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Lett-Tak develops wood-based roof element - Increased focus on sustainability

With over 40 years of experience in tailoring roof solutions for a wide range of buildings in the Nordics, Norwegian Lett-Tak has now expanded its range by developing a new environmentally friendly roof element. This is achieved through the development of Lett-Tak Wood, a wood-based roof element. The development aligns with Lett-Tak's focus on sustainability. The new roofing element uses Kerto® LVL, and the first project - Os Hälsohus - has now been completed. The project has received positive feedback and the outlook for the future looks good in Scandinavia.
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  • Kerto LVL, Offsite construction

A successful project for a new roof element  

When Os municipality in Norway decided to build a new health center, they had a vision of a future-proof building. With a newly adopted climate and energy plan, the requirements for the building were high, and the tender documents included a 20 percent weighting of wood in structures and insulation.  

“Os municipality's focus on the environment and climate for this project was impressive. With our new roof element made of 100 percent wood, we were able to meet the climate footprint requirements for the project as requested by Os Municipality,’ says Johan Aas, CEO at Lett-Tak. 

 

Freedom of choice for the customer 

Lett-Tak has four decades of experience in roof structures. Over the years, it has developed many customised solutions to meet the requirements of various projects. Lett-Tak Wood will be their first roof element that is entirely wood-based.  

”The right material should be used in the right place, and Kerto LVL is material-efficient when it comes to roof structures. Lett-tak Wood element is also demountable, reusable, and almost 100 percent recyclable," says Tommy Nilsen, Sales and Marketing Director at Lett-Tak. 

From idea to product in two years

Lett-Tak and Metsä Wood have a long history of cooperation, and when the new wooden and compact roof element was to be developed in 2020, Metsä Wood's Kerto LVL was considered to have the required properties.  

"Kerto LVL is a resource-efficient and stable material with long spans, high strength, less deflection, and low weight," says Tommy Nilsen.

At the end of 2023, the first Lett-Tak Wood element were used at Os Hälsohus. The prefabricated roof elements were quick to install, helping to create a watertight building faster than if the roofs had been built on-site. This shortened the construction time as the contractor could start building inside the house more quickly. This roof has a U-value of 0.09 W/m2K and the surface is solid, making it optimal for attaching solar panels.  

Creating a unique production line for Lett-Tak Wood 

Lett-Tak views the collaboration with Metsä Wood positively, and the new roof element has become a success, creating a ripple effect, as they have received several inquiries about Lett-Tak Wood for new projects. This has contributed to the construction of a new automatic production line for Lett-Tak Wood, which was completed in April 2024. Lett-Tak Wood tailors the roof elements to the customer's wishes and can be adapted up to spans of 16 meters with U-values down to 0.07 W/m2K. 

"We have several projects underway where Lett-Tak Wood will be used, including in Sweden. If we are to build more sustainably, wood will be an extremely important material in the future," says Tommy Nilsen. 

Summary
Products used Kerto LVL
Applications Offsite construction
Country Norway
Type Public buildings
Client Os municipality
Wood component supplier Lett-Tak