Plywood Has Good Biological Durability

The biological durability of plywood refers to its ability to resist decay and damage caused by biological stresses such as fungi, insects, and bacteria. The biodurability of plywood can be most effectively improved by ensuring proper storage and conditions of use, while coatings and protectants provide additional protection.

Due to its positive impact on the climate and its wide range of uses, plywood is becoming increasingly popular as a building material. When using plywood, it is important to consider its specific characteristics, such as its biological durability. This paper discusses the effects of wood raw materials, gluing, coating and treatment as well as use conditions on the biological resistance of plywood.

In general, the biological tolerance of plywood is similar to that of the wood used in its manufacture.The biological durability of spruce plywood is naturally slightly better than birch plywood. Because spruce is less hygroscopic and therefore absorbs water more slowly, the natural durability of spruce can be considered better than standard classification, especially on the ground. As a result, spruce can withstand various conditions in construction applications.

Select the right plywood according to its type of use

Use Category 1: Used inside buildings, not exposed to weather and humidity.

Use Category 2: Suitable for plywood that is covered and not exposed to the weather, but occasionally wet.

Use Category 3: Suitable for outdoor use where plywood is located above the ground and exposed to the weather.

Subclass 3.1: For cases where plywood does not remain wet for a long time.

Subclass 3.2: Suitable for use where plywood is kept wet for a long time.

Use Category 4: Suitable for use where plywood is in direct contact with groundwater and/or fresh water.

Use Category 5: Suitable for use where plywood is in direct contact with salt water.

Proper conditions can prevent decay

Despite the use of weather-resistant gluing, the moisture resistance of uncoated plywood with unsealed edges remains limited under outdoor conditions. Wood rot is caused by fungal attack. If the relative humidity of the air exceeds 85%, the moisture content of the plywood will rise to more than 20%. Under these conditions, if the temperature is +3... At +40°C and with oxygen, plywood may rot.

The risk of fungal infestation can be avoided by using the right conditions of storage and use and correct construction methods that eliminate some of the above factors.

Wood protectants prevent discoloration and rot

Mold or blue spot fungus may also appear on the plywood. These mainly cause discoloration of plywood. Mold only grows on the surface of wood. Cyanine acts on soluble substances in the wood cells and therefore does not significantly weaken the strength of the plywood.