer a long weathering life. This gives your team maximum flexibility should the final roof covering be delayed.
Construction of the sub-roof that prevents harmful airflow through the thermal insulation material (which would reduce its thermal insulation value).
Expert tip: Save time and money with pre-fabrication
Maximise efficiency on site: with pre-cut roofing membranes (in 2D or 3D), you can significantly reduce installation time and minimise waste. The membranes are cut to exact dimensions at the factory and heat-sealed – ideal for complex geometries and perfectly compatible with our high-performance roofing membranes.
Instructions: Guidelines for the correct installation of the roofing membrane
New Build vs. Refurbishment
- In new builds: The installer lays the roofing membrane parallel to the eaves, directly onto the rafter structure or the formwork. Ensure that all joints are fully bonded to achieve windproofing immediately.
- In renovation: When renovating a roof from the outside, the roofing membrane immediately protects the exposed structure from sudden rain showers. Here, a roofing membrane with integrated alternating acrylate adhesive strips (self-adhesive roofing membrane) demonstrates its strengths by providing rapid protection against driving rain immediately after installation.
You can find detailed installation guidelines on our product pages, for example here: OMEGA MONO 200 SK DUO roofing membrane.
Professional ISOCELL solutions for maximum watertightness
To ensure a permanently secure roofing system, ISOCELL offers perfectly matched membranes and adhesive components:
Roofing membranes & windproofing membranes
Our highly tear-resistant roofing membranes offer your team maximum exposure times and the highest level of safety.
- OMEGA UDOs 330 roofing membrane: A vapour-permeable and weldable membrane for underlays with enhanced rain protection in accordance with ÖNORM B 4119. Meets the ‘Gebäudehülle Schweiz’ quality seal for underlay membranes. 5 months of open-weather exposure, for roof pitches from 1.5° (seam welding), for roof pitches from 5° (SK DUO).
- OMEGA MONOTOP 330 roofing membrane: Vapour-permeable membrane for sub-roofs with enhanced rain protection in accordance with ÖNORM B 4119. Suitable for bonded underlay / under-layering Class 3 in accordance with ZVDH. For use on roof pitches of 5° or more. Weather-resistant after 6 months, non-slip and stable with two integrated adhesive strips, easier to install, no buckling.
- OMEGA MONO 230 roofing membrane: Vapour-permeable roofing membrane for direct installation on thermal insulation or timber formwork; monolithic membrane. Suitable for bonded underlay / Class 3 underlay in accordance with ZVDH. Enhanced UV resistance and resistance to driving rain.
- OMEGA 180 roofing membrane: Vapour-permeable roofing membrane for direct installation on thermal insulation or timber formwork. 3-layer non-woven fabric combination. Suitable for Class 3 bonded underlay/under-sheathing in accordance with ZVDH. Non-slip and tear-resistant surface.
- You can find further roofing membranes here.
System accessories for permanent bonding
With ISOCELL’s tested adhesive tapes and sealants, you can seal overlaps, connections and component penetrations to make them completely wind- and rain-tight.
- OMEGA QUILLI adhesive sealant: For rain- and wind-tight bonding of roofing membranes in overlap areas and at connections. Adhesive sealant for sealing nail and staple heads in the counter-battens area. For bonding the edges of softwood fibreboard, OSB and MDF boards.
- PE NDB DSK nail sealing tape: Double-sided adhesive PE foam tape for sealing screw and nail holes beneath counter-battens. ≥ 5°DN. Thickness: 3 mm. Suitable for use with the nail sealing tape dispenser.
- You can find further accessories here.
Recommended products
Do you have any questions about your project? Our structural engineering team is here to help!
Every construction project and every refurbishment presents its own challenges. Our experienced ISOCELL Bautechnik team will be happy to assist you with planning the correct waterproofing layer, calculating U-values or answering any questions you may have regarding detailed design.
FAQ – Frequently Asked Questions
Our professional roofing membranes, such as the OMEGA UDOs 330 roofing membrane, are characterised by a very long weathering life. Depending on the system components selected, the membranes provide you with reliable protection against UV radiation and driving rain for several weeks or months. This offers your team maximum flexibility during the planning phase and on site, should the final roof covering be delayed.
A roofing membrane with integrated, interlocking acrylate adhesive strips significantly streamlines your team’s workflows. Thanks to the double-sided adhesive strips, there is no need to apply additional adhesive to the overlap area. This saves valuable time on site and ensures an immediate, wind- and driving-rain-resistant bond at the membrane joints – even in windy conditions.
