Stork: a natural stone and cork sandwich for flooring and walls

Sandwich made of natural stone and cork

A new Portuguese product combines two of the countries natural resources

„Stork“, not to be confused with the bird of the same name, is the name of an innovative fused product made of cork and thin layers of natural stone. Not surprising that the idea originated in Portugal: the country plays a significant role as a supplier of stone on the world markets and calls vast cork oak expanses its own.

Stork is a sandwich made up of 3 or more layers: in case of flooring, the first layer is cork 15-30 mm thick and made of cork granules as a waste product of cork production. The material is similar to cork pin-boards or tiles.

Fiberglass backing bonds the natural stone and cork layers.

The cork particle-layer is covered by a special fiberglass resin layer for increased cohesion. Frontwave, the company responsible for the innovative technology, is currently working on a version using „natural fibers like sisal or jute“, according to Vera Pires of the Borba and Sintra-based science and consulting company.

The top layer is made of 8-10 mm-thick natural stone. Perfect adhesion is the secret to ensuring that the thin stone layers do not crack, as Vera Pires explains.

In principle, any type of stone is suitable. Depending on the needs of the venue at hand, other special layers can be applied under the sandwich, e.g. to repel upwelling water.

Stork has other advantages too: its mass is considerably less than that of stone alone and the cork comes naturally equipped with soundproofing and insulating properties. As a bonus, Stork is said to be about one third cheaper than stone flooring according to Frontwave’s Website. The mass depending on thickness of the stone layer is 17-22 kg/m².

Stork’s technical data

Sheer endless trials were run, starting with a variety of mechanical stress tests to fire resistance (Euroclass A1/A2) or longevity. Stork passed every one with flying colors. Other cork laminates are used today, e.g. in aviation.

Among others IteCons of Coimbra University, the Instituto Superior Téchnico of the University of Lisbon, as well as the Agency were involved in testing.
Stork tiles for flooring come in a maximum size of 1×0.8 m and can even be applied to elevated floors.

Frontwave has develop a bracket system to enable mounting Stork on interior or ventilated exterior walls. For these uses the maximum tile size available is 2×3 m.
Special anchoring is available.

For exterior walls stone of a mere 1 mm thickness can be used. Also, the application of bas-relief stone layers on cork is also possible.

Kitchen countertops can also be made of Stork.

Frontwave has been involved in research for 16 years active in development and consultancy in the stone branch from the quarry to the value-added product. The Company is a spin-off of the Instituto Superior Téchnico of the University of Lisbon.

Stork was developed as an answer to growing demand for ultra-thin stone products.

Frontwave entertains its own production next to the research and development divisions. The stone for Stork-production is acquired from certified members of the building branch and the cork is provided by Amorim ACC, a subsidiary of the world’s leading supplier.



Renderings: Frontwave

Stork’s technical data

(12.04.2017, USA: 04.12.2017)