Asbestos was the default cheap reinforcing and insulation fibre in Kenyan construction for decades — especially from the 1960s through the 1990s — and it hides in predictable places. Roofing and cladding: the corrugated asbestos-cement sheets ('mabati ya zamani') on industrial sheds, schools, older residential blocks and estate houses across the country. Ceilings: asbestos-cement ceiling boards and tiles, often behind later finishes. Pipe lagging and insulation: around boilers, steam pipes and calorifiers in hospitals, institutions and industrial plant — often the most dangerous form, as insulation fibres are loose and airborne on disturbance. Water tanks and gutters: asbestos-cement products again. Floor tiles and adhesives: vinyl asbestos tiles and the bitumen adhesives beneath older floors. And fire doors and flue pipes in older commercial buildings. The rule: any pre-2000 building should carry an asbestos survey before demolition or major renovation touches it — and many post-2000 buildings inherited legacy materials in extensions and plant rooms.

By containment and discipline, because the material itself cannot be made safe — only the exposure can be prevented. The licensed method: survey and assessment first — a management or refurbishment/demolition survey mapping the material, its condition and its removal scope. Isolation and notification — the work zone sealed, personnel briefed, neighbours notified. Enclosure and negative pressure — removal work, particularly of insulation and interior products, runs inside sealed enclosures with HEPA-filtered negative-air units, so no fibre escapes the workspace. Wetting and controlled removal — bonded products like roofing sheets are wetted down, removed whole where possible, and handled gently: the danger multiplies when sheets crack or are broken. Decontamination — workers in rated RPE and protective clothing pass through decontamination units; no one walks fibres out of the zone. Packaging and sealed transport — double-wrapped, labelled, to licensed facilities only. And air monitoring and clearance — the zone is tested before reoccupation. Every step is documented, because the paper trail is what NEMA and the health authorities examine — and what protects the contractor, the client and the next trade.

Only trained, equipped and documented teams should touch asbestos — and on significant scopes, only licensed specialists. The competence markers: survey competence first — the initial survey itself is a specialist discipline, and its quality decides the safety of everything after it; trained removal crews — workers with documented asbestos-specific training, medical surveillance and fit-tested respiratory protection; method statements — site-specific removal plans, enclosures and emergency procedures; equipment — negative-air machines, HEPA filtration, decontamination units and wetting systems, all testable on site; and documentation — waste consignments, disposal certificates, air-monitoring records and the clearance certificate. The verification habit that protects developers: ask for the clearance certificate and the disposal manifests from the last comparable job. Teams that cannot produce them are telling you exactly how your job will run.

Asbestos is the headline, not the whole list. Lead paint — on older steelwork, tanks and timber, toxic on abrasive stripping and burning. Chemical and fuel stores — underground tanks and drums in petrol stations, factories and institutions, requiring emptying, cleaning and certified disposal before demolition touches them. Refrigerants and gases — CFC and HCFC refrigerants in plant and cold rooms must be recovered by licensed handlers before equipment is scrapped. Fluorescent tubes and batteries — mercury-containing tubes and lead-acid batteries route to specialist recycling, never general waste. Medical and laboratory waste in hospitals and research buildings — sharps, pharmaceuticals and biological waste under their own strict rules. Contaminated ground — fuel spills and industrial residues that turn the excavation phase into a remediation project. Each material carries its own handling method, its own licensed route and its own paper trail — and the survey's job is to find them all before the machines arrive, because discovery during demolition converts a line item into a programme.

Pricing follows the material's form and condition more than its quantity. Surveys — the essential first step — run KES 60,000–150,000 for typical commercial and institutional buildings depending on size and access. Bonded products, removed whole — roofing sheets, cladding, tanks in good condition — typically KES 500–1,200 per m² of material area, the band set by access, height and enclosure needs. Loose insulation and lagging — the high-hazard interior work inside enclosures — prices per project, commonly two to four times the bonded-product band, because labour, air management and monitoring dominate. Disposal rides on top: sealed packaging, licensed transport and gate fees at the small number of facilities licensed for hazardous waste, with consignment documentation. The budget insight: asbestos removal before demolition is cheaper than asbestos discovery during demolition — every time. The demolition cost guide prices how hazardous findings move the overall budget when they arrive late.