24-meter roof elements enable fast installation

LapWall, Finland's largest wooden element manufacturer, has been involved in numerous demanding construction projects. One prime example is Metsä Wood's new Kerto LVL mill under construction in Äänekoski. In this project, LapWall was responsible for delivering the roof, including the design, manufacturing, and installation of roof elements. The roof spans approximately 47,700 square meters, equivalent to six full-sized football fields. 

Roof elements measure up to 2.5 meters x 24 meters, enabling the fast and safe coverage of large areas with minimal lifts. Up to 1,500 square meters of finished roof can be installed in a single day. “This is the largest individual project delivery in our company’s history,” says Marko Kellberg, LapWall's Business Director. 

Wooden elements accelerate construction projects 

LapWall specialises in wooden wall and roof elements, which are increasingly in demand due to the rise of industrial construction methods. This approach focuses on pre-manufacturing structural components in factories before transporting them to construction sites. Compared to on-site construction, pre-fabricated products shorten project timelines, improve quality, and reduce moisture-related risks by shifting more work into controlled factory environments.

"The key advantage of element construction is that most challenges can be resolved during the planning phase. On-site construction, on the other hand, often requires last-minute adjustments, which may remain undocumented and complicate future maintenance," explains Kellberg. 

Precise carbon footprint data available 

The roof elements for the Äänekoski mill were produced at LapWall’s factory in Pälkäne within 5.5 months. The elements were transported wrapped in protective plastic, which was removed only upon installation, eliminating the need for additional weather protection and saving time. Lightweight wooden elements also provide logistics advantages. For example, LapWall's delivery to Äänekoski included 696 roof elements, requiring 196 truckloads, far fewer than for concrete elements. Additionally, waste is minimized as the plastic wrapping and any leftover wood can be 100% recycled.

“LapWall is the first wooden element manufacturer globally to create independently verified carbon footprint calculations for its products,” says Kellberg. Environmental Product Declarations (EPDs) provide detailed information on the carbon footprint across the supply chain, allowing builders and designers to assess the environmental benefits of using wood as a construction material. 

Kerto LVL: a material-efficient choice for element manufacturing 

LapWall uses Kerto LVL in its products, particularly as the primary beam in roof structures. Kerto LVL enables the creation of lightweight, hollow wooden elements that are exceptionally strong and material-efficient. Its hollow structure allows for integrating insulation and ventilation systems directly into the elements. 
In the Äänekoski project, the roof structure required approximately 800 cubic meters of Kerto LVL. "Our long-standing collaboration with Metsä Wood works exceptionally well. They deliver Kerto LVL cut to precise lengths, ensuring we can keep our inventory small," says Kellberg. The technical properties of Kerto LVL, including its strength, rigidity, and dimensional stability, make it ideal for element production, even under varying temperature and humidity conditions. 

LapWall has also supplied wooden elements for previous Metsä Group mill investments. According to Kellberg and Metsä Wood's Sales Development Director Jyrki Uimonen, successful projects rely on excellent collaboration. In Äänekoski, this cooperation between Metsä Wood, the main contractor SRV Construction, and LapWall has been exemplary. Roof installation began in November 2023 and was completed by June 2024, divided into 13 installation phases to ensure rapid progress. “With thorough pre-planning and project management, the project advanced smoothly. The best construction projects are seamless teamwork initiated as early as possible,” Kellberg notes. 

"The success of excellent collaboration is also reflected in the timely production planning, manufacturing, and supply chain deliveries of Kerto LVL products to LapWall," adds Jyrki Uimonen.

Metsä Wood's Executive Vice President Jaakko Anttila emphasizes the project's safety and quality: “A construction project of this magnitude demands top-level expertise and seamless collaboration between all parties.” 

The Metsä Wood Kerto LVL mill in Äänekoski is set to be completed by the end of 2026, with an annual production capacity of 160,000 cubic meters of laminated veneer lumber, increasing Metsä Wood's Kerto LVL production capacity by approximately 50%.