Anti Termite Treatment
What is Anti Termite Treatment?
Anti Termite treatment is a chemical treating process that is done to protect a structure against a termite attack. The treatment can be done before and after the construction, it is generally done over foundation soil, masonry structures, wooden structures, and over electrical fixtures.
What is Termite?
Termites, commonly known as white ants cause considerable damage to woodwork, furnishings, etc. of buildings. In some countries, the loss caused due to termites is estimated to be as high as 10% of the capital outlay of the buildings. Anti-termite treatment is, therefore, essential so that losses are either minimize or stopped.
Types of Termite
Termites are of two types :
- Dry wood termites
- Sub-terranean termites.
Dry Wood Termites
Dry wood termites These termites live in dry wood in small colonies, without maintaining any connection with the soil. They are generally found in wet marshy areas. In India, they are found in coastal regions of South India, though their number is low. They reside and work in wooden structures only.
Subterranean termites These termites have their main colonies in the soil, underground. They cannot persist without maintaining any contact with their prime colonies in the soil. However, they travel in the exploration of food, mostly wood and cellulose matter, through shelter tubes or galleries or tunnels in other materials. These tubes are coated with soil around. As they consume wood, secondary colonies are developed there. These termites require dampness areas for their existence. These termites enter the buildings through foundations or from the ground adjacent to the buildings and advance upward through floors destroying everything that comes within their reach. They also travel through cracks and crevices in masonry and joints or cracks in floors.
The procedure of Anti-Termite Treatment
The anti-termite treatment process may be divided into two categories :
- Pre-construction treatment.
- Post-construction treatment.
Pre-Construction Anti Termite Treatment
This treatment is started right at the initial ‘stage of construction of the building,
Pre-construction treatment can be divided into three operations
- Site preparation.
- Soil treatment.
- Structural barriers.
This operation consists of the replacement of stumps, roots, logs, waste wood, and other fibrous matter from the soil at the construction site. This is necessary since the termites grow on these materials. If termite mounds are detected, these should be destructed by use of insecticide solution, consisting of any one of the following chemicals :
Chemical Concentration by weight
- DDT 5%
- BHC 0.5%
- Aldrin 0.25%
- Heptachlor 0.25%
- Chlordane 0.5%
Four liters of the above emulsion in water are required per cubic meter of the volume of the mound. Holes are made in the mound at several places by use of a crowbar and the insecticide emulsion is poured in these holes.
The best and only reliable method to protect buildings against termites is to apply a chemical treatment to the soil at the time of construction of the building. This should be done in such a way that a complete chemical barrier is created between the ground from where the termites come and damage woodwork in the building. An insecticide solution consists of any one of the following chemicals in water emulsion :
Chemical Concentration by weight
- Aldrin 0.5%
- Heptachlor 0.5%
- Chlordane 1%
Out of the above chemicals and several other chemicals, Aldrex 30 H.C. has proved to be the most effective. It has the following advantages : (i) It is highly toxic to termites. (ii) It can easily be applied after dilution with water. (iii) It is insoluble in water. In other words, this chemical will not dissolve in sub-soil water and disappear quickly from the site. (iv) It is effective even many years after application.
One part of ‘Aldrex’ 30 E.C. is diluted with 59 parts of water. This provides an emulsion containing 0.5% aldrin.
The emulsion should be applied evenly either with a watering can or sprayer at the following stages :
Stage 1– In foundation pits, treat the bottom and sides up to a height of about 30 cm. The emulsion required is at the rate of 5 liters per square meter.
Stage 2– The refill earth on both the sides of all built-up walls, for the width of 30 cm and depth of 45 cm approximately. The emulsion required is at the rate of 5 liters per square meter.
Stage 3– Before laying the floor, the entire leveled surface is to be treated at the rate of 5 liters of emulsion per square meter.
The stages of treatment are shown diagrammatically in Fig. 22.1. When used as recommended above, approximately 200 ml of ‘Aldrex’ 30 E.C. would be required to treat one square meter of the covered area.
Post-Construction Anti Termite Treatment
It is a maintenance treatment for those buildings which are already under attack by termites. As stated earlier, the termites, even after entering the building, maintain their contact with their nest or colony in the ground, through shelter tubes or tunnels lined with soil.
This fact is well appropriated in anti-termite treatment. It is essential to carry out an inspection to estimate the magnitude of the spread of termites in the building and to detect the points of entry of termites in the building. These points may be in the near vicinity of columns, basements, steps leading from the ground, bathrooms and lavatories, leaking pipes, drains, etc., and the places where woodwork is embedded in the ground.
In the case of multi-storeyed buildings, lift wells, casing-coverings of electrical wirings, water supply lines, soil pipe, etc. may be the entry points for the termites. these shelter tubes are detected, these should be destroyed after injecting anti-termite emulsion through these.
If the attack is severe, the soil around the building and soil under the floor may be injected with anti-termite emulsion. This treatment may be applied up to a depth of 30 cm below ground level. To prevent the entry of termites through voids in the masonry, 12 mm dia. holes are drilled at 30 cm c/c at the downward angle of 45° from both the sides of walls at plinth level, and the chemical emulsion is pumped into these under pressure. These holes are then sealed.
This treatment of drilling punch holes and pumping chemical emulsion is carried out at critical locations such as wall corners, column bases, place of embedment of doors and windows, etc. Similar holes are drilled in damaged woodwork also and then the oil-based chemical emulsion is pumped into these.