The new patented hybrid Sarnafil® AT technology refers to a versatile membrane that is easy-to-apply and long-lasting for sustainably designed roofs. Sika has combined all the best attributes of single-ply roof membranes into one new ‘Advanced Technology’ Sarnafil® AT.

A New Generation of Roofing Membranes

Unique Hybrid Technology for a Smarter Roofing Experience

As the global leader in single-ply roofing, Sika has created a highly flexible membrane with the ultimate combination of durability, sustainability and ease of installation. The new technology combines advantages from all existing membrane technologies, with good durability and the freedom of design, to flexibly adapt to different project demands.

Sarnafil AT
Sarnafil AT

Hot Air Weldable Roof Membrane Formulated for Direct Exposure 

Sarnafil® AT is a membrane based on flexible polyolefins (FPO), with internal fabric reinforcement and backing in accordance with EN 13956. The membrane is fully compatible with all existing Sarnafil® T accessories and ancillary components.

Sarnafil® AT is a hot air weldable roof membrane formulated for direct exposure and designed for use in all global climatic conditions.


Roof waterproofing membrane for:

  • Mechanically fastened systems
  • Ballasted systems e.g with gravel, concrete slabs and for green roofs (intensive & extensive), inverted roofs, plus on terraces with pedestrian traffic

Characteristics and Advantages

  • Resistant to UV exposure
  • Resistant to wind uplift
  • Resistant to all other common environmental influences
  • Hot air weldable¨
  • No open flames required
  • High dimensional stability with glassfleece inlay
  • Resistant against impact loading and hailstones
  • Resistant to mechanical influences
  • Resistant to root penetration
  • Compatible with existing bitumen

Sarnafil® AT: Cradle to Cradle Certified™

Sika embarked on its first Cradle to Cradle Certified® project for Sarnafil® AT in 2020. Sika was successful in achieving an overall certification level of Silver for the product in in accordance with version 3.1 of the Cradle to Cradle Products Standard. Sarnafil AT® also received scores of Gold for the Material Reutilization and Social Fairness categories.  

As part of the Cradle to Cradle Certified™ process, Sika has also published a Material Health Certificate for Sarnafil® AT. The Material Health Certificate offers a solution to growing industry and consumer interest in knowing more about the chemicals used in products across their supply chains and avoiding chemicals of concern.  

A white paper explaining Sarnafil® AT and the Cradle to Cradle Certified® program was published by Sika Germany and is available for download. 

Cradle-to-cragle Silver distinction for Sarnafil AT

Continuous Improvement Journey

Sika is working to continuously improve the sustainability performance of Sarnafil® AT as part of its commitment through the Cradle to Cradle Certified® program. In 2022, Sika initiated a feasibility study to assess its strengths and weaknesses to meet the new and more robust requirements of v4 of the Cradle to Cradle Products Standard. Each quality category was assessed in detail, determining which to transition to v4 in its recertification which will be completed in early 2023.  

The Clean Air and Climate Protection and Product Circularity categories will be recertified in v4, while the Material Health, Water Stewardship and Social Fairness categories will be kept in v3.1 and will be further assessed as part of the next certification cycle. 

One key area for further study for the Sika team behind Sarnafil® AT is testing around the increase of inclusion of recycled material within the roofing membrane. Currently, the membranes include a small percentage of pre consumer recycled content from scrap material during the manufacturing process. Because the recycled content originates from Sarnafil® AT’s own manufacturing process, it is not possible to increase the amount of recycled content from this source. Trials and tests are underway to determine the feasibility. However, because Sarnafil® AT membranes are new products with a service life of >30 years, there is very limited availability of recycled content for further cycling.of including post-consumer compatible recycled content from old roofing systems, from sources where chemical traceability is available and chemicals of concerns are avoided. Due to the high technical requirements of Sarnafil® AT, only end of life Sarnafil® AT membranes are currently considered as suitable post-consumer input material for the production of new membranes. The current trials focus on older generations of Sarnafil® membranes that are coming back from the market to inform the future cycling strategy for Sarnafil® AT.

As part of Sika’s net zero commitment, keeping materials in constant cycle has been identified as a key lever and will be one of the key focus areas for R&D in the coming years.  

For further information, please visit the Sarnafil® AT page on the Cradle to Cradle Products Innovation Institute’s website.

The Sarnafil® AT FSH Self-healing Technology

Roofing technology has seen a remarkable advancement with the emergence of self-healing solutions, thanks to the power of water-reactive polymers. With the advent of this innovative technology, roofs now possess the remarkable ability to heal themselves, offering a reliable way to protect critical building assets.

Explore the fascinating science behind water-reactive polymer technology and what factors to consider when deciding whether to use them on your projects.

Water-reactive polymer technology represents a remarkable innovation in the roofing industry. With its remarkable ability to autonomously heal minor cracks and punctures, the innovative Sarnafil® AT FSH Self-healing Technology provides an innovative yet reliable solution for building owners and contractors seeking to protect high-value or critical assets.

Advantages for Owners and Designers

Sarnafil AT


Sarnafil AT® is the first and only thermoplastic roofing membrane in the market to be Cradle to Cradle Certified™.

Sarnafil AT

Hail Resistance

High resistance to impact and damage e.g. hail, to ensure a longer service life.

Sarnafil AT

Long Term Performance

QUV tested for long-term service and durability for decades.

Sarnafil AT

Interview with a Project Owner

What does the owner of the roof refurbishment project at Leister Building think about Saranfil® AT after it has been applied on Leister’s roof?

Advantages for Contractors

Sarnafil AT

Highly Flexible

Highly flexible like EPDM, even at low temperatures, which allows faster rollout of the membranes on site.

Sarnafil AT

Easy to Apply, Faster Installation

Easy, faster application and detailing work. Self adhesive tapes and membranes for detailing and upstands.

Sarnafil AT

Hot Air Weldable

Easy to weld and produce reliable welds like PVC, but also with an even wider welding temperatures window.

Sarnafil AT

Interview with a Roofing Contractor

What does the contractor of the roof refurbishment project at Leister Building think about Sarnafil® AT after it has been applied on Leister’s roof?

Sarnafil AT


A wide variety of accessories are available, as it is compatible with all existing Sarnafil® FPO-Systems. 

Sarnafil AT

Impact/Puncture Resistance

High resistance to impact damage, which helps to avoid punctures during installation and service.

Sarnafil AT

Welded Seam Performance

Seam collapse test value of more than 3 x that of EPDM, for long-lasting waterproof seams.

Sarnafil® AT-Technology: Thermoplastic + Elastomer

Sarnafil® AT-Technology

Sarnafil® AT is an elastomer modified FPO Membrane for roofing applications. The technology combines the advantages of FPO and elastomer membranes (as a hybrid). That means the Sarnafil® AT has excellent and easy weldability, safe and easy application (no solvents), high hail resistance and good application behaviour at low temperatures. Sarnafil® AT contains FPO thermoplastic and elastomer.


Thermoplastics consist of long, threadlike, unlinked molecular chains. Thermoplastics can easily be deformed in a certain temperature range. This process is reversible, i.e. it can be repeated as often as desired by cooling and reheating to the molten state. With rising temperature, the molecular chains become increasingly mobile during the melting process. They may also disentangle themselves and slip apart. This molecular mobility makes it possible to weld the membrane.


Elastomers are plastics whose special property is their high rubber-like elasticity, even at low temperatures. Elastomers are therefore dimensionally stable, but as they are elastic will return to their original shape after deformation. The molecular chains of elastomers are described as being wide meshed.