How to Carry Out Anti-Termite Treatment in Existing Buildings?

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Anti-termite treatment is a chemical procedure for soil, masonry, wood, and electrical fixtures to provide the building with a chemical barrier against the subterranean termites before and after construction.

The preventive anti-termite treatment for an existing building is explained in this article. To know about anti-termite treatment during the construction of buildings, click here.

Before jumping into the anti-termite treatment process in an existing building, it is essential to know how to detect termite infestation in a building.

Guide for Termite Detection

1. A bright hand-held electric bulb or a torch is essential to detect the presence of termites. 
2. A portion of the building in contact with or adjacent to soil shall be inspected. 
3. Damp locations, such as toilets and bathrooms, etc., shall be inspected. Particularly, the points where woodwork is embedded in the floor shall be examined.
4. The signs of the presence of termites are through the telltale tubes. 
5. The termites travel in these tubes and eat away the woodwork, leaving the film of paint on the surface, making it challenging to locate the termites.
6. Woodwork should be tapped to check for a hollow sound, which would indicate a termite attack.
7. The new tubes formed by the termites are moist; the old ones are dry and break easily. 
8. These tubes must be gouged out with a knife to destroy the termites.

Post-Construction Treatment

1. Inspection

Before undertaking any treatment, a thorough inspection shall be carried out to determine the extent of an infestation and the routes of entry of the termites into the building.

A study of the foundation structure and the ground floor helps find out the routes of entry of termites from the soil and decide on the mode of treatment.

2. Extermination of Termites in Buildings

1. After studying the infestation in the building, the next step is to eliminate the termites located inside the building.
2. This shall be carried out thoroughly, locating the termites in their hideouts, such as ceilings, behind wooden paneling, inside electrical battens, conduits, switchboards, and similar locations.
3. Recourse may be taken to inject chemicals of recommended concentrations.
4. All precautionary measures shall be followed by the operator while using the chemicals.
5. All traces of termite tubes shall be located and removed so that any fresh infestation that might occur later may be easily detected.
6. The recommended chemicals to be used for the treatment are:
   1. 0.5% Heptachlor emulsifiable concentrate
   2. 1.0% Chlordane emulsifiable concentrate
   3. 1.0% Chlorpyrifos emulsifiable concentrate.

Preventive Measures

1. Soil Treatment

1. The objective of soil treatment is to establish a chemical (toxic) barrier between termites in the soil and the building to be protected.
2. It is carried out by treating the soil adjacent to or under the building with a chemical toxicant that repels or kills the termites.
3. Water emulsion chemicals, as mentioned above, shall be used in soil treatment and applied uniformly at the prescribed rate.

2. Treatment along the Outside of Foundations

1. The soil in contact with the building's external wall shall be treated at a rate of 7.5 l/m² to a depth of 300 mm.
2. To facilitate the treatment, a shallow channel close to the wall face shall be excavated.
3. The chemical emulsion shall be administered towards the exposed wall at the rate of 1.75 liters per running meter of the channel.
4. Rodding shall be done at an interval of 150 mm for uniform disposal of the chemical.
5. In the case of a concrete apron around the wall, holes shall be made in the apron 800 mm apart and 300 mm deep to reach the soil below, and then the chemical solution is pumped at a rate of about 2.25 liters per running meter.
6. In the case of an RCC foundation, the backfill soil in contact with the columns and plinth beams along the external perimeter shall be treated with the chemical solution at a rate of 7.5 l/m².

3. Treatment of Soil Under Floors

The termites seek entry through the cracks formed at the junction of the floor and walls due to concrete shrinkage.

4. Expansion Joints in Floor

The method for treating these locations is by applying chemical treatment wherever such cracks are identified. The chemical is pumped through holes drilled at regular intervals to a reasonable depth until refusal, subject to a maximum of one liter/hole. The holes shall then be sealed.

5. Treatment of Voids in Masonry

1. By squirting chemical emulsion through holes drilled at a downward slope of around 45% in the wall, the movement of termites through the masonry walls can be arrested.
2. Additional holes may be drilled if required, such as under the door, wall corners, and window frames, etc.
3. The treatment holes shall then be sealed.

6. Treatment at Points of Contact with Woodwork

All infested existing works shall be treated by spraying or squirting chemical emulsion at contact points with masonry.

7. Treatment of Wood Work

1. Woodwork that has been damaged beyond repair must be replaced.
2. Infested woodwork, which can be reused, shall be protected with chemical emulsion squirted through inclined holes drilled up to the core of woodwork.
3. The woodwork shall further be painted with one or two coats of chemicals.

Inspection

Regular inspection of the work/installations, particularly during humid and hot seasons, is necessary to avoid further infestation.

FAQs

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