What are the anti-insect methods for wooden houses? Wood decay is the result of being attacked by wood rot fungi. The hydrolysis of Hainan's antiseptic wood bacteria can decompose the cellulose, lignin and cell contents that make up the wood cell wall as nutrients, which gradually reduces the strength of the wood until it loses all its carrying capacity. The growth of wood rot fungi must meet the following three conditions: the wood moisture content is higher than 18%, the temperature is in the range of 2 ~ 35C; there is oxygen supply. If you can remove one of them, you can prevent decay. There is an old saying in China that "the millennium does not rot the bottom wood", which means that the wood lacks oxygen and does not rot in the water. The wooden structure is inseparable from human life, and temperature and oxygen cannot be excluded. The wood moisture content can only be controlled within 18%, even if it is in a dry state, to prevent the erosion of wood rot fungi. Therefore, it is required that all parts of the wooden structure, especially the key parts such as bearing nodes, should be in a well-ventilated condition, even if they are wet for a while, they can be dried in time. Preservatives are prepared from chemicals with certain toxicity, which are divided into water-soluble, oil-soluble, oil and paste. For wood components that are often exposed to moisture, it is advisable to use a mixed anti-corrosion oil, also known as shallot oil, which is an oil-based preservative. It is prepared from creosote (ie wood anti-corrosion oil) and coal tar. Asphalt is black and sticky in appearance, similar to scallion oil, and is often misused as a preservative. But bitumen can only be waterproof but not anti-corrosion. Using bitumen to coat undried wood is counterproductive and hinders the air-drying of wood. Insects that eat wood are mainly termites and beetles. Termites are more harmful than beetles. Common beetles that harm wood in China are House beetle, House beetle, Powder beetle, and long beetle. The beetle feeds on the fiber of the wood. The larvae worms into the tunnel. When they are mature, they pupate at the end of the tunnel. The adult worms emerge and bite out in an oval hole. It mainly harms broad-leaved trees such as Casuarina equisetifolia. The powder codling and codling feed on wood starch and sugar, so they mainly use sapwood that harms broad-leaved trees. Adults like to lay eggs in holes in the wood surface. Therefore, oak, hickory, locust and other tree species with larger tube holes suffer the most. The larvae worm the inside of the wood into a powder, leaving only a thin shell, and the surface of the worm is densely covered with powdery worms. Beetles mainly attack dry wood with lower moisture content, while termites are more harmful to damp wood. Therefore, taking structural moisture-proof measures to isolate the wooden components from the water source has a certain effect on reducing the damage of termites. However, the structural moisture resistance is only an auxiliary measure for insect control. In areas where there are termites or beetles, wooden structures and wooden products should be treated with insecticides. Phoebe, red sandalwood, teak and other tree species have strong termite resistance, and Chinese fir, cedar, camphor wood, etc. also have certain termite resistance, but most wood species are vulnerable to termite damage, such as masson pine is most susceptible to termite decay. Therefore, wood structures or wood products made of wood species that are susceptible to termite hazards must be treated with insecticides. In order to ensure the durability of the wooden structure, currently all countries in the world use anti-corrosion and anti-insect agents. For example, the boron phenol mixture prepared with boric acid, borax and sodium pentachlorophenol is a water-soluble agent. It can soak the wooden components in the aqueous solution of the agent. If the cubic meter of wood can absorb 4.5-6 kg of agent (dry Agent weight), you can achieve the purpose of anti-corrosion and pest control. Because this kind of medicament is easy to be lost in water, it should only be used on wooden components that are not subject to moisture. For wood components that are susceptible to moisture, oil-soluble pentachlorophenol and lindane mixture should be used. Coating the surface with antiseptic insecticides or dipping into the pores of cells can significantly improve their durability. Commonly used agents for building wood structures and components include coal tar anti-corrosion oil, arsenious acid, chlordane, etc., but these agents easily cause environmental pollution. High-efficiency and low-toxic agents include: Mirex, phoxim, pyrethrum, etc. The construction method is the most common spraying on the surface of the material, and the dip injection method (including pressure dip injection and normal pressure dip injection) is better. The more realistic and promising measures are the thixotropic pore pressure method that is applicable to the site and flexible construction. Proper anti-corrosion treatment can increase the durability of wooden structures and components under adverse conditions by more than ten times or even dozens of times. The effect is very significant. Fire prevention The fire resistance of wooden structures and components is mainly determined by the fire resistance limit, and according to To meet the fire resistance requirements of buildings, measures to improve the fire resistance of wood components shall be adopted. The fire resistance limit of wooden components refers to the burning of a certain component in a special furnace according to the flame of the simulated fire temperature (700 ～ 1000C) from the beginning to the loss of its original function (the load-bearing component is the loss of the bearing capacity) time. It can be seen that wood components have certain fire resistance, especially those with large cross-sections. This is because wood is composed of hollow cells and has a low thermal conductivity. And wood
