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The history of Dörken

Constantly setting new standards
with innovative developments

Company History Dörken As an autonomous subsidiary of Ewald Dörken AG (Germany) we at Cosella-Dörken are proud to continue in a leadership role as the manufacturer of premium quality products for the construction industry in North America. Here are a few of the milestones in more than a century of Dörken's history.


The parent company, Dörken GmbH & Co. KG, is founded.


Dörken produces roofing insulation membranes for railway carriages, becoming the basis for the company’s later involvement in composite construction sheets.


Dörken starts production of mesh-reinforced composite sheets. With DELTA®-FOL SPF the sharp development to European success in synthetic roof underlayments takes its course.


DELTA®-MS - an air-gap membrane for foundation protection - is launched. Within a few years, the chocolate-brown systems for foundation wall protection and drainage become a company trademark.


DELTA®-PURAFOL is launched as the first vapor permeable, reinforced roof underlayment on the market.


Dörken opens a production facility for foundation dampproofing, protection and drainage systems in Beamsville, Canada. The state-of-the-art production facility Cosella-Dörken supplies the North American construction market with premium quality products like DELTA®-MS, DELTA®-DRAIN and DELTA®-FL.

DELTA®-MAXX, a highly vapor permeable weather barrier membrane, is introduced into the European construction market.


DELTA®-FOXX, the highly durable synthetic roof underlayment and sheathing membrane, celebrates its premiere. A new high-tech production line is dedicated for manufacturing of this innovative material.


A new manufacturing plant in Hagen-Vorhalle (Germany) starts production. In this modern and highly efficient processing plant, many different types of DELTA® air-gap membranes and drainboards are manufactured in a variety of different sizes.

DELTA®-VENT, another innovative roofing and weather barrier sheet is launched.


The new energy-saving DELTA®-MAXX PLUS and DELTA®-TRELA, a vapor permeable sheathing membrane with attached drainage layer, are launched.

Furthermore a remarkable new high-tech fabric & geotextile manufacturing line goes online. With over $ 23 Million, this production line with its unique abilities is the company’s largest single investment to date.

Cosella-Dörken introduces DELTA®-MS CLEAR in North America, an innovative dampproofing membrane for insulated concrete form foundations (ICF).


Dörken GmbH & Co. KG introduces a combined system of quality, safety at work and environmental management to DIN EN ISO 9001:2000, DIN EN ISO 14001 and EMAS II (eco-audit).

DELTA®-COOL, a ground-breaking new method of passive indoor climate control based on PCMs (phase changing materials), is introduced into the European market.


Cosella-Dörken introduces DELTA®-DRY, a revolutionary ventilated rainscreen system to the North American market. The product has been specifically developed to solve moisture induced problems in the building enclosure behind absorptive claddings like 3-coat stucco, or manufactured adhered stone veneer.

The 'Thermomembrane' DELTA®-MAXX TITAN is launched. It reduces the heat flux into the roof by up to 9%, and reflects up to 50 % heat radiation.


Cosella-Dörken introduces a range of synthetic roof underlayments to the North American market. Amongst these products are DELTA®-ROOF for asphalt shingle roofs, DELTA®-VENT S and DELTA®-FOXX as highly vapor permeable underlayments for concrete or clay tile roofs, and DELTA®-TRELA for metal roofs. The product portfolio is rounded off by the energy saving roof underlayment DELTA®-MAXX TITAN with a highly reflective titanium coating.


Cosella-Dörken is being certified to DIN EN IS0 9001:2000.


DELTA®-FOOTING BARRIER is introduced to the North American market. This innovative barrier membrane provides a capillary break between footings and foundation walls, and helps to reduce the inward moisture migration into basements.

DELTA® is a registered trademark of Ewald Dörken AG, Herdecke, Germany.

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