Water vapour transmission properties of uncoated and coated wood-based panels

Knowing the properties of wood-based building materials is essential for their proper use. Moisture transfer properties of building materials are crucial to proper building design and the prevention of moisture-related problems. In selecting materials for the building, it is important to know their water vapour transmission properties. In this research the water vapour transmission properties of uncoated and coated particleboard, oriented strand board (OSB) and birch plywood were studied using wet cup method and a moisture gradient in the samples was additionally measured. The water vapour transmission rate of free films of three commercial transparent coatings was also studied. Results showed that particleboard had the highest water vapour permeability and that the coatings reduced the water vapour permeability of all tested wood-based panels. Moreover, sanding increased the water vapour permeability of uncoated particleboard and OSB. The moisture gradient in all tested wood-based panels was linear. The highest water vapour transmission rate was recorded for acrylic water-borne coating, followed by polyurethane waterborne coating and the lowest for polyurethane solvent-based coating.

Automated summary

Understanding the moisture transfer properties of wood-based building materials is crucial for proper building design and prevention of moisture-related problems. This study investigated the water vapor transmission properties of particleboard, oriented strand board (OSB), and birch plywood, revealing that particleboard had the highest water vapor permeability and coatings can reduce the water vapor permeability of wood-based panels.