Metsä Wood Spruce WeatherGuard is an improved moisture resistant plywood, which means that it is a spruce plywood panel with a hydrophobic surface. The surface of the improved moisture resistant plywood rejects rainwater and therefore reduces the amount of water absorbed by the panel during construction work. At the same time the surface allows the improved moisture resistant plywood panel to breathe and water vapour to move freely.
During construction, it is common for building materials to get wet because of rain, and reasonable amounts of wetness can be expected during a typical construction. It is essential to allow wood-based components to dry before the components are fitted into the final structure. Otherwise moisture can lead to mould growth. Good construction site planning takes protection from the rain into account, and protects all moisture-sensitive building materials.
The colour of WeatherGuard treatment is transparent. The surface can be further treated with paints, lacquers, varnishes and protection treatments applicable on Wood products. The compatibility of the surface treatment is recommended to be confirmed from the supplier. Also carpets, linoleum, tiles etc. can be glued to the surface.
Tested performance of the improved moisture resistant plywood
During field tests in typical construction site settings, full size improved moisture resistant plywood panels of Spruce WeatherGuard were placed horizontally to simulate roof and/or floor structures. The 72-hour test demonstrated that Spruce WeatherGuard improved moisture resistant plywood panels absorbed only half of the amount of water compared to untreated spruce plywood. Due to the lower moisture content of Spruce WeatherGuard also the needed drying period is shorter. In the tests the difference of the drying period duration was 48 hours.