The decision to specify pre-construction termite treatment in a BOQ versus deferring protection until after handover is one of the most consequential calls a builder, architect, or homeowner makes for a Karachi property. It affects 20 to 30 years of structural integrity, the cost of remediation, the validity of any warranty issued by a licensed pest control operator, and — in coastal pockets of Karachi where the water table sits within two metres of grade — whether a wooden door frame survives its second monsoon. We have treated soil under raft foundations in DHA Phase 8 before the lean concrete was poured, and we have drilled through twenty-year-old marble plinth in old PECHS bungalows to reach soil colonised by Coptotermes heimi. The chemistry, the application rates, and the warranty terms are not the same. This page explains both methods in the detail builders and informed homeowners need to specify the right work and refuse the wrong shortcuts.
What pre-construction termite treatment actually does
Pre-construction termite treatment, often called soil pre-treatment or anti-termite soil treatment (ATT), is the creation of a continuous chemical barrier in the soil that surrounds and underlies a building, applied in stages that follow the construction sequence. No termite reaches the structural timber, the door frames, the wardrobes, the kitchen cabinetry, or the cable insulation without first crossing a treated soil zone where it picks up a lethal dose. The execution is anything but simple, because the barrier must be unbroken — a single untreated column of soil under a plumbing chase is enough to compromise the entire envelope.
We follow the protocol broadly aligned with IS 6313 [1] Part 2, which Pakistan's organised builders adopt by reference in the absence of a stand-alone PS code. The treatment is delivered in four stages.
Stage one — bottom of foundation trenches and column pits. After excavation and before any blinding concrete is poured, we flood the bottom of trenches and pits with standard fipronil [2], mixed at the label rate, at 5 litres of working solution per square metre. Owners who want the longer warranty take the Agenda (fipronil) upgrade instead; the stages and volumes do not change, only the product and the warranty term.
Stage two — refilled earth around the foundation. After foundations are cast and the trench is backfilled to plinth level, the vertical faces of the backfill against the foundation are treated at 7.5 litres per square metre. This is the layer that intercepts subterranean termites foraging horizontally from neighbouring plots, which in Karachi is the most common ingress route in dense DHA and Bahria blocks.
Stage three — plinth fill and apron. Before the plinth slab or the floor screed is laid, the entire compacted earth fill is treated at 5 litres per square metre. This is the single most important application: it places the chemical barrier directly beneath the slab. The same non-repellent fipronil goes into the plinth fill, so foragers that reach the slab edge pick up the active and carry it back to the colony instead of being deflected to hunt for a gap.
Stage four — perimeter on completion. After the building is finished and external grade is established, a perimeter trench 300 mm deep and 150 mm wide is excavated against the plinth wall, treated at 7.5 litres per linear metre of trench, and backfilled. This layer defends against future colonies establishing in landscape soil.
The total chemical loading on a 200 square metre footprint averages 1,800 to 2,400 litres of working solution across the four stages — worth remembering when a contractor proposes to discharge the entire pre-construction obligation in a single afternoon for PKR 25,000.
What post-construction termite treatment does
Post-construction treatment is what we install when the building already exists and either an active infestation is present, a neighbour's infestation is advancing, or the owner wants a protective barrier the original builder did not specify. The mechanism differs because we cannot lay chemical under an existing slab — we have to reach the soil beneath it through the concrete. A full drill-and-inject barrier around the whole building is termite proofing and carries the same warranty as pre-construction work: seven years with standard fipronil, ten with the Agenda upgrade. Treating only the active zone, without a full barrier, is termite control and carries a one-year warranty.
Drill-and-inject through the plinth. We mark a 300 mm grid along the internal face of every external wall and along internal walls that abut earth-filled spaces. At each grid point we drill a 12 mm hole at a 45-degree angle through the slab and plinth concrete until the bit emerges into the soil fill below. Each hole receives 1 litre of standard fipronil working solution, mixed at the label rate, injected under low pressure with a hand pump until the soil refuses further flow. The holes are sealed with a colour-matched cementitious filler. On marble or imported tile, we drill through the grout line instead of the tile.
Fipronil is our active for post-construction, exactly as it is for pre-construction, because of its non-repellent mode of action. Coptotermes heimi foragers walk through treated soil without detecting the chemical, pick up a sublethal dose, and carry it back to the nest where horizontal transfer through trophallaxis and grooming kills the colony. A repellent active would be wrong here — it would push surviving foragers to find an untreated route, and post-construction barriers always have small gaps.
Perimeter trench. External to the building, we excavate the same 300 mm by 150 mm trench against the plinth and apply standard fipronil at 5 litres per linear metre, then backfill. Where the perimeter is paved, we drill at 300 mm centres through the paving and inject the same volume per hole.
Wood treatment for visible infestation. Where mud tubes, exit holes, or hollow-sounding timber show active infestation, we drill 6 mm holes into the affected member at 150 mm intervals and inject a wood treatment until the timber refuses further uptake, with a surface spray to catch surface-foraging workers. Heavily damaged structural members are replaced — chemical treatment does not restore lost cross-section. Wood treatment on its own is termite control, with a one-year warranty.
For homeowners trying to read the warning signs early, our termite signs guide covers the visual indicators we look for during a post-construction survey.
Cost comparison
Pre-construction is dramatically cheaper per square foot than post-construction, because soil access is free during construction and expensive afterwards. The numbers below are our 2026 rates for residential work in Karachi; commercial rates differ.
| Parameter | Pre-construction | Post-construction |
|---|---|---|
| Per square foot cost (covered area) | PKR 18 to 28 | PKR 55 to 90 |
| Warranty offered | 7 years (10 with Agenda) | 7 years (10 with Agenda) for a full barrier; 1 year for spot control |
| Treatment time (1,800 sqft house) | 4 site visits over construction period | 1 to 2 days |
| Disruption to occupants | None — site is empty | Moderate — drilling, filler curing |
| Primary active | Standard fipronil (Agenda for the 10-year upgrade) | Standard fipronil (Agenda for the 10-year upgrade) |
| Application rate | 5 to 7.5 L/m² per stage | 1 L per drill hole, 5 L/linear m trench |
| Efficacy against subterranean termites | Excellent — continuous barrier | Good — barrier with engineered penetration points |
| Re-treatment trigger | Major plumbing excavation | Annual inspection finding |
A 1,800 sqft ground-floor footprint specified pre-construction costs the builder PKR 32,400 to 50,400 for a seven-year warranty (ten with the Agenda upgrade, quoted on request). The same footprint, treated post-construction after an infestation appears in year six, costs the owner PKR 99,000 to 162,000 for a full drill-and-inject barrier carrying the same warranty term — and that excludes the cost of replacing door frames, wardrobe back panels, and parquet the colony has already consumed. Line-item costs for both methods are published in our termite treatment cost guide and the 2026 pest control prices page.
The cost differential is the entire commercial argument for specifying pre-construction treatment on every new build in Karachi. The argument against — that the owner does not want to add cost at construction stage — does not survive contact with the remediation invoice.
Warranty implications
We issue two distinct warranty products tied directly to the scope of work, and the terms differ for substantive reasons that builders should understand before they market a property.
Termite proofing warranty — 7 years, or 10 years with Agenda. For pre-construction work it is issued in the name of the original builder or the first owner, transferable on sale of the property up to once. Covers the entire structure against subterranean termite ingress (Coptotermes heimi and Microcerotermes species, which together account for over 95% of structural termite damage in Karachi). Includes an annual inspection at no charge and a single mid-term spot re-treatment if the inspection finds barrier degradation. Voided by major plumbing or electrical excavation that breaches the soil envelope and is not re-treated within 30 days, addition of an unconnected outbuilding inside the protected perimeter, failure to attend the annual inspection for two consecutive years, or landscape modification that raises external grade above plinth.
A full post-construction drill-and-inject barrier around an existing building is also termite proofing and carries the same seven-year term (ten with Agenda). It is issued in the name of the owner of record at treatment date and covers termite ingress through the treated perimeter and plinth grid. Excludes ingress through zones left out of the barrier, which on some jobs include first-floor cantilever balconies on earth-filled support, untreated rooftop wooden structures, and any internal courtyard the owner declined to include at quotation. Voided by third-party drilling that breaches the chemical grid without re-injection, flood submerging treated soil for more than 48 hours, or failure to attend the annual inspection.
Termite control warranty — 1 year. Treating an active infestation without a full barrier — a single room, a planter wall, infested wooden members — carries a one-year written warranty on the treated zone. It is not extended by an AMC. The line sits there for a plain reason: a spot treatment leaves the rest of the slab open, so a colony can find another way in that we never treated. If you want long-term cover, the route is a full barrier, not a longer promise on a partial job.
When pre-construction is the only right answer
We tell builders to specify pre-construction treatment without exception in five scenarios.
New residential build in DHA, Bahria, Gulshan, North Nazimabad, or any plot within 5 km of Korangi Creek or the Lyari River. The combination of historic Coptotermes heimi activity in adjacent plots and seasonal high water table makes post-construction remediation in these areas a near-certain future cost.
Any project with significant timber in the specification. Solid wood door frames, parquet or engineered flooring, built-in wardrobes with timber backs, MDF-lined dry kitchens, and decorative panelling all represent cellulose targets. If the BOQ specifies anything beyond aluminium or uPVC joinery, soil pre-treatment is not optional.
Buildings with raised plinth on earth fill. Karachi's preference for 600 mm to 900 mm of plinth fill above natural grade creates an ideal subterranean termite habitat directly under the slab — warm, moist, undisturbed, and rich in organic content. Without a chemical barrier at the fill-slab interface, this is a colony in waiting.
Properties with shared boundary walls to existing infested structures. If a neighbouring property has a known termite history, the new build inherits the colony pressure from day one. Pre-construction treatment along the shared boundary is the only effective intervention.
School, hospital, hotel, and commercial kitchen projects. Buildings with occupant density and 24-hour operation cannot tolerate post-construction drilling during occupancy. Pre-construction at PKR 22 per square foot is overwhelmingly cheaper than a future closure for remediation.
When post-construction is sufficient
There are properties where post-construction treatment is genuinely the right answer, not a compromise.
Existing structures with no termite history and conservative finishes. A 1990s apartment block with terrazzo floors, aluminium joinery, and steel kitchen cabinetry in a low-pressure locality may genuinely not need pre-emptive treatment. Annual inspection and defensive perimeter treatment at the first sign of activity is proportionate.
Renovation that retains the original slab. When an owner gut-renovates but does not break the structural slab, there is no pre-construction phase. The right intervention is a comprehensive drill-and-inject grid through the existing slab before the new finishes are laid, executed during the renovation when access is unobstructed.
Single-room or partial-area treatment in response to a localised infestation. Where the infestation is confined to one identifiable zone — a planter wall, a single wardrobe with a wet leak history — post-construction treatment of that zone with a defensive perimeter is sufficient, provided annual inspection confirms the rest is clean. This is termite control, so it carries a one-year warranty.
Heritage properties where structural intervention is prohibited. Listed buildings where drilling through historic floors is not permitted on conservation grounds require a more limited approach: perimeter trench treatment, wood injection of affected members, and intensive inspection. The warranty terms reflect the limited barrier.
Common builder shortcuts to avoid
We will name the shortcuts because the building trade in Karachi tolerates them and the cost is borne by the owner years later.
Single-stage treatment. A contractor proposes to "do the termite" in one visit, usually after the slab is poured. This omits the foundation bottom and the backfill faces, producing a partial barrier that fails wherever the missing stages would have closed the envelope. We refuse this scope and recommend owners do the same.
Dilution below specification. The active concentration on the can is meaningless if the contractor adds twice the specified water at site. We have seen a termiticide nominally mixed at the label rate delivered at roughly a third of it because the operator wanted to stretch the chemical across two sites. The visual result during application is identical. The result in year five is a building with no barrier.
Substitution with cheaper actives. Cypermethrin 10 EC and deltamethrin 2.5 EC are sold as "termite spray" because they are cheaper per litre than the IS 6313-compliant actives. Both are excellent contact insecticides for above-ground pests, both have soil persistence measured in weeks rather than years, and neither belongs in a soil pre-treatment specification.
Omitting expansion joints, plumbing penetrations, and column-slab junctions. These are the precise locations where termites enter, and the precise locations skipped by untrained operators. A proper specification calls out every penetration explicitly: every floor drain, soil pipe, conduit riser, and expansion joint receives an additional 1 litre of working solution before the slab is finished.
Confusing soil treatment with "termite-proof" paint or boric salt sprays. No surface coating provides subterranean termite protection. Anyone offering "termite-proof" anything in lieu of soil treatment is selling a different category of product with no efficacy against Coptotermes heimi.
Our process for pre- and post-construction work
For pre-construction projects, we attach our team to the builder's site for the duration of construction. Visit one happens after foundation excavation and before any blinding concrete is poured: we measure the actual exposed area against the BOQ, mix the fipronil working solution on site using a calibrated dosing unit, and apply at the specified rate while the architect's representative records dwell time and coverage. Visit two follows backfill and treats the vertical foundation faces. Visit three is the plinth fill treatment immediately before the floor slab pour. Visit four is the perimeter trench on substantial completion. Each visit produces a signed treatment certificate with date, area, chemical, lot number, and concentration. The four certificates assembled at handover are the basis on which we issue the warranty — seven years with standard fipronil, ten with the Agenda upgrade.
For post-construction projects, we begin with a paid survey: two hours on site with a moisture meter, a borescope for wall cavities, and a torch for the under-stair, rooftop water tank base, and kitchen plinth. The survey produces a written report with a floor plan, every observed infestation indicator, a proposed treatment grid with hole counts and chemical volumes, and a fixed-price quotation. Treatment is delivered in one or two consecutive days, with rooms vacated 24 hours per zone sequenced to allow normal occupancy of the rest of the house. The warranty issues on completion: seven years (ten with Agenda) for a full drill-and-inject barrier, or one year for spot control of a localised infestation.
Saad Danish is directly involved in technical decisions on any site over PKR 200,000 in contract value. More on our standards is on the about Saad Danish page, and the full range of termite services is on the termite control hub.
Builder and architect BOQ checklist
For builders and consulting architects writing a pre-construction termite treatment line into a BOQ, here is what to specify if the work is to be done properly.
- Specify IS 6313 Part 2 compliance by reference, with the four-stage application sequence written into the scope.
- Name the active by chemical name and require it at the manufacturer's label rate. "Fipronil, applied at the label rate" leaves no room for substitution with a cheaper repellent.
- Specify application rate per stage in litres per square metre or per linear metre — 5 L/m² for plinth fill, 7.5 L/m² for vertical foundation faces, 7.5 L/linear m for perimeter trench.
- Require the contractor to provide a treatment certificate signed at each stage, with date, area, chemical lot number, and concentration recorded.
- Require notification 48 hours before each stage so the architect or owner's representative can attend.
- Require sample retention — a 100 ml sample of the prepared working solution held at site in a labelled bottle for the duration of construction, available for independent laboratory testing if required.
- Specify treatment of every floor drain, soil pipe penetration, conduit riser, and expansion joint with an additional litre of working solution poured directly around the penetration before slab finishing.
- Require the warranty document — seven years for standard fipronil, ten for the Agenda upgrade — to be issued in the name of the first owner with a transferability clause for the first resale.
- Tie 50% of the line-item payment to the issue of the warranty document at handover, not to the apparent completion of the spray work.
Book pre- or post-construction termite treatment with NFS
We work directly with builders, architects, project managers, and owners across Karachi. For pre-construction work, contact us as soon as foundation drawings are issued for tender — we provide a no-charge specification review before the BOQ is finalised. For post-construction work, the same number books the survey, and the written report follows within 48 hours.
Nest Fumigation Services
Plot #14, 2/1 2nd Gizri Street, DHA Phase 4, Karachi 75500
Phone: +92-311-1101810
Email: contact@nestfumigationservices.com
Hours: Mon–Sat 09:30–20:00, Sun closed
Accreditation: ISO 9001:2015, member KCCI, SPMA, PPMA
Our broader pest control coverage across Karachi is available on the pest control Karachi hub, and the contact form is on the contact us page.
Frequently Asked Questions
Can pre-construction termite treatment be added after the slab is poured?+
No. Once the ground-floor slab is cast, the soil under it is permanently inaccessible without drilling, which is by definition a post-construction intervention. If the builder reaches DPC level without specifying soil treatment, the opportunity for true pre-construction work is gone. The fallback is to install the post-construction drill-and-inject grid before the floor finishes are laid, which catches the soil before any visible damage occurs. A full grid is still termite proofing and carries the same seven-year warranty (ten with Agenda); it simply costs more per square foot than doing the work at plinth stage. We are increasingly called in at this midpoint stage by builders who recognise the omission before the marble goes down.
How long does pre-construction treatment last in Karachi soils?+
Our written warranty on a properly executed pre-construction barrier is seven years with standard fipronil, or ten years with the Agenda upgrade. How long the barrier keeps working past that depends on how much the soil is disturbed and on monsoon water-table movement in coastal districts, which is why we recommend an inspection when the warranty term ends. Re-treatment beyond that horizon is a planned maintenance event, not a failure event.
What's the difference in chemical between pre and post-construction work?+
At NFS there is no difference. Both pre- and post-construction proofing use standard fipronil, or Agenda for the ten-year upgrade, because the goal in both cases is a non-repellent barrier: foragers cross treated soil without detecting it and carry a lethal dose back to the colony. That matters most after construction, because treated zones in drill-and-inject work always have small gaps (the spacing between drill holes, the joint between perimeter trench and apron), and a repellent active would simply push the colony through those gaps. What differs between the two is access and cost, not chemistry.
Is pre-construction termite treatment legally required in Karachi?+
Pakistan has no national building code mandating pre-construction termite treatment, and Karachi's municipal bye-laws do not require it. The IS 6313 reference we use is an Indian standard adopted voluntarily by organised builders. In practice, banks financing construction increasingly require it as a condition of disbursement, particularly for projects over PKR 50 million, and major insurance underwriters offer reduced premiums on buildings with a documented treatment certificate. The financial system has begun to enforce what the building code does not.
Does post-construction drilling damage the floor finish?+
The 12 mm drill hole, sealed with a colour-matched cementitious filler, is invisible on most floor types within a week. On terrazzo and grey concrete the colour match is straightforward. On polished granite and high-gloss marble the seal is visible under angled light, so we drill through grout lines when grid spacing permits. On wood-finished floors we lift the affected boards rather than drill through them, treat the slab below, and reset the board. The owner sees no permanent change to the floor in 95% of jobs.
What's the right grid spacing for post-construction drill-and-inject?+
IS 6313 calls for 300 mm centres along internal faces of external walls and along both faces of internal walls abutting earth-filled spaces. Tighter spacing — 200 mm or 150 mm — is required where active infestation is confirmed, or where soil fill is unusually dry or sandy and unlikely to transmit chemical laterally. Wider spacing is occasionally proposed by competitors to reduce labour cost, but at 450 mm or 600 mm centres the soil between holes is functionally unprotected, and the warranty cannot legitimately issue.
Will pre-construction treatment protect against drywood termites?+
No. Pre-construction soil treatment is a barrier against subterranean termites — Coptotermes heimi and Microcerotermes that nest in soil and forage upward. Drywood termites (Cryptotermes species in Karachi) nest entirely within wooden members and never contact the soil. They enter via flight as winged reproductives and establish colonies inside roof trusses, door frames, and furniture. Protection against drywood termites is a wood-treatment activity — treatment of timber before installation, or fumigation of infested members after detection. Both regimes are separate products requiring separate scoping.
How soon after pre-construction treatment can construction resume?+
Each stage has its own resumption time. Stage one (foundation bottom) requires 24 hours of dwell before blinding concrete is poured, so the emulsion penetrates the soil rather than being displaced. Stage two (backfill faces) requires 4 hours before earth is placed over the treated faces. Stage three (plinth fill) requires 24 hours before the floor slab is poured. Stage four (perimeter) requires 12 hours before landscaping. Total delay added to construction is roughly three working days across the full build — negligible against the structural benefit.
Related services from Nest Fumigation Services
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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