Biological factors attack the wood for two things, ie wood as a food or as a residence.
(1) Micro Organisms
Fungi and bacteria, both also called micro-organisms and classified into four sections based on the nature of development in the wood and the shape of the damage.
(2) Fungi Wood
This fungus is the most important class of micro-organisms, because this class of physical or chemical change timber.
(3) Fungus Shadow Wood
Fungi belonging to the wood dyes such famous names as membei blue-stain splotches of blue color on wood attacked. This fungus is composed of fungi-fungi Ascomycetes and Deteromycetes which among others are: ceratocyctis SPP, SPP Diplodia, and Graphium SPP. Boletus-mushroom is not menyerangdinding-wood cell walls, which are edible organic materials contained in the cell so lumens suspected that the physical strength of the wood is attacked unchanged.
(4) The fungus in the Surface
This fungus grows only on the surface of the wood, so the mycelium-miceliumnya not penetrate this part of the timber.
(5) Bacteria
These bacteria do not eat wood, but wood use as a residence, the color of the wood that was attacked has not changed but the permeability of the wood the better.
(6) seranga
Especially wood destroying insects is rayp.Rayap wood attacker because the main food ingredient is wood cellulose. Shape of the damage they cause damage called spider attack, because the attack was the cell walls of the wood strength will sangatmenurut. Generally, termites attack wood first has diserangcendawan-wood destroying fungi.
Besides termites, there are other peusak insects such as wood powder dry and wet powder.
(7) sea worms (Marine borer)
Wood destroying sea worm is attacking the wood used in salted water (sea).
Non Biological Factors
Vandal non biological factors are all factors beyond the biological group that can cause damage to the wood. The damage is partly due to the effects of:
(1) Mechanical damage caused by the operation of the force (load) from the outside of the timber. Among others abrais mechanical damage wood, for example in railway sleepers.
(2) The chemicals consisting of bases, acids or salts, but compared to iron, wood secra generally much more resistant to chemicals
(3) The physical factor is the air, light, water and fire, wood disclosure would constitute a malfunction of the air, because the wood has hygrostropis properties and development properties shrinkage.