Today, a race is ongoing around the world to build the tallest building with a load-bearing wooden structure. In Sweden and the other Nordic countries, there are examples of buildings that can take part in the competition, but most agree that the large volume of buildings is in residential buildings up to a maximum of 10 floors.
In the last decade, this market segment has been of great interest to the wooden house companies, which have a material-efficient construction method and high competence in prefabricated construction. When these wooden house builders want to build up to ten storeys tall residential buildings, a number of challenges arise.
One of these is that the house deforms vertically over time due to its own weight and imposed load. The greatest deformation occurs in the places where the wood material is loaded perpendicular to the fiber direction.
The current project aims to investigate the possibilities of using an alternative product at the places in the building where loading takes place perpendicular to the fiber direction. The alternative product consists of boards sawn from residual material from production of CLT panels.
This residual material arises when customers who buy CLT-panels want the manufacturer of these to also saw openings for, doors and windows. The idea to be investigated is whether these “cut-offs” can be sawn into boards and used as top and bottom rails in modern prefabricated wooden houses.
As the load takes place in parallel with the fiber direction in every other layer in such boards, it is likely that this board will decrease the amount of vertical deformation and thus solve one of the obstacles that has hindered the development of taller residential buildings with timber frame.
Participants
AB Hilmer Andersson, Dynalyse AB, Karlstad University, Linnaeus University, Moelven Byggmodul AB, Obos Bostadsutveckling AB and Villa Vida AB.
Budget & time plan
The project’s total budget is 1 090 000 SEK and the project runs duriing six months – between November 2020 and May 2021.
