BANGKOK, THAILAND – A tiny hairline crack in a Bangkok condo ceiling turned into a major headache for long-term tenants after earthquake-related repairs were ordered.
The crack and what followed
For expat Bally J., it started with a barely visible crack in the ceiling, caused by a mild earthquake that briefly shook Bangkok the previous year. In November 2025 his landlord announced what seemed inevitable: the cracks had to go.
In practice this meant large areas of ceiling and walls would be cut open, re-plastered and repainted while the unit was still occupied. At the centre of concern was a built-in ceiling air-conditioning unit that could blow construction dust directly into the living space.
Seismic activity and the impact on buildings
Thailand was not located in a classic earthquake zone, but tremors from Myanmar and Laos in 2023 and 2024 had shown tangible effects on Bangkok high-rises. These ranged from slight vibrations to visible cracks in plaster.
In many condo towers, settlement cracks appeared after such tremors. They were often not structurally dangerous but needed sealing to prevent moisture from causing further damage. Not every crack was the same, and that distinction was crucial for tenants.
Cosmetic or structural: assessing cracks
Hairline cracks under two millimetres wide were generally settlement cracks without structural significance. They formed through thermal expansion or light vibrations and did not affect the building’s load-bearing capacity.
Wider cracks over three millimetres, step-shaped patterns along joints, or sticking doors and windows were red flags for structural damage. In such cases simple filler was not enough; the condo’s juristic person should call in a structural engineer, and tenants were advised to consider moving out.
The problem with ceiling cassette units
Wall-mounted air conditioners could be taped off or removed relatively easily before construction. Ceiling cassette units, by contrast, were integrated into a suspended gypsum ceiling – exactly where sawing, grinding and sanding took place during repairs.
The resulting construction dust was extremely fine and penetrated the louvers, evaporator and filters of the unit. Anyone switching the system back on without a thorough cleaning risked blowing that dust into the room for weeks, creating a problem that went far beyond visible dirt.
Construction dust and lungs: the silent risk
Gypsum and cement dust contained fine particles that could reach deep into the lungs. Thailand already struggled seasonally with elevated PM2.5 levels from burning and traffic. If indoor construction dust was added, exposure could climb to many times the WHO guideline.
For people with asthma, allergies or chronic respiratory conditions this was more than a minor nuisance. Residents in Thailand were urged to check whether their international health insurance covered such respiratory problems.
What Thai rental law required
Thailand’s Civil and Commercial Code obliged the landlord to keep a rental unit in habitable condition. Repairs to earthquake-related cracks fell under this responsibility, and costs had to be borne by the owner or their building insurer.
Tenants were required to tolerate necessary repairs and grant access to the landlord. However, this duty had limits: it did not extend to situations where the apartment became effectively uninhabitable because of the work, a key point of contention in many disputes.
Rent reduction: theory versus reality
If an apartment became temporarily uninhabitable due to noise, dust or lack of air conditioning, tenants theoretically had a right to a rent reduction. In extreme cases, immediate termination of the lease was also possible.
In practice, enforcing such rights in Thailand without a lengthy legal battle was difficult. The more pragmatic route was often to reach a written agreement with the landlord in advance, covering schedule, protective measures and who would pay which costs.
How to protect the air conditioner
Before work began, the air-conditioning unit should be disconnected from the power supply and all openings sealed hermetically with construction film and tape. Simple kitchen cling film was not sufficient, and tenants were advised to supervise this step personally before workers started.
After painting and finishing, a professional deep cleaning of the unit was considered essential. Depending on the model, this cost between 1,500 and 3,000 Baht (about 41 to 82 euros), and tenants were urged to secure a written commitment from the landlord to cover this service.
Putting agreements in writing before work starts
Verbal promises from landlords carried little weight if problems arose. Tenants were encouraged to demand a written timetable specifying when work would take place, what protective measures would be implemented and who would pay for final cleaning and air-conditioner servicing.
They were also advised to photograph the condition of the cracks and the air-conditioning unit before construction started. This documentation could later show which damages had existed beforehand and which had been caused by the renovation.
Temporary move-out as the safest option
Once walls were being cut open, a flat effectively became a construction site. The safest course was to negotiate a rent break for the duration of the work and use that money for a hotel or serviced apartment.
A decent room in Bangkok started at around 1,200 Baht (about 33 euros) per night. For three to five days of construction, this was a manageable investment compared with the potential health costs of breathing construction dust for weeks.
Getting through renovation well prepared
Tenants who acted early could avoid most problems. Recommended steps included documenting the current condition with photos, covering furniture with plastic sheeting, ensuring the air conditioner was sealed, and placing a piece of 3M filter fleece as an extra barrier before moving back in.
In a country where outdoor air quality was often challenging, the home needed to remain a safe retreat. With a written plan, clear agreements and some personal initiative, tenants could achieve this even during disruptive renovation works.
The guidance was based on a real discussion in an English-language forum from November 2025. The legal assessments were not legal advice, and in serious disputes tenants were urged to consult a lawyer or the consumer protection agency OCPB.