Termite Treatment for Existing Buildings in Kenya: Your Complete Options Guide

The majority of buildings in Kenya - from modest rental units in Kahawa West to expansive residences in Karen - were constructed without any form of termite treatment. Whether because of cost-cutting, lack of awareness, or the fact that the building predates modern termite treatment standards, millions of Kenyan property owners are living or operating in buildings that have no chemical barrier between the structure's timber and the termite colonies in the surrounding soil.

If your building has never been treated, or if the previous treatment warranty has expired, this guide covers everything you need to know: what treatments are available, how each works, what is involved in the process, how long it lasts, and what it costs.

The Key Challenge: Treating Around a Completed Structure

Termite treatment for an existing building is inherently more complex than pre-construction treatment because the building's concrete foundations, floor slabs, internal walls, and floor finishes prevent direct access to the soil zones that need to be treated. The treatment must reach:

1. The soil immediately adjacent to external foundation walls - the primary entry zone
2. The soil beneath the ground floor slab - where sub-slab galleries run from external colonies into the building
3. The soil around all service penetrations through the slab - plumbing pipes, electrical conduits, drainage sleeves
4. Expansion joints and construction joints in the slab - common termite highways

Pestraid Kenya's technicians use specialized drilling and injection equipment to reach all of these zones even when they are covered by concrete, tiles, or paving.

Treatment Method 1: External Soil Barrier Treatment (Trenching and Injection)

This is the most common and most effective primary treatment method for existing buildings in Kenya.

How it works:

• A trench is excavated adjacent to all external foundation walls (150-300mm wide, 300mm deep)
• The trench and soil are treated with a registered non-repellent termiticide (Fipronil or Imidacloprid)
• Where concrete paving, paths, or driveways prevent trenching, holes are drilled through the concrete at 300-500mm intervals and termiticide is injected at pressure into the soil beneath
• All drill holes are sealed after treatment

Best for: Properties with garden access around the perimeter; most Kenyan residential houses.

Warranty: 3-5 years depending on chemical product.

Read the detailed process in Termite Soil Treatment in Kenya.

Treatment Method 2: Sub-Slab Injection

For buildings where termites are known to be entering through the floor slab (based on inspection findings), the soil beneath the internal floor slab is also treated.

How it works:

• Holes are drilled through the internal floor finish (tiles, screed, or concrete) at regular intervals across the area requiring treatment - typically along internal wall lines, around plumbing entry points, and in rooms where activity has been detected
• Termiticide is injected at pressure through each hole, saturating the sub-slab soil
• All drill holes are sealed with concrete plugs and, where tiled, grout is colour-matched

Best for: Buildings with confirmed internal infestations; buildings on clay soils where termites readily penetrate beneath the slab; post-infestation remediation.

Treatment Method 3: Termite Baiting Systems

For buildings where drilling and trenching are not feasible - heritage buildings, fully tiled properties with no exposed perimeter soil, commercial buildings where disruption must be minimized - Pestraid Kenya deploys a perimeter baiting network.

How it works:

• Monitoring stations are installed in the soil at regular intervals around the building perimeter (and internally where possible)
• Stations are checked quarterly for termite activity
• When termites are found feeding in a station, slow-acting bait cartridges are loaded - workers carry the bait back to the colony, eliminating it through the Transfer Effect
• Empty stations continue to monitor for new colony pressure

Best for: Buildings where physical treatment is impractical; commercial properties; properties that prefer ongoing monitoring over a one-time application.

Cost structure: Initial installation + annual maintenance subscription.

Read more in Termite Baiting Systems vs Soil Treatments.

Treatment Method 4: Direct Wood Treatment

Where termites have established active galleries within specific timber elements of an existing building, direct treatment of the timber provides localized elimination and protective residual action.

Products used:

• Boron-based wood preservatives (e.g., Tim-Bor, Bora-Care): Penetrate deeply into timber, are low-toxicity, and provide long-term protection. Excellent for roof trusses, floor joists, and wall framing.
• Deltamethrin-based contact insecticides: Applied as a surface spray or injection into galleries for rapid knockdown.

Wood treatment is almost always used as a supplementary method alongside soil barrier treatment in Pestraid Kenya's treatment programmes - not as a standalone solution for a structural infestation.

Choosing the Right Treatment for Your Existing Building

Property Type	Recommended Primary Method	Supplementary Method
House with open garden surround	Soil barrier (trenching + injection)	Direct wood treatment if galleries found
House with fully paved perimeter	Drilling + injection through paving	Sub-slab injection at key points
Apartment (ground floor)	Perimeter injection + sub-slab	Wood treatment to any infested elements
Apartment (upper floor)	Individual unit perimeter treatment	-
Commercial building	Baiting system or perimeter injection	Sub-slab injection at entry points
Heritage / protected building	Baiting system	Local wood treatment

For a specialist assessment of your specific property, book a termite inspection in Nairobi or across Kenya.

Step-by-Step: What Happens When Pestraid Kenya Treats an Existing Building

Day 1: Pre-Treatment Inspection

A thorough inspection is carried out first - mapping all termite activity, identifying entry points, assessing construction type, and planning the precise treatment method. Read what this involves in What to Expect During a Professional Termite Treatment.

Day 2-3: Treatment Application

Depending on property size:

• Trenching and soil treatment of external perimeter
• Drilling through paved areas and injection
• Internal sub-slab injection at confirmed entry points
• Direct wood treatment of affected timber elements

Day 3: Sealing and Clean-Up

All drill holes are sealed. The site is cleaned. Pestraid Kenya's technician conducts a final walk-through with the property owner to confirm all work areas.

Day 3: Documentation

A written treatment report, product data sheets, and the treatment warranty certificate are issued. For bank or insurance purposes, these documents are formatted to meet institutional requirements.

Day 60-90: Follow-Up Inspection

A Pestraid Kenya technician revisits to confirm that termite activity has ceased in all treated areas. Any residual activity is addressed under the warranty at no additional cost.

How Much Does Termite Treatment for Existing Buildings Cost?

Property Type	Estimated Cost (KES)
1-2 bedroom flat or maisonette	8,000 - 18,000
3-bedroom house	18,000 - 35,000
4-5 bedroom house	32,000 - 65,000
Large house / complex	60,000 - 120,000+
Commercial building	Quoted per site

For a full cost breakdown and comparison across all treatment types, read our guides on Termite Treatment Cost in Kenya and Termite Control Cost in Nairobi.

Is It Too Late If the Infestation Is Advanced?

No. Even if a building has had a significant termite infestation for several years, professional treatment can eliminate the colony and prevent further damage. The structural timber that has already been consumed cannot be restored by treatment - that requires a carpenter. But the active feeding will stop, the colony will be eliminated, and the barrier will prevent recolonization.

Pestraid Kenya has successfully treated buildings with multi-year infestations across Kenya. The key is to act once the infestation is identified rather than waiting.

For context on what happens when infestations are ignored, read The Dangers of Ignoring Termite Mud Tubes.

Frequently Asked Questions

Do I need to move out during treatment? Typically no. Residents can remain in unaffected rooms. Treated areas should be avoided for 4-6 hours while the termiticide dries. Specific advice is given for each property during the pre-treatment inspection.

Will drilling damage my tiles? Pestraid Kenya uses specialized small-diameter diamond bits to minimize the drill hole size. Holes are plugged with colour-matched grout or concrete. Visible damage to floor finishes is minimal and is repaired as part of the service.

Can the infestation return after treatment? New colonies can establish themselves over time as the chemical barrier depletes. This is why Pestraid Kenya includes annual inspection visits in the warranty period and recommends retreatment before the warranty expires.

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

Protect Your Existing Building Today

An existing building with no termite treatment is a building at risk. Don't wait for visible damage to escalate. Explore all our termite control services or read more expert content on our blog.

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Contact Pestraid Kenya

Pestraid Kenya - Termite Treatment Specialists for Existing Buildings 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