---
title: "Post construction anti-termite treatment"
subject: "Civil Engineering Materials"
chapter: 9
key: "semester_3/civil_engineering_materials:post-construction-antitermite"
source: https://www.bctengineer.com/q/semester_3/civil_engineering_materials/post-construction-antitermite
site: BCT Engineering
---

# Post construction anti-termite treatment

Civil Engineering Materials · Chapter 9: Paint and Varnishes

- Asked in: 2068 Chaitra, 4 marks
- Video: [Post-Construction Anti-Termite Treatment ProcessDrilling & Chemical Injection Process](https://www.youtube.com/watch?v=w7IgvSXjA00) — Hygiene Solution Pest control
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_3/civil_engineering_materials/post-construction-antitermite
- Whole chapter: https://www.bctengineer.com/md/semester_3/civil_engineering_materials/chapter-9

## Question

Explain briefly about post construction antitermite treatment.

## Short answer

Post-construction anti-termite treatment uses chlorpyrifos or imidacloprid emulsion as per IS 6313 (Part 3). Inside, holes are drilled at wall-floor junctions and the chemical is injected under pressure. Outside, a trench is dug, soil treated, and backfilled. Cracks, voids and wood are also injected, with annual inspections to maintain the barrier.

## Answer

**Post-construction treatment** is done in an already built building to kill termites present and to build a chemical barrier outside and inside, as per IS 6313 (Part 3). It uses the same chemicals (chlorpyrifos or imidacloprid emulsion) as the pre-construction method.

1. **Inspection:** Find the entry points, mud tubes, damaged wood and nests.
2. **Treatment of the plinth (inside):** Drill holes of about 12 mm diameter at 300 mm centres along the junction of wall and floor, in the floor next to the wall; inject the emulsion by pressure (about 7.5 litres per running metre) and seal the holes with cement mortar.
3. **Outside soil treatment:** Dig a trench about 300 mm wide and deep along the external perimeter, treat the soil at about 7.5 litres per running metre of trench, and backfill in layers while sprinkling the emulsion.
4. **Treatment of cracks and voids:** Drill and inject the chemical into wall cracks, expansion joints, and behind skirting.
5. **Treatment of wood:** Spray or inject termiticide into wooden frames, and replace badly damaged members.
6. **Nests:** Destroy visible mounds by digging and pouring the chemical.
7. **Follow-up:** Re-inspect yearly; repair any breaks in the barrier.

## Check yourself

The answer's key points as multiple-choice questions, with the correct option and why.

1. What is the aim of post-construction anti-termite treatment?
   A. To strengthen the foundation
   B. To kill termites present and build a chemical barrier in an already built building
   C. To paint the walls
   D. To lower the plinth
   Answer: B. It kills existing termites and creates a barrier outside and inside, as per IS 6313 (Part 3). (Key point: Aim)

2. How are holes made along the wall-floor junction?
   A. About 12 mm diameter at 300 mm centres
   B. About 50 mm at 1 m centres
   C. About 12 mm at 3 m centres
   D. About 25 mm at 100 mm centres
   Answer: A. Holes of about 12 mm diameter at 300 mm centres are drilled, injected and sealed with cement mortar. (Key point: Plinth drilling)

3. How is the soil outside treated?
   A. Concrete is poured
   B. A trench about 300 mm wide and deep is dug, treated at about 7.5 litres per running metre and backfilled
   C. Only the surface is sprayed once
   D. The soil is removed
   Answer: B. A trench along the perimeter is treated at about 7.5 L/m and backfilled in layers with emulsion sprinkled. (Key point: Outside treatment)

4. What follow-up is recommended?
   A. None
   B. Re-paint
   C. Re-inspect yearly and repair breaks in the barrier
   D. Replace all timber
   Answer: C. Re-inspect yearly and repair any breaks in the barrier. (Key point: Follow-up)

## Related in Civil Engineering Materials

- [Importance of anti-termite treatment](https://www.bctengineer.com/question.md?key=semester_3%2Fcivil_engineering_materials%3Aantitermite-importance) — Civil Engineering Materials, chapter 9, asked 4×
- [Anti-termite treatment procedure](https://www.bctengineer.com/question.md?key=semester_3%2Fcivil_engineering_materials%3Aantitermite-procedure) — Civil Engineering Materials, chapter 9, asked 3×

## Related in other subjects

- [Foundation treatment before gravity dam construction](https://www.bctengineer.com/question.md?key=semester_7%2Fhydropower_engineering%3Afoundation-treatment-gravity-dam) — Hydropower Engineering, chapter 4