A typical scenario (an illustrative example, not an interview with any resident)

M is an office worker in Bangkok who is paying off a small holiday house in Pak Chong, bought as a retreat for his parents and a place to escape the city on long weekends. In late September he saw the news that Khao Yai runoff had swollen the Lam Takhong and flooded several subdistricts. A neighbour on the same estate told him by phone that water had entered a number of houses, but the roads were still difficult, so he could not drive up.

Almost two weeks later, with the water gone and the roads open, he made the trip. The moment he opened the front door, a wave of damp, muddy air hit him. A straight brown tide line ran across the living-room wall. The laminate floor had swollen and buckled, the fabric sofa was speckled with green and black mold, and the bottom of the wooden shoe cabinet had started to rot. Rooms sealed for days with no airflow had let moisture build up until mold was creeping along almost every wall.

He spent the whole weekend hauling out ruined items, washing floors and walls and opening every window. But when it was time to lock up and head back to Bangkok, he began to worry: the next time he brought his parents up, would the smell and mold be back? Many Pak Chong holiday-home owners face exactly this problem. A house with nobody living in it lets moisture work silently for days before anyone can deal with it.

Where the Flood Hit in Pak Chong, Nakhon Ratchasima

This summary is drawn from Matichon and Naewna reports covering 22 to 28 September 2026. No other figures have been added, and numbers and water levels may change daily.

• Cause: runoff from Khao Yai flowed into the Lam Takhong, which then overflowed into communities.
• Subdistricts affected: Mu Si, Khanong Phra, Pak Chong and Nong Sarai, all in Pak Chong district.
• People affected: more than 1,000 families.
• Depth: up to 1.7 metres in some places.
• River level in Pak Chong subdistrict: 8.35 metres, compared with a bank level of 6.50 metres.

Nationally, Department of Disaster Prevention and Mitigation (DDPM) data at 06.00 on 5 October 2026, reported by Daily News, showed 26 provinces plus Bangkok affected, with 1,270,151 households and 3,519,416 people. The Office of the National Water Resources (ONWR) warned of heavy rain and flash floods in the north and parts of the south from 5 to 7 October 2026, according to Thai PBS.

The gap between an 8.35-metre river level and a 6.50-metre bank shows how far the water rose above its banks. With some spots reaching 1.7 metres, many single-storey homes would have been flooded up to the window sills or higher. This was not water lapping at the front step; it reached bedrooms, kitchens and the electrical systems of a large number of homes.

What the Flood Left Inside Homes in Mu Si, Khanong Phra, Pak Chong and Nong Sarai

Water coming down from Khao Yai starts as a fast flash flood carrying soil, sediment and debris. When it spills from the Lam Takhong into town, it washes over roads, drains, septic tanks, animal farms and rubbish before entering homes. The result:

• Mud on floors and in corners, pushed under cupboards and beds, into tile joints and beneath laminate or timber flooring.
• Walls and materials that wick water, such as partition boards, gypsum ceilings, plywood and wallpaper, soaking up moisture well above the actual flood line.
• Electrics and appliances, including sockets, wiring, fridges, washing machines and low-mounted air conditioners, that may be damaged or still damp.
• Pipes and sanitary fittings, where floodwater can force sewage back up through floor drains and toilets, leaving stains and odour in bathrooms.
• Damp air in closed rooms, in holiday homes nobody lives in, resort rooms temporarily shut, and shops that had to close.

Pak Chong has a wide variety of buildings. The town centre has shophouses, row houses, townhouses and housing estates, while the outskirts have farmhouses, villagers' timber homes, dairy farms, fields and holiday homes, plus the resorts, homestays, cafes and condos that serve visitors to Khao Yai. Each needs a slightly different approach, but the rule is the same: remove the mud, wash thoroughly, dry completely, and only then deal with the germs and odours that remain.

The Germs Floodwater Brings to Nakhon Ratchasima Homes, and Who Should Be Careful

Thailand's Department of Disease Control, the WHO and the CDC agree that floods raise the risk of infectious disease, both from direct contact with water and mud and from damp homes after the water goes down. The main groups are these.

Bacteria

E. coli is a marker of faecal contamination. Where water has passed through septic tanks, sewers or livestock pens, the chance of finding it on household surfaces is high. It can cause diarrhoea, stomach cramps and nausea. Salmonella often comes from animal droppings and contaminated food and causes fever and food poisoning, so kitchens in holiday homes and restaurants that flooded need especially careful cleaning before anyone cooks there again.

Leptospirosis is among the top concerns after any flood. The bacteria live in the urine of rats and some other animals, survive in standing water and mud, and enter through cuts, grazes or the lining of the eyes and mouth, especially after long soaking. Symptoms include sudden high fever, headache, muscle pain (particularly in the calves) and red eyes. Anyone who develops these after wading or cleaning should see a doctor straight away and mention the flood exposure.

Viruses

Norovirus and rotavirus cause vomiting and diarrhoea and pass easily via hands, dishes and contaminated surfaces. RSV and influenza spread by droplets, surge in the rainy season, and travel quickly when people crowd into shelters or relatives' homes. Young children and older adults are particularly vulnerable to respiratory infection.

Mold

Mold can grow within 24 to 48 hours of materials getting wet, which is why the CDC and WHO urge cleaning and drying as fast as possible. A home left untouched for days after the flood, like a holiday house, usually has far more mold than one where people moved straight back in. Airborne spores trigger allergies, asthma, coughing, sneezing and itchy eyes.

Musty and sewage odours

Post-flood smells come from fermenting mud, wastewater backing up from drains, active mold growth and rotting food or plant matter. If you can still smell it, the source is still in the house, even if you cannot see it.

Higher-risk groups

• Older adults, including parents brought up to relax at a Pak Chong holiday home.
• Young children who play on floors and put things in their mouths.
• Pregnant women and people with chronic illness such as diabetes, kidney or lung disease.
• People with allergies or asthma, who react strongly to mold spores.
• Resort staff, shopkeepers and volunteers who spend long hours cleaning contaminated areas.

The Aftermath Pak Chong Residents Face

Health. Many households notice lingering coughs, blocked noses, rashes or diarrhoea after moving back, without connecting them to a house that is still damp and moldy.

Cost. Water more than a metre deep means many mattresses, fabric sofas, rugs and plywood furniture must go. If moisture lingers, mold spreads to items that could have been saved, and the bill keeps growing.

Income and business. Pak Chong depends heavily on tourism. A room that smells musty or shows mold stains disappoints guests and invites bad reviews. Restaurants and cafes also need to be sure their kitchens and seating areas are genuinely clean before reopening.

Time. Holiday-home owners based in Bangkok or other provinces can usually only come up at weekends. Having to return again and again to fight odour and mold costs both time and travel money.

Family. A house meant to be a place of rest becomes a source of worry about everyone's health. Completing every recovery step properly is what turns it back into a real retreat, where parents and children can sleep soundly again.

Why the Usual Fixes Do Not Finish the Job

Shovelling mud, washing and drying are the core of recovery. But the steps many people take afterwards only solve part of the problem.

• Wiping with bleach works on smooth, already clean surfaces, but cannot reach under laminate, inside partition walls or into the air. Mixed with other cleaners, it can also produce harmful fumes.
• Leaving the air conditioner or fans running reduces humidity a little, but if the air conditioner itself was flooded or harbours mold, it simply spreads spores around the house.
• Scented candles or air fresheners mask the smell briefly without removing its source.
• Repainting or re-papering over mold lets it keep growing behind the new finish until it bubbles and lifts.
• Locking the house and coming back later is the worst option of all, because a closed, humid room is exactly what mold loves.

What these methods lack is the ability to reach the air and every corner of a room at once, which is where ozone treatment is strongest.

How WHD Ozone Disinfection Works for Pak Chong Properties

World Health Disinfection (WHD) provides ozone disinfection for homes, condos and buildings, as well as hotels, offices, factories and schools. Ozone (O3) is a strongly oxidising gas. Released into a closed, unoccupied room, it spreads throughout, slipping into corners, under furniture and into fabrics, where it breaks down the cell structures of viruses, bacteria and mold and splits apart odour molecules. It then reverts to oxygen (O2), leaving no chemical residue.

According to test results certified for the company by Thailand's Department of Medical Sciences and Intertek (UK), the system eliminates viruses, bacteria and mold by 99.99%.

Safety rules to follow

• Always clean and dry first. Ozone does not replace mud removal or washing.
• Treat empty rooms only. People, pets and plants must leave, and return only after the rest and ventilation period set by the technician.
• Health is a doctor's job. Anyone with fever, calf pain, diarrhoea or breathing difficulty must see a doctor. Ozone is not a medical treatment.

Process

1. Initial chat and assessment by phone or LINE, with photos, room sizes, how high the water reached and where the odour or mold is.
2. Preparation: close doors and windows, open cupboards and drawers, remove people, pets and plants.
3. Set-up and release: the technician controls ozone output to suit the room size.
4. Contact time: typically about 30 minutes per zone.
5. Rest and ventilation: the room is aired for the recommended time before re-entry.

Arranging service in Pak Chong and elsewhere in Nakhon Ratchasima

WHD is based in Bang Khae, Bangkok 10160, and has no branch in Nakhon Ratchasima. Jobs in Mu Si, Khanong Phra, Pak Chong, Nong Sarai or elsewhere in the province are planned together by phone on 065-556-6294 or LINE @whd268. The team confirms travel, coverage and possible dates when you get in touch, and cannot guarantee same-day arrival. Owners who live elsewhere can choose a date when they or a caretaker can open the property.

Promotion: book an ozone job of 15,000 baht or more and receive a free medical-grade disinfectant spray.

10 Reasons Pak Chong Homes, Resorts and Shops Should Consider Ozone After the Flood

1. It treats the air, not only the surfaces you can wipe.
2. One cycle covers bacteria, viruses and mold. See the ozone service.
3. It removes musty and sewage odours at the source instead of covering them with fragrance.
4. Ideal for holiday homes left shut, where stale, humid air has built up.
5. It helps prepare guest rooms for resorts and homestays planning to reopen.
6. No chemical residue, as ozone turns back into oxygen after the cycle.
7. It reaches fabrics and upholstered furniture that were kept after cleaning.
8. Short cycles, typically about 30 minutes per zone, excluding preparation and airing.
9. Certified results: according to test results certified for the company, it eliminates viruses, bacteria and mold by 99.99%. Read more.
10. Fewer repeat trips for owners who live far away and can only visit at weekends.

Before and After Ozone: A Pak Chong Home Flooded by the Lam Takhong

Note: results depend on the building and remaining moisture. Rotten or deeply moldy materials, such as swollen plywood or sagging ceilings, may need replacing too.

Example Case: A Roadside Shophouse in Pak Chong Subdistrict

Example case (an illustrative scenario explaining the steps, not a review from any customer)

Nid runs a small grocery on the ground floor of a two-storey shophouse and lives upstairs with her elderly mother. When the Lam Takhong overflowed, water entered the shop and she carried what she could upstairs; most of the stock she could not move had to be thrown away.

After the water dropped, the family shovelled mud, washed the floor and shelves, discarded swollen plywood shelving and left the roller shutter open with fans running for days until the floor was dry. But at night, with the shop shut, musty and drain smells drifted upstairs and her mother began coughing more. Nid took her mother to a doctor first, then looked for a way to deal with the building.

She called WHD on 065-556-6294 and sent photos of the shop and upstairs rooms. The team advised cleaning the floor drains and bathroom thoroughly, confirming the walls were dry, and then booking a date the crew could travel. On the day, everyone left the building and the technician treated one floor at a time. After the rest and ventilation period, the odour in the shop and bedroom was clearly lower, and Nid began restocking and reopened, while keeping humidity under control.

Pak Chong Flood Recovery Checklist, Before and After Ozone

Before going in

• Check local announcements that the area is safe and the Lam Takhong has dropped.
• Switch off at the breaker and have an electrician check flooded sockets, wiring and appliances.
• Wear boots, rubber gloves and a mask, and cover any wounds.
• Photograph the damage before cleaning, for aid applications or insurance claims.

Clean and dry

• Remove mud while it is still wet and wash from top to bottom.
• Discard soaked mattresses, rugs, upholstery, plywood and swollen gypsum.
• Throw away food, medicine and cosmetics that touched floodwater.
• Clean drains, bathrooms and water tanks; wash air-conditioner filters or have flooded units checked.
• Ventilate and use fans or dehumidifiers to dry the house as fast as possible.

Around the ozone treatment

• Tell the team the area and problem spots; open cupboards and drawers.
• Keep people, pets and plants out during treatment and the rest period.
• Re-enter only after the ventilation time the technician gives.
• If anyone develops fever, calf pain, red eyes, diarrhoea or breathing difficulty, see a doctor immediately.

FAQ: Ozone After the Pak Chong Flood

1. My holiday home was shut for days after the flood. What first?

Ventilate, cut the power, remove damaged items, shovel out mud, wash and dry. Once materials are dry, consider ozone for the germs and odour left behind.

2. Do I need to be there during treatment?

Someone needs to open the property and go through the steps with the team, but during treatment everyone must leave. Rooms must be empty of people, pets and plants.

3. Can ozone save a moldy mattress?

We do not recommend it. Mattresses soaked by floodwater usually hold mud and germs deep inside and should be discarded. Ozone suits rooms and items that have already been cleaned and dried.

4. How long does it take?

Typically about 30 minutes per zone, excluding preparation and ventilation.

5. Does WHD have a branch in Pak Chong or Korat?

No. WHD is based in Bang Khae, Bangkok. Service in Nakhon Ratchasima is planned by phone on 065-556-6294 or LINE @whd268, with travel confirmed at the time. Same-day arrival is not guaranteed.

6. Can resorts and hotels use the service?

Yes. The service covers homes, condos, hotels, offices, factories and schools. Share the number of rooms and floor area so the team can plan zone by zone.

7. If I feel unwell, is ozone enough?

No. Ozone looks after the building, not illness. If you have fever, muscle pain, diarrhoea or breathing difficulty after flood contact, see a doctor and mention the exposure.

Plan Post-Flood Ozone Disinfection in Pak Chong With WHD

Send photos of your home, guest rooms or shop, with the floor area and subdistrict, whether Mu Si, Khanong Phra, Pak Chong, Nong Sarai or elsewhere in Nakhon Ratchasima, so the team can assess and confirm travel.

See the Ozone Disinfection Service

Call 065-556-6294 | LINE @whd268 | worldhealthdisinfection@gmail.com

Related Services

• Ozone cleaning service
• Removing chemical residue with ozone

References

• Matichon: Khao Yai runoff into the Lam Takhong floods Pak Chong subdistricts
• Naewna: Pak Chong flood situation
• Daily News: DDPM flood data, 06.00 on 5 Oct 2026
• Thai PBS: ONWR heavy rain and flash flood warning, 5 to 7 Oct 2026
• CDC: Floods and cleanup safety
• Department of Disease Control, Thailand

Note: figures and water levels reflect the reporting period given and change daily.