Wooden floor underground
The structure is an external wall with a wooden frame that goes down below ground level and down to the foundation. The underground installation means that the wall is occasionally exposed to significantly higher moisture loads (in the vapor phase) than a normal exterior wall is exposed to. The temperatures also deviate from what is normal for an external wall.
Measurements, simulations and analysis are focused on the wood material towards the outside of the structure. The results show that the current solution Wooden floor underground is possible and satisfactory under certain conditions where wood material with initially low moisture content (12-13% or lower) is recommended as the possibility to dry out in the enclosed space is limited. It is crucial that the structure is designed and produced in such a way that water cannot leak in (sealing of existing joints, tight vapor barrier, etc.). This must be ensured by selecting materials and products that retain their function over a long period of time and by careful quality control work.
Two unplanned incidents with water in the structure during the construction phase and later during the operational phase in the form of a heavy downpour and a leak from a water tap entering the structure via a threshold also provide an indication of the robustness of the structure. Despite these incidents, measurements show that the climate and moisture content around and in the column closest to the outside is relatively constant. Measurement results after incidents have shown elevated values of relative humidity and moisture content inside the floor slab itself. An action plan was developed and a forced dehydration was carried out. After dehydration, the measurements now show a normal climate.
Area: Industrial wood construction
Budget: SEK 270,000
September 2019 - December 2021
Project leader: Göran Berggren, RISE
Funding: This project is funded by TCN.
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