Timber degradation and protection. Timber preservative treatment

9 dezembro 2020, 12:30 • Augusto Martins Gomes

Standards and Euro Norms for timber design and durability.  Wood: growth rings, summer and spring wood, heartwood and sapwood. Timber water content. Equilibrium water content.

Durability of the various wood species – EN 350. . Wood degradation causes and processes. Timber degradation by physical and chemical agents. Sunlight and exposure to dying/weting cycles with large amplitude. Wood decay by biological agents. Timber degradation by wood-destroying insects and fungi. Natural durability and treatability of wood species – EN 350. Classes of environmental exposure risk – EN 335.

Preservative treatment requirements and natural durability of solid wood - EN 460 - fungus, borers and termites. Conservation and protection of wood: wood specie selection and protection actions.

Timber preservation products; oily, aqueous (CCA, CCD and CCF) and organic solvent. Treatment processes: brush, sprinkling, dipping and pressure and vacuum impregnation.

Measures to prevent the progression of the wood degradation: environmental moisture control, protection against the water contact. Timber surface protections: paints, varnishes and coatings.