On this site you will find many articles on how the construction industry embraces the concept of sustainable development and develop buildings, components and whole building systems with lower environmental impact. “We have worked with building materials for 30 years and for us, environmental issues have been with us the whole time,” says Daniel Radomski, CEO of the Buildsmart Group.

Cork is made from the bark of cork oak and is harvested manually.

“Almost all our products and solutions are associated with sustainable construction. For many years, we have collaborated with roof manufacturer Derbigum, which has many interesting materials and concepts. For example, they have a roof that traps atmospheric carbon dioxide, and a waterproofing method consisting of vegetable oils and resins,” says Radomski.

He continues: “When you build eco-friendly, the emphasis is often insulating as much as possible. Unfortunately, the focus is on finding out how much energy is required to produce the insulation material. To break down rock or mineral wool obviously takes great energy resources. Now we are launching in Sweden cork insulation for roofs and walls that we call Smart Insulation.”

Mostly air

Cork is an insulation material that has for many years been well established in many parts of Europe but has not yet found its way to Sweden to any great extent. In Sweden, mineral wool or foam is used. The eco-friendly alternatives have been available but had little impact.

“What finally convinced us to invest in cork was when we saw the example of the insulation in a house in Portugal installed in 1960 and still has the same properties and density as when it was installed. There are not many materials that have this durability,” says Radomski.

Smart Insulation consists of about 7 percent cork and the rest is air. Cork oak bark (read more about cork oaks in the article ”Thermoplastic elastomers – flexible and recyclable”) is harvested manually and allowed to dry outdoors for about six months. After the drying, the bark is boiled for 75 minutes and then the material is dried further for three months. The next step is to grind the cork granules where the combination of steam and heat make the granules bond together with their own resin.

Cork tiles can be formed to a desired size.

The result is slabs of expanded cork that can be cut in suitable sizes. The individual cork granules have small closed pores that do not take up water, but the spaces between them in the finished cork plate must be protected from water by a vapour layer.

“The cork that is used in the manufacturing of insulation is composed of waste from the production of wine corks and other cork products in Portugal. In addition, all the energy used when the cork tiles are produced from the combustion of cork makes all the parts environmentally friendly. If you start with the positive environmental impact of cork tree plantations and then look over the entire life cycle of the material, cork is unbeatable as an insulating material for green construction. We cooperate with the Portuguese company Amorin that produces insulation material for us, and who have a high level of ambition in terms of sustainable development,” concludes Radomski.

New roof on the pram factory

Insulation with cork keeps things dry and is noise dampening.

A few years ago, the roof of the Brio pram factory in Osby was poorly insulated and was in great need of repair. It used cork discs on an area of approximately 4,500 m2 and boards were fixed mechanically in the underlying flat roof. On top of the cork a waterproof layer of Derbigum (polymer modified bitumen carpet) was glued and the result was a tight, insulated and noise-reducing ceiling. Another advantage is that the cork contributes to good mechanical strength and the risk of treading through the ceiling or causing the failure is small.

The article was published in October 2013