Mjøsa Tower (Mjøstårnet) by Trondheim-based Voll Arkitekter, the world's tallest wooden skyscraper, is over 4.5 meters higher than planned! Now structurally topped out, the 18-story structure stands 85.4 meters tall and is officially the world's tallest timber tower.
The construction, which started in early April this year and will be completed in March 2019, is an example of how wood can be substituted for concrete. The 18 story-building will housing offices, a hotel and apartments.
The construction, which started in early April this year and will be completed in March 2019, is an example of how wood can be substituted for concrete. The 18 story-building will housing offices, a hotel and apartments.
“The floor structures, which consist of massive beams with Kerto panels on top, are assembled in our factory, just 15 kilometers from the construction site. Obviously, that’s a huge advantage if you have something that needs to be adjusted at the factory. The work is progressing at the rate of one story a week, which has shortened our construction time by approximately 35 to 40 per cent compared to using cast-in-site concrete. And since the wooden components are so lightweight, we don’t need the machinery to be as heavy,” says Rune Abrahamsen, Managing Director of Moelven Limtre AS, a general subcontractor in the Mjøsa Tower project.
Fire safety is not a weak point in the wooden Mjøsa Tower. Untreated solid wood creates its own fire-resistant surface because the outermost layer chars when exposed to fire, protecting against further fire damage.
In fact, wood is a fireproof material despite the commonly held belief that it isn’t. “Fire safety rules state that buildings must be able to withstand a full fire for at least two hours without collapsing. When you have a building made of steel and concrete, the steel melts and the building collapses,” says Erik Tveit, Project Manager at HENT AS, the general contractor for the site.
Nevertheless, concrete will be used between the floors of the Tower’s top seven storeys. Using concrete has nothing to do with the load-bearing capacity. There’s a simpler explanation: the swaying that increases the higher you get in a building built of wood or concrete. The weight of the concrete in the upper storeys makes the swaying slower and not as readily perceivable.