Post Construction Termite Treatment in Kenya: Protecting Completed Buildings

The majority of properties in Kenya were built without any form of termite protection. Whether because the builder skipped pre-construction treatment to cut costs, because the owner was unaware of the requirement, or because the building predates modern termite treatment standards, millions of Kenyan homes and commercial buildings stand on soils that harbour active or potentially active subterranean termite colonies.

Post construction termite treatment exists precisely for this reality. It is a proven, highly effective method for creating a chemical soil barrier around and beneath a completed building - one that prevents termites from reaching the structure's timber elements, regardless of how long the building has already been standing.

Pestraid Kenya performs post construction termite treatment on hundreds of existing buildings every year across Nairobi, Mombasa, Kisumu, and Nakuru. This guide covers the complete process, the chemicals used, how long it lasts, and what it costs.

What Is Post Construction Termite Treatment?

Post construction termite treatment (also known as remedial soil treatment or retrospective barrier treatment) is the application of a registered termiticide into the soil surrounding and beneath a fully completed building. The treatment creates a continuous chemical zone in the soil through which termites cannot pass without picking up a lethal dose of the active ingredient.

This is distinct from pre-construction termite treatment, which is applied to bare soil before concrete slabs and foundations are poured. Post construction treatment must work around an existing structure - through drilling, trenching, and injection - rather than treating open soil directly.

Why Post Construction Treatment Is Necessary Even in Seemingly Intact Buildings

Here is a critical insight that most property owners miss: termites can be actively feeding inside a building's timber elements for years before any external evidence appears. The workers operate in concealed galleries within wall cavities, beneath floor boards, and inside roof trusses - areas that never see daylight and are never visually inspected.

By the time you notice:

• Sagging or spongy areas in your timber floor
• Door frames that suddenly stick or crack at the corners
• Paint peeling on skirting boards from the inside
• Visible mud tubes emerging from a wall or skirting

...the colony has been present for a significant period. Post construction treatment stops the ongoing damage and prevents further colonization.

Read our guide on Signs of Termite Infestation in Kenya Homes to identify what to look for before calling us.

The Step-by-Step Post Construction Treatment Process

Pestraid Kenya's post construction termite treatment follows a structured protocol that varies based on the building's construction type and the specific areas requiring treatment.

Step 1: Pre-Treatment Inspection and Survey

Before any chemical is applied, a thorough termite inspection is conducted. Our technician maps:

• All areas of existing termite activity and damage
• The construction type (slab-on-ground, suspended timber floor, or combination)
• The perimeter accessibility - whether concrete paths, decking, or garden beds obstruct access
• Plumbing entry points, expansion joints, and foundation details

This survey determines the specific treatment strategy and allows us to produce an accurate, fixed-price quote.

Step 2: External Perimeter Trenching

Where the ground around the building is accessible:

1. A trench is cut adjacent to the external foundation walls, approximately 150-300mm wide and 300mm deep
2. The trench floor and walls are thoroughly saturated with a registered termiticide at the specified label rate
3. The soil is backfilled in layers, each layer treated with termiticide, creating a vertical treated zone from the surface down to the foundation footing level
4. A horizontal treated zone is also created along the top of the backfilled trench

Step 3: Drilling Through Concrete Surfaces

Where concrete paths, driveways, verandas, or patios adjoin the building and prevent trenching:

1. Holes are drilled at 300-500mm intervals through the concrete surface
2. A high-pressure injection rod is inserted into each hole
3. Termiticide is injected at pressure into the soil beneath, creating a treated zone under the slab at foundation level
4. Holes are sealed with concrete plugs after treatment

Step 4: Internal Sub-Floor Treatment (Where Applicable)

For properties with suspended timber floors or internal concrete slabs:

1. If a crawl space exists, it is entered and the soil beneath the floor is directly treated
2. For solid slab construction, holes are drilled through internal floor finishes at critical points (around plumbing penetrations, along internal wall lines, and in high-risk rooms) and termiticide is injected beneath the slab

Step 5: Wood Treatment of Infested Timbers

Where active infestation is confirmed in specific timber elements, a supplementary boron-based wood treatment or contact termiticide injection is applied directly to the affected timber, killing workers in contact and providing residual protection to the wood itself.

Step 6: Documentation and Warranty

After completion, Pestraid Kenya provides:

• A detailed treatment completion report with a map of all treated areas
• Product data sheets for all chemicals applied
• A written treatment warranty (typically 3-5 years)
• A schedule for follow-up inspection visits within the warranty period

Chemicals Used in Post Construction Termite Treatment in Kenya

Pestraid Kenya uses only Pest Control Products Board (PCPB)-registered termiticides. The two most effective and widely used active ingredients in Kenya for post construction applications are:

Fipronil (e.g., Termidor): A highly effective non-repellent termiticide with an exceptional Transfer Effect. Termites that contact the treated soil carry Fipronil back to the colony on their cuticle and through trophallaxis (food sharing), systematically eliminating the queen and the entire colony over weeks. Read more in our guide on Termidor Termite Treatment.

Imidacloprid (e.g., Premise, Confidor): Another registered non-repellent systemic termiticide widely used across Kenya. Works through a similar transfer mechanism. Read more in our Premise Termite Treatment guide.

Both chemicals bind tightly to soil particles, are environmentally stable at the application depth, and pose minimal risk to humans, pets, and non-target organisms when applied by a licensed professional.

How Long Does Post Construction Treatment Last?

A professionally applied post construction soil barrier treatment using registered products will remain effective for:

• Fipronil-based barriers: 5-8 years under typical Kenyan soil and climate conditions
• Imidacloprid-based barriers: 3-6 years

Annual inspection visits (included in the warranty period) allow Pestraid Kenya technicians to detect any degradation in the barrier and apply supplementary treatments where needed before the warranty expires.

Post Construction Treatment Cost in Kenya

Post construction treatment cost is calculated based on:

• Linear perimeter of the building (external walls measured in running metres)
• Slab construction type and drilling requirements
• Property size (total floor area)
• Severity of any existing infestation

For a detailed cost breakdown, read our guides on Termite Treatment Cost in Kenya and Termite Control Cost in Nairobi.

Is It Too Late to Treat My Building?

No. It is never too late to apply post construction termite treatment. Even if a building has an active infestation, treatment will eliminate the foraging workers entering the building and, through the Transfer Effect of non-repellent termiticides, ultimately destroy the colony. Pestraid Kenya has successfully treated buildings that have had active infestations for over a decade. The key is to act quickly once the infestation is identified.

The post construction termite treatment service offered by Pestraid Kenya is available for all residential and commercial property types. Explore our related services including commercial termite control.

Frequently Asked Questions

Can post construction treatment be applied to any building? Yes, in principle. The specific technique adapts to the construction type. All building types - concrete slab, suspended floor, stone, brick, or steel-frame - can be treated.

Will drilling damage my floor tiles? Our technicians use specialized diamond drill bits to create the minimum necessary hole size. Holes are carefully sealed with matching grout or concrete plug after treatment. Damage is minimal and is repaired as part of the service.

How long does the treatment process take? For a standard three-bedroom house, allow one full working day. Larger or more complex properties may require two days.

Does the treatment have any smell? Modern non-repellent termiticides have minimal odour. Any slight smell dissipates within a few hours after application.

Is treatment safe for children and pets? Yes. Once the treated soil has dried and any drill holes are sealed, re-entry is safe. We advise staying away from areas being actively worked on during treatment.

Schedule Your Post Construction Termite Treatment Today

If your building has never been treated, or if the last treatment warranty has expired, schedule a professional inspection and treatment with Pestraid Kenya today. Browse all our termite treatment services or read more on our blog.

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Contact Pestraid Kenya

Pestraid Kenya - Post Construction Termite Treatment Specialists across Kenya.

• 📞 Phone / WhatsApp: 0710 907 628
• 📧 Email: sales@pestraid.co.ke
• 🌐 Website: www.pestraid.co.ke
• 📍 Areas Served: Nairobi, Mombasa, Kisumu, Nakuru, Thika, and all major Kenyan towns