The methods of termite proofing mentioned below are applicable to the subterranean termites only. It causes serious damage to the buildings. The dry wood termites can be effectively damage to the buildings. The dry wood termites can be effectively controlled by using preservative treated timber. The methods of termite proofing can be classified into the following two groups
- Soil treatment with chemicals
- Structural barriers.
Soil treatment with chemicals
The soil insecticides are thoroughly mixed and well spread in soil so as to provide an effective chemical barrier for termites. The various patented chemical insecticides such as DDT, BHC, PCP,etc. are available. But the following chemicals in oil solution or preferably water emulsion have proved to be successful.
- Aldrin……………………0.5 percent
- Chlordane……………1.0 Percent
- Dieldrin………………..0.5 Percent
- Heptachlor……………0.5 Percent
The above concentrations are by weight. All chemicals are chlorinated hydrocarbons. They are insoluble in water and hence they are not leaches out by the subsoil water. The application of these chemicals serve as a chemical barrier between the building and the ground and this method has proves to be the most effective method of termite proofing.
The soil treatment with chemicals should start when the foundation trenches are ready to take mass concrete in foundation. The laying of mass concrete should start when the chemical emulsion has been absorbed by the soil and the surface is dry. The treatment should not be carries out when it is raining or when the soil is wet with rain or subsoil water.
The chemical solution should be uniformly spread and for this purpose, a suitable hand operated compressed air sprayer or vessel containing water should be used.
All the soil insecticides are poisonous. These will be adverse effects if these chemicals are absorbed through skin, inhaled as vapor or swallowed. It is therefore necessary to follow strictly the precautions mentioned on the containers of insecticides.
To prevent the entry of termites through walls, the impenetrable physical structural barriers may be provided continuously at plinth level. Such structural barrier may be in the form f a cement concrete layer or metal layer at plinth level. The cement concrete layer coping is 50mm to 75 mm thick and it is preferable to keep it projecting about 50 mm to 75 mm internally and externally. The metal barriers consist of sheets of noncorroding metals such as copper or galvanized iron, having a thickness of about 0.80 mm. The metal barriers are likely to be damaged and may then prove to be ineffective against termites
Principles of Termite Control
1. Bridging. It should be seen that a bridge is not formed between any part of the building
and untreated soil.
2. Cost. Once the termites have established themselves in a particular building, it
becomes difficult and costly to remove them completely. It is therefore advisable to give suitable treatment of termite proofing during the construction of the building.
3.Drainage. It is necessary to ensure adequate site drainage as the termites are attracted to moisture. Where possible the concrete or masonry apron must be constructed around the periphery of the building as shown. This prevents seepage of water to the underside of the building. If this is not possible, stone slabs must be provided below the rainwater pipes to help drain away the rain water.
4. Filling Material. Extreme care must be taken in inspecting the filling material or debris
used for reclamation of soil. If it contains termite colonies, the multistory buildings constructed on the reclaimed fall victim to termites.
5.Floor Joints. The suitable joint fillers or metal strips may be used to make floor joints termite proof.
6. Filling Material. Extreme care must be taken in inspecting the filling material or debris
used for reclamation of soil. If it contains termite colonies, the multistory buildings constructed on the reclaimed fall victim to termites
7.Floor Joints. The suitable joint fillers or metal strips may be used to make floor joints termite proof.
- Foundations. It is not possible for termites to enter or penetrate through dense cement concrete foundations or other solid foundations. •For such foundations, it is not necessary to start the treatment from the bottom of excavation as shown. It is sufficient to treat the soil up to 500 mm below ground level or up to the bottom of the plinth beam, if this level is less than 500mm. The construction of foundations should therefore be carried out with superior quality materials and better workmanship.