Termite proofing is a barrier-geometry problem before it is a chemical one. The termiticide matters, and we will get to it, but what decides whether a building stays protected through its warranty term is whether the treated zone under and around it forms one continuous envelope. Hole diameter, hole spacing, injection volume, and the outside trench are the four variables that define that envelope. A single unreached 40 cm run of foundation is the difference between a treated building and a building with a gap in it, because a Coptotermes heimi foraging gallery does not need more than a crack's width to pass through.
This page walks through the process in the order it happens on site, in enough detail that you can stand next to any contractor, ours included, and see whether the work is being done or being performed. For which product you need in the first place, start at the termite proofing pillar; for what it costs, the figures below trace to our termite treatment cost guide.
Step 1: Inspection and marking out
Every job starts with a survey, not a drill. The technician maps the plinth perimeter, wet areas, expansion joints, the points where utility pipes penetrate the floor, and any existing mud tubes or damage. In Karachi's building stock the highest-risk runs are almost always the same: the kitchen and bathroom wet walls, the base of the staircase, and the joint where a later extension meets the original slab. Those joints move, they crack, and they are the motorway into the building.
The survey ends with the treatment lines physically marked. If a team arrives and starts drilling without marking out, the barrier geometry is being improvised, and improvised geometry has gaps.
Step 2: The drilling grid, and why the spacing is the job
Along every marked line, holes of 12 mm diameter are drilled at roughly 30 cm centres at the wall–floor junction, angled to reach the soil or fill beneath the slab. Those two numbers are not decoration. The termiticide injected into each hole spreads laterally through the soil in a roughly circular plume; at about 30 cm spacing the plumes from adjacent holes overlap, and overlapping plumes are what make the barrier continuous. Widen the spacing to save drilling time and the plumes stop meeting: the result is a dashed line, not a solid one, and termites find the dashes.
Drilling is the loud, dusty, unglamorous half of proofing, and it is the half most often shaved. Counting holes against a tape measure is the single fastest audit a homeowner can run.
Step 3: Injection, at 5 litres per square metre
Each hole is injected until the dose for that run is delivered. Our working rate is 5 L/m² of emulsion, mixed from standard fipronil [1] at the label rate, or from Agenda, a fipronil termiticide, on the 10-year upgrade. The mixing arithmetic matters because it is where dilution-shaving hides: a tank mixed at half strength looks identical coming out of the lance, passes every visual inspection, and produces a barrier that degrades years early. We mix at the vehicle, in the open, and the concentrate bottles used on your job stay on site until the work is signed off. Ask any contractor to show you the same.
Fipronil is non-repellent: termites tunnel through the treated zone without detecting it, pick up a lethal dose, and transfer it through the colony by contact and grooming. That transfer effect is why a continuous low-dose envelope outperforms a strong-smelling repellent barrier with gaps.
Step 4: The outside trench
Where the building has exposed external foundation, a trench roughly 15 cm wide is cut along it, flooded at the same 5 L/m² rate, and backfilled with the treated soil. The trench connects the sub-slab plumes to the external soil, closing the envelope from outside. Skipping the trench on "just the back wall" because there is a flower bed in the way is the most common gap we find when re-treating other firms' failed jobs. The flower bed is precisely why the trench matters there; irrigated soil against a foundation is prime foraging habitat.
Frequently Asked Questions
What does the process look like for new construction?+
For a building under construction the same chemistry is applied in stages instead of through drilled holes: the foundation pits and trench bottoms are treated before concrete, the compacted fill under the slab is flooded before the polythene membrane and floor go down, and the external perimeter is trenched last. The staging is covered in depth on our pre-construction treatment page, and the choice between doing this now or retrofitting later is exactly the trade examined in pre vs post-construction treatment. The one-line version: treating soil before the floor exists costs a fraction of drilling through that floor afterwards, which is why the process is written into IS 6313 [2], the subcontinental standard our staging follows. We keep a plain-language walkthrough of that standard in our IS 6313 explainer.
How long does termite proofing take?+
A typical 120 sq yd Karachi house takes one working day: survey and marking in the first hour, drilling most of the morning, injection and trenching through the afternoon, and sealing last. Larger bungalows and buildings with multiple extensions run to two days. Anyone quoting two hours for a full-perimeter retrofit is not planning to drill at 30 cm centres. Re-entry is the same day once treated areas are dry, since the work is at floor level and the emulsion is bound in soil, not airborne.
What do the drilled holes look like afterwards?+
Sealed. Every 12 mm hole is plugged with cement slurry or colour-matched grout after injection. The finished job should be visible only as a faint dotted line at the skirting if you go looking for it. Unsealed holes are not just cosmetic negligence; they are open routes past the barrier you just paid for.
What does a shortcut physically look like?+
Three things, in declining order of frequency. Holes at 60–90 cm spacing instead of 30 cm: count them. Injection by "walking the lance" without metering volume, which under-doses every hole: the tank going back onto the vehicle still half full is the tell on a job priced for 5 L/m². And a missing external trench wherever the ground is inconvenient. None of these are visible a week later, which is why the audit has to happen on the day.
When should proofing wait rather than be bought?+
Against our own interest: there are jobs we tell customers to postpone. If flooring, plumbing, or plinth repair is planned within the next year, do that first; cutting into a treated slab afterwards punches holes in the barrier you just paid for, and the re-treatment of those cuts is an avoidable cost. If the plinth itself is cracked or the damp-proof course has failed, repair precedes proofing, because a barrier injected into a structure that is about to be broken open is money half wasted. And if the property is a rental you are leaving within the year, a targeted treatment of active infestation is usually the honest recommendation, not a full envelope.
What does the treatment cost, and what does the warranty cover?+
Pre-construction proofing runs PKR 18–35 per sq ft covered area; the worked example on our cost pillar is a 2,000 sq ft build at PKR 25, landing at PKR 50,000. A residential inspection is PKR 2,500–4,000, credited against treatment if you proceed. Full current bands for every treatment type are on the cost guide.
On duration, two different numbers get merged in this market and should not be. The warranty on our proofing is 7 years with standard fipronil, or 10 years with the Agenda upgrade: a written document, explained on our termite warranty page. How long the chemistry stays active in the soil depends on soil disturbance and moisture, which is why we recommend a 12-month re-inspection. The warranty is the paper that answers for the barrier; the chemistry underneath is what does the work. A firm quoting a "15-year treatment" is quoting a number neither the paper nor the chemistry supports.
Is the process safe for a family in the house?+
The emulsion is applied into soil and sealed under cement, not sprayed into living space. Standard practice is to keep children and pets off treated ground-floor areas until sealing is complete, ventilate normally, and re-occupy the same day. The broader treatment philosophy, including where soil barriers are the wrong tool entirely, is on our termite control overview.
If you want the process above run on your own site, or you want us to audit a barrier someone else installed, our team surveys across Karachi. Bring the tape measure; we are happy to be counted.
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Saad Danish is a co-founder and director of Nest Fumigation Services Private Limited, a licensed pest-control and fumigation company based in DHA Phase 4, Karachi. He oversees the company's administration, client services, and marketing, working alongside NFS's technical team to deliver residential and commercial pest management across Karachi — from termite proofing and general pest control to HACCP and Sindh Food Authority compliance programmes for food, warehouse, and industrial clients. Nest Fumigation Services is ISO 9001:2015 certified and a member of the SPMA (Sindh Pest Management Association), PPMA, and the Karachi Chamber of Commerce and Industry.
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