New hybrid wall element combines concrete and wood

The manufacturing of concrete has a substantial impact on climate, and construction industry is looking for ways to replace concrete with climate-friendlier raw materials, such as wood.

Metsä Wood and its partners have designed a multi-layer sandwich wall element consisting of a Kerto LVL (laminated veneer lumber) panel, an insulation layer and a reinforced concrete layer that forms the facade. The load-bearing part of the element is the wood panel.

Compared to a concrete sandwich element, the hybrid element has many advantages. Not only is it more climate-friendly, but also light in weight and quick to install, since the joins between the elements require no further work. The casting and cleaning required for the vertical joins between concrete elements are not needed here.

The bottom edge of the hybrid wall element has attachments similar to those in concrete elements. The elements are simply screwed together.

The new wall elements were used in the log sorting building of the Rauma Sawmill, part of the same group of companies as Metsä Wood. The area of the building is 100 square metres. Installing the wall elements for the ground floor took five hours.

According to the construction company Skanska, using the new hybrid wall elements leads to a substantial reduction in the use of concrete. The elements are also lighter, bringing down the cost and environmental impact of transport and allowing the use of lighter equipment in installation.

’The lighter weight can bring considerable savings in a large construction project,’ says Petri Puputti, Construction Manager at Skanska.

’For a construction company, the new hybrid wall elements offer a more ecological alternative while requiring no changes in current construction practices,’ says Ilkka Romo, Director of the Productivity and Quality Unit at Skanska in Metsä Wood’s media release.

The wall elements used in Rauma were produced by Lipa-Betoni.

’After the initial challenges, manufacturing these elements was just as easy as making sandwich elements of concrete,’ says Satu Lipsanen, CEO of Lipa-Betoni.

The completion of the log sorting building was scheduled for the end of 2021, and the Rauma Sawmill will start operations in Q3 2022.