The Natural Durability of Danish Forest Trees Grown Externally With No Soil Contact
Project start 1999. Expected completion date not determined.
The timber panels were postponed at the beginning of 2000. The project is complete when the timber has degraded.
Twenty variants of European trees are being tested for their natural durability; Danish Common Spruce (Whitewood), Norway Spruce (wihitewood), Silver Fir, Grand Fir, Sitka spruce, Douglas fir, Douglas splint fir, Western red cedar, Skotch Pine Danish (redwood), Scotch Pine Northern Sweden, European Larch, Siberian Larch, Western Red Cedar North American, Lawsons Cypress, Ash, Oak, Red Oak, Robinie, Asp, Scotch Pine waterproof, Class AB (reference Product).
After almost 9 years of exposure, it has been established that all trees succumb to mould fungus, though in some cases this can happen faster and to a larger extent.
All trees spruce when they are exposed directly to the weather. This will happen within the first year. All timber panels made of Danish-grown Scottish Pine and exposed without cover have degraded.
- Establish tests to build knowledge over an extended period on the natural durability of Danish trees with no soil contact.
- Impart knowledge about Danish-grown trees’ absorption and emission of moisture when exposed to the weather, and subsequent risk of degradation.
- Create a demonstration area to exhibit the usefulness of Danish forest trees’ as external covering for the benefit of the construction industry and other potential customers.
- Compare certain foreign trees as potential competitors to Danish ones.
- The Danish Technological Institute in collaboration with The Danish Forest and Nature Agency.
- During the first 3 years the wood moisture was measured each second month. After this time, the degradation of the wood was evaluated once a year. Likewise, an annual photograph of each tree is taken.