(a) Durability Natural Wood
Durability is defined as the durability of wood against wood destroying factors of biological groups. Natural durability is determined by extractive substances that are toxic to destructive factors before, so that by itself this natural durability will vary in accordance with variations in the number and type of extractive substances. This causes the natural durability varies according to the type of wood the same and in the same tree.
Variations durability in the same tree occurred between sapwood with kayuteras. Sapwood has a durability that is low because it does not contain sapwood extractive substances. This is why the durability of wood based classification is based on the durability of the wooden porch. Variations durability is also present in wood patio, where the wooden porch is more durable than outer timber interior patio. It is linked to the age of trees when the timber is shaped terrace.
Seeing things above, then for testing the durability of something kind of wood, sampling should be done with caution. In Indonesia, natural durability of wood is divided into five classes based on age / age and condition where the use of wood as shown in the table was made by Pfeiffer and has been corrected by the LPH. Age / lifetime (in) the year according to the categorization of durable:
This division applies only to the lowland tropics and do not include resistance to marine worms.
(b) Permeability Wood
Permeability is defined as the ease of wood redeemed by the liquid. Just like on the durability of the wood permeability varies greatly. Sapwood has good permeability properties as part of this was to function as a water delivery from the root to the leaves. Wood patio mempunyia poor permeability properties, due to the formation filosis and other deposits that cover the cells of the wood.
Permeability wood serine also called treatabilitas namely ease of wood treated / preserved.
Wood Treatabilitas divided into three groups, namely:
a. Sarang (Permeable): Wood can be penetrated entirely within the cylinder press or easy diimpreginasi on randaman process.
b. Medium (Moderate): Internal Penetration of ¼ – ½ inch (o, 6 to 1.2 cm) can be achieved within 2-3 hours under pressure
c. It is difficult (Difficulf): Wood requires a very long time to achieve a penetration depth of 1/8 – ¼ inches (0.3 – 0.6 cm) under pressure.
(c) Natural Durability Testing
Natural durability against wood destroying class of biological factors can be determined in 2 ways ie:
a. How to Grave
In this way, the wood in a certain size are planted in the field and examined in a certain period of time to determine lifetime / her age. This method has disadvantages, among others:
– When testing is very penjang so difficult in the observations.
– Field testing should always be treated so as not to turn into bushes.
– It is difficult to establish whether the destruction of the wood caused by fungi or termites, when both factors are found together in the field of testing.
b. Method Laboratory
In this way time is shorter and the age / lifetime of the wood is determined from the magnitude of the weight loss test sample. This method overcomes the disadvantages of grave manner, but also still has a weakness among others are the only kinds of wood destroying certain that can be cultured in the laboratory and difficult set of conditions in accordance with the normal environmental conditions.