A typical scenario (an illustrative example of a common problem, not a real person's story or words)

A small motorbike and the puddles you cannot avoid on Chao Khun Thahan Road

Fah is in her first year at a company job and rents a second-floor room in an apartment block in a soi off Chao Khun Thahan Road. Every morning she rides her motorbike out of the soi, turns onto Chao Khun Thahan Road and heads to work. In late September 2026 the rain barely stopped. The road she uses every day turned into a chain of puddles. In some places the water just covered the tyres; in others she had to lift her feet onto the bike. Pickups coming the other way threw muddy water over her. She got home in soaked canvas shoes, trousers wet to the knee and the smell of drain water on her skin.

At the apartment, the ground floor had become a small lake. Water from the soi reached the entrance lobby, the motorbike parking and the laundry room with its six coin-operated machines. The coin water-vending machine in front of the building stood in water all day. Ground-floor tenants lifted their belongings onto their beds, and everyone had to cross the flooded lobby to reach the stairs. Some took off their shoes and walked barefoot so their only pair would not get any wetter.

Three days after the water drained, the owner hired workers to hose down the lobby and parking area. Everything looked normal again. But within a week, Fah's neighbour had bad diarrhoea, followed by two or three other tenants on the same floor who used the shared bathroom at the end of the corridor. Fah herself developed itchy, peeling skin between her toes. Her room, with windows shut and air conditioning running throughout the rain, began to smell musty from the wardrobe, and small black spots appeared on the curtain where it touched the wall.

Fah never waded waist-deep. Her building was not flooded to the roof. But living where dozens of people share space, after everyone has walked in from flooded streets, is enough to carry germs from Chao Khun Thahan Road up to the shared bathroom, the stair rail and her own door handle. This article explains how flooding on Chao Khun Thahan Road unfolded according to news reports, which germs dorms and apartment blocks should watch for, and where the disinfection spraying service from World Health Disinfection (WHD) fits in.

Flood points on Chao Khun Thahan Road and around Lat Krabang

According to news reports, between 24 and 27 September 2026 Bangkok received about 300 mm of rain in roughly 48 hours. On 26 September 2026 the Bangkok Metropolitan Administration declared all 50 districts a disaster zone, and the Department of Disaster Prevention and Mitigation reported on 2 October 2026 that around 329,000 Bangkok households had been affected.

For Chao Khun Thahan Road, a Thai PBS report on 29 September 2026 at 13:19 stated that the road had standing water at several points, at about 5 to 20 cm (water on the road surface at the time of the report). "Several points" means people using this road did not meet water in just one place. They passed through puddle after puddle along the route, each collecting rain, drain overflow and roadside rubbish.

The same report listed other flood points in Lat Krabang that people around Chao Khun Thahan Road regularly use:

• Chao Khun Thahan Road: standing water at several points, about 5 to 20 cm.
• Luang Phaeng Road at Lotus Lat Krabang: about 20 cm.
• Lat Krabang Road Soi 30/1: about 10 cm.
• Lat Krabang Road between Khlong Thap Yao and Soi Lat Krabang 14/1: a flood point.
• Lat Krabang Road between Khlong Bua Kra and Kingkaew Junction: a flood point.
• Romklao Road: flooded along several stretches.

For residents who mainly ride motorbikes or walk, crossing several puddles twice a day for several days means repeated contact with the water. Wet shoes, socks, trouser hems and tyres carry mud and contamination into the building every time they come home, even if the building itself was never deeply flooded.

Sources: Thai PBS (29 September 2026) and other reports listed at the end. Depths are as reported at that time; individual sois and buildings may differ.

The germs that follow floods and spread easily in Chao Khun Thahan dorms and apartments

Chao Khun Thahan Road is an area where many students and young workers rent dorm rooms, apartments and rooms, with street food stalls, coin laundries, water-vending machines and convenience stores along the sois. What makes this kind of area different is that many people share common facilities: entrance doors, lift buttons, stair rails, shared bathrooms and washing machines. Germs after a flood therefore travel differently than in a detached house.

Leptospirosis: a top risk for motorbike riders and anyone wading

Leptospira bacteria live in rat urine. When water pools along roads lined with bins and food stalls, the bacteria end up in the water and mud. Wading repeatedly for days, especially with scratches on the feet or skin softened by long soaking, makes infection easier. Symptoms usually appear from a few days to around two weeks after exposure: sudden high fever, headache, severe muscle pain especially in the calves and thighs, red eyes, and in some cases yellowing skin or reduced urination. The Department of Disease Control advises anyone with these symptoms after wading to see a doctor quickly and mention the exposure, because early treatment greatly reduces severity. Inside buildings, lobbies, parking areas and stairs used by people with wet feet may still carry contaminated mud residue.

Norovirus and rotavirus: the enemies of shared bathrooms

Dorms with shared or end-of-corridor bathrooms are places where diarrhoea viruses spread fast. Norovirus needs only a tiny dose to make someone ill, and it lingers on taps, flush buttons, door handles and light switches. When one tenant has diarrhoea or vomits, the next person to use the bathroom may pick it up. After a flood, when water and drainage systems may be disrupted, the risk is higher still. Rotavirus spreads the same way and is especially common in young children, relevant for apartment blocks where families also live.

E. coli and Salmonella: from drain water to street food

Standing water on roads often mixes with sewage carrying faecal bacteria such as E. coli. Salmonella, a cause of food poisoning, is found in wastewater and animal contamination. People in dorm areas rely heavily on street food and made-to-order stalls. If a flooded stall reopens before its food-prep area is properly disinfected, or tenants put food boxes on a shared table that was splashed with mud, germs can find a way in. Another concern is the coin water-vending machine and coin washing machines on the ground floor, where everyone presses buttons and inserts coins by hand.

Mould in small rooms, and fungal skin infections

In a small room with the windows shut and the air conditioning running, moisture from wet clothes, wet shoes and rain-damp walls has nowhere to go. Mould grows easily on curtains, window frames, the back of wardrobes and inside shoes. The CDC and health agencies advise drying out within 24 to 48 hours after flooding to limit mould. People whose feet stay wet for long periods are also at risk of fungal skin infection between the toes, often called athlete's foot, which should be treated properly; don't share shoes or foot towels.

RSV and hand, foot and mouth disease where families live

Although most tenants here are students and workers, many buildings also house families with small children. During long rainy spells, children spend more time indoors and play in lobbies and corridors. RSV, which causes respiratory infections, and hand, foot and mouth virus, which spreads via surfaces children touch, are things building owners should consider too.

Musty smells in the building

The mustiness hanging in the lobby, laundry room and fire stairs comes from trapped moisture, bacteria and mould that are still growing. It is the first thing tenants notice, and a reason many decide not to renew their lease.

The impact on tenants, dorm owners and shops along Chao Khun Thahan Road

Tenants' health. Most dorm residents live alone, away from family. When they fall ill with severe diarrhoea or a fever after wading, there is often nobody to look after them. Some wait until they feel much worse before seeing a doctor, and with a disease like leptospirosis, delay can make things more serious.

Money, study and work. For students, falling ill before exams means missed classes and lost study time. For workers, it means sick days and lost income. For dorm owners, rooms left empty when tenants move out after a flood mean lost income every month.

Time and workload. Building managers face complaints from dozens of rooms at once about smells, bathrooms, washing machines and dirty corridors. Washing again and again takes labour and time.

Reputation. Tenants now search for rooms through online groups and reviews. A photo of mould on a wall or a post about a whole floor getting diarrhoea can hurt occupancy for much longer than expected.

Family worry. Parents who sent their children to study or work in Bangkok see flood news and call every day. The hardest question to answer is, "Is your place safe now?"

Why hosing the lobby and running the air conditioning is not enough

High-pressure water only. Hosing pushes mud off the floor well, but it does not disinfect. It can also splash contaminated droplets onto lower walls, table legs and mailboxes. Without washing with detergent and then disinfecting, contamination remains.

Cleaning only the ground floor. Many buildings focus on the lobby and parking area where water actually came in, forgetting that every tenant walked upstairs with wet feet, held the rail, pressed the lift button and opened the shared bathroom door. Germs spread through the whole building.

Air conditioning with windows shut. Air conditioning removes some humidity, but if wet clothes and shoes stay in the room and the filter is dirty, moisture and smell keep circulating in a closed space.

Air freshener in the lobby. Fragrance masks mustiness for a few hours; the source remains.

Every tenant for themselves. When each person cleans their own way, some rooms are cleaned well and some not at all, and common areas end up as nobody's full responsibility.

Cleaning by yourself is still the essential first step: remove mud, wash and dry first, always. But a building shared by many people needs disinfection done all at once, across every floor's common areas, by a team that knows how to use the disinfectant and equipment correctly.

WHD post-flood disinfection on Chao Khun Thahan Road: disinfectant, equipment and steps

According to World Health Disinfection's service information, the disinfection spraying service is carried out by trained technicians who spray and/or ULV-fog (Ultra Low Volume), turning the disinfectant into a fine mist that spreads along lobbies, corridors, stairs and rooms full of corners. This suits multi-storey buildings with large common areas and shared touch points everywhere.

The disinfectant is CHEMGENE HLD4H, a medical-grade disinfectant from the UK that, according to the service information, contains Benzalkonium Chloride and Didecyldimethylammonium Chloride. The service page lists effect against viruses, bacteria and fungi such as COVID-19, RSV, H1N1, H5N1 and hand, foot and mouth virus, with a stated 99.99% efficacy, and shows approvals or references from Thailand's Department of Medical Sciences, Mahidol University, NHS England and EN 14476:2013+A2:2019.

Five steps from the service information, adapted for dorms and apartments

1. Book. Call 065-556-6294 or LINE @whd268 with the building's location on Chao Khun Thahan Road or a nearby soi, number of floors and rooms, and the common areas to treat.
2. Prepare. Remove mud and clean common areas. Notify tenants in advance to bring in shoes, food and personal items left outside rooms, and set times for them to leave the zones being sprayed.
3. Technicians spray zone by zone: parking, lobby, laundry, stairs and shared bathrooms. Nobody, including pets, should be in the zone being treated.
4. Wait about 30 minutes, according to the service information, and re-enter at the time the technicians give on site.
5. Use the space normally. Open doors and windows to ventilate, then tenants return to common areas.

According to the service information, WHD serves hospitals, schools, malls, airports, offices, airlines, banks and residential buildings. A promotion includes a free CHEMGENE spray bottle and WELLGIENIC wet tissues with the service, and a tax invoice is available, useful as an expense record for dorm businesses.

Straight talk: spraying happens only after mud removal and cleaning. It does not replace washing, drying or repairs to water and electrical systems. The disinfectant is a chemical; tenants and pets must leave the treated zone and return when the technicians say so. Anyone ill with fever, calf pain or persistent diarrhoea must see a doctor. Spraying is not treatment.

10 reasons dorms and buildings on Chao Khun Thahan Road should disinfect after the flood

1. The whole building's common areas in one day. Instead of leaving it to each tenant, disinfection spraying by WHD technicians covers lobbies, stairs, laundry and parking together.
2. Targets shared bathrooms, the easiest place in a building for diarrhoea viruses to spread.
3. Fine mist reaches shared touch points: stair rails, lift buttons, mailboxes, handles and switches.
4. A disinfectant described as medical-grade on the service page: CHEMGENE HLD4H from the UK, referencing EN 14476:2013+A2:2019.
5. Covers viruses, bacteria and fungi as listed on the service page, including RSV and hand, foot and mouth virus.
6. Minimal disruption. The service information says to wait about 30 minutes after spraying, and work can go zone by zone, so tenants need not leave for the whole day.
7. Reassures tenants and parents. Owners can state clearly when the building was disinfected.
8. Lighter load for managers, no more repeated washing without knowing if it is complete. Read more on the disinfection service page.
9. Tax invoice available for dorm businesses and juristic persons.
10. Extras to keep using. CHEMGENE spray and WELLGIENIC wet tissues help managers wipe shared touch points daily, subject to promotion terms.

Before and after: an apartment block off Chao Khun Thahan Road

Example case: a four-storey women's dorm in a soi off Chao Khun Thahan Road

Example case (a hypothetical scenario reflecting common problems, not a real customer testimonial)

Auntie Daeng runs a four-storey, forty-room women's dorm in a soi off Chao Khun Thahan Road. Almost all tenants are students and young office workers. The ground floor has a reception lobby, a laundry room, a guest bathroom and motorbike parking. While Chao Khun Thahan Road had standing water at several points, water from the soi flowed into the parking area and lobby for several days, and every tenant had to walk through it to reach her room.

Daeng washed the ground floor as soon as the water went down, but the phone kept ringing. Parents called to ask whether the dorm was safe, having seen Bangkok flood news every day. Third-floor tenants complained of a strange smell in the shared bathroom, and two friends on that floor had diarrhoea. Daeng decided she needed something more systematic than washing floors.

She booked WHD and planned with the technicians to treat one floor at a time in the late morning, when most tenants were out. Tenants at home were told in advance through the LINE group to close their doors, bring in shoes and items outside their rooms, and wait at the coffee shop at the mouth of the soi while their floor was sprayed. The technicians treated the parking area, lobby, laundry room, stairs, every corridor and the shared bathrooms, then told everyone when they could return.

Afterwards, Daeng messaged parents with the date the dorm's common areas were cleaned and disinfected, and advised tenants who had waded and then developed fever or calf pain to see a doctor. She did not promise nobody would get sick. But having a clear process meant fewer anxious questions in the LINE group, and tenants who had talked about leaving decided to stay.

Checklist for building owners and tenants around Chao Khun Thahan Road

For tenants

• After wading, wash your feet with soap and clean water, dry between the toes, and dress any scratch immediately.
• Keep flood-soaked shoes and clothes outside the room or in a bag, and wash them as soon as possible.
• Dry shoes completely before wearing them again; don't share shoes.
• Open windows when the sun is out and clean the air-conditioner filter.
• Wash your hands before every meal, especially after touching stair rails or using a shared bathroom.
• If you have high fever, calf pain, red eyes or severe diarrhoea after wading, see a doctor and mention the floodwater.

For owners, before spraying

• Have an electrician check ground-floor wiring, sockets and any washing machines that were in water before use.
• Shovel mud from parking, lobby and laundry, and wash floors and lower walls with detergent.
• Throw away damaged doormats, cardboard boxes and other absorbent items.
• Dry areas within 24 to 48 hours, following general public-health advice.
• Give tenants advance notice of spraying times and ask them to bring in items left outside.

After spraying

• Re-enter at the time the technicians give, then ventilate.
• Place hand gel in the lobby and outside shared bathrooms, and wipe shared touch points regularly.
• If rooms closed for a long time still smell musty, consider the residential ozone disinfection service as a complement.
• Watch for returning mould, which means trapped moisture must be fixed at the source.

FAQ: post-flood disinfection on Chao Khun Thahan Road

Q: Water did not enter the rooms, only the parking and lobby. Should we spray?
A: Common areas are where everyone walks and touches. If road water reached them, spraying after cleaning helps reduce germs that tenants might carry upstairs on their feet and hands.

Q: Do tenants have to leave for the whole day?
A: No. Spraying can be planned zone by zone; tenants leave the zone being treated and return when the technicians say so. The service information says to wait about 30 minutes.

Q: Can individual rooms be sprayed?
A: Yes, as agreed between owner and tenant. Tenants should clean the room and pack away personal items, food and toothbrushes first.

Q: What is in the disinfectant?
A: CHEMGENE HLD4H contains Benzalkonium Chloride and Didecyldimethylammonium Chloride, according to the service information.

Q: Does spraying mean we won't get leptospirosis?
A: No guarantee can be given. Disinfection reduces contamination on indoor surfaces, but the main leptospirosis risk comes from wading on the road. Wear boots, cover wounds and see a doctor if symptoms appear.

Q: Is a tax invoice available?
A: Yes, according to the service information.

Make your Chao Khun Thahan dorm a place tenants trust again

Mud cleared? Book WHD technicians to disinfect common areas, shared bathrooms and laundry rooms.

Book disinfection on Chao Khun Thahan Road

Call 065-556-6294 · LINE @whd268

Related links

• WHD disinfection spraying service
• CHEMGENE HLD4H medical-grade disinfectant
• Residential and building ozone disinfection

References

• Thai PBS, Bangkok flood points and water levels, 29 September 2026: thaipbs.or.th/news/content/558830
• Posttoday, Bangkok flood situation: posttoday.com/blogs/general-news/749418
• Dailynews, 29 September 2026: dailynews.co.th/news/6232155
• Department of Disease Control, Thailand: ddc.moph.go.th
• CDC Floods: cdc.gov/floods
• WHO Fact sheets: who.int/news-room/fact-sheets