Termites do their damage in silence. By the time a homeowner notices hollow-sounding skirting or mud tubes along a wall, the colony has usually been feeding for months — inside door frames, behind wardrobes, under the flooring. In warm, humid Indian climates the subterranean termite never really goes dormant, which is why termite protection is a calendar discipline, not a one-time purchase.
The most expensive misconception in the market is that a plywood grade protects against termites. It does not. BWR (IS 303) and BWP (IS 710) grades certify boiling-water resistance — a moisture test, not an insecticide. Termite resistance comes from chemical treatment of the soil and the timber, applied at the right stages of construction. Any dealer who claims BWP means no termites is selling, not informing.
This guide covers the three treatment windows — pre-construction soil treatment, pre-carpentry wood treatment, and post-construction drill-fill-seal — the warning signs that mean a colony is active, and the annual checks that keep a home protected after the interiors are done.
The three treatment windows
| Treatment | When | What it does | Limits |
|---|---|---|---|
| Pre-construction soil treatment | Foundation stage, before flooring | Chemical barrier in the soil under and around the building; foraging termites cannot cross it to reach the structure | Only possible during construction; the Indian code of practice is IS 6313 |
| Plinth and junction treatment | During construction, at plinth level | Treats wall-floor junctions, pipe entries and construction joints where termites commonly penetrate | Needs coordination with the civil contractor while work is open |
| Pre-carpentry wood treatment | Before woodwork is fixed — door frames, battens, board edges | Preservative applied to timber so the wood itself resists attack | Only protects surfaces the chemical reaches; hidden faces must be treated before fixing |
| Drill-fill-seal (post-construction) | Any time after handover | Holes drilled along the plinth inside and outside; chemical injected into the soil below the floor | The standard remedial method; protection needs re-application on schedule |
| Preservative polish on woodwork | During interior finishing | Adds a protective layer to exposed wood surfaces | A supplement, never a substitute for soil treatment |
| Baiting systems | Confirmed active infestations | Bait stations that foraging termites carry back to the colony | Slow-acting; a professional programme, not a DIY product |
| Annual inspection | Every year, ideally pre-monsoon | Professional check of plinth, woodwork and damp zones; early colonies caught while small | The cheapest treatment is the inspection that finds nothing |
Pre-construction: the barrier you can never add later
Pre-construction soil treatment is the only termite defence that cannot be retrofitted. While the foundation is open, chemical is applied to the soil under the floor slab and in a continuous band around the plinth, creating a treated zone that foraging termites will not cross. The Indian code of practice for this work is IS 6313, which lays out the stages — foundation pits, backfill, plinth and floor junctions — at which treatment is applied.
Anyone building a new house should confirm this treatment is in the civil contractor's scope, in writing, with the chemical brand and concentration named. It is a small line item against the cost of the structure, and it protects everything built above it for years. Once the flooring is laid, this window closes permanently — every later treatment is a remedial compromise by comparison.
Pre-carpentry: treat the wood before it is fixed
The second window opens during interior work, before a single frame or panel is fixed. Door frames, window frames, wooden battens, and the hidden faces of board edges should receive preservative treatment — by dipping or thorough spraying — before fixing. Treatment after fixing only reaches exposed faces; termites attack from the hidden side, inside the wall chase or behind the skirting, where a post-facto spray never reaches.
This is also the moment to enforce the detailing rules that make treatment last: no wood in direct contact with soil or damp masonry, a clear gap between wooden cladding and the floor where it can be inspected, and all pipe and conduit penetrations sealed. Good detailing plus treated timber is what keeps the annual inspection a formality instead of a rescue operation.
Warning signs: how to know termites are active
Termites rarely show themselves; they show their work. Mud tubes — pencil-thick earthy tunnels — running up walls, plinths or foundations are the classic sign of subterranean termites travelling between soil and food. Wood that sounds hollow when tapped, paint that blisters in lines along a frame, and small piles of discarded wings near windows in swarming season all warrant a professional inspection, not a spray can.
One honest caution: surface sprays kill the termites you can see and scatter the rest deeper into the structure. A visible patch treated with a household spray while the colony thrives behind the wall is the most common way a small problem becomes a big one. Active signs mean calling a licensed pest-management professional for a full inspection and a proper soil or baiting programme.
Treatment costs: what the service covers
Termite treatment is quoted as a service, not a material, and rates vary with property size, soil conditions and whether the job is preventive or a live infestation. What matters more than the headline figure is the scope in writing: which areas are treated, which chemical and concentration, how many visits, and how long the warranty runs. A written warranty with scheduled re-inspections is the real product; the chemical alone is not.
| Service | Typical scope | Usual frequency |
|---|---|---|
| Pre-construction soil treatment | Foundation pits, backfill, plinth and floor junctions (per IS 6313 stages) | Once, during construction |
| Pre-carpentry wood treatment | Door/window frames, battens, hidden board faces before fixing | Once, during interiors |
| Post-construction drill-fill-seal | Interior and exterior plinth perimeter, pipe entries | As prescribed by the chemical maker; often multi-year protection |
| Targeted colony elimination | Baiting or direct treatment of active infestation zones | Until the colony is confirmed dead, then preventive schedule |
| Annual inspection contract | Full check of plinth, woodwork, damp zones; early treatment if found | Every year, ideally pre-monsoon |
Treatment timing verdicts
- Building new: insist on pre-construction soil treatment in the civil scope, in writing, with the chemical named — this window never reopens.
- During interiors: treat all timber before fixing; seal every pipe and conduit penetration; keep wood off damp masonry.
- After handover, no history: a preventive drill-fill-seal around the plinth plus an annual inspection contract is the baseline.
- Active signs (mud tubes, hollow wood): stop, do not spray surfaces — call a licensed professional for inspection and a full programme.
- Near water and damp zones: bathrooms, kitchens and leaky terraces attract termites; fix the moisture and the treatment lasts longer.
- Annual rhythm: one professional inspection every year, ideally before the monsoon when colonies are most active.
- BWP plywood is moisture-graded, not termite-proof — never accept it as a substitute for treatment.
Sources & standards
- IS 6313 — Code of practice for anti-termite measures in buildings (Bureau of Indian Standards): pre-construction soil treatment stages
- IS 303 / IS 710 — plywood grades certify boiling-water resistance (moisture), not termite resistance (Bureau of Indian Standards)
- Drill spacing, treatment timing and inspection practice — commonly cited Indian pest-management trade practice; follow the chemical manufacturer's schedule on site
