A typical scenario (an illustrative example, not a real person)

Nid lives in a small single-storey concrete house in Sena District with five people: her parents in their seventies, her husband and her primary-school daughter. When water started coming in, the family pushed tables together, stacked wooden pallets and concrete blocks into a platform and laid the mattress on top. The next day the water rose again and they needed more bricks. In the end the platform was so high that sitting up, their heads almost brushed the ceiling.

A single-storey house has no upstairs to escape to. The bedroom, kitchen and bathroom all went under at once. The fridge was lifted onto a table, and the rice cooker and camping gas stove sat next to the bedding. By day the air under the roof was stifling; by night moisture rising from the water below left the blankets damp. Nid's mother, who has asthma, began using her inhaler more often. Her daughter's nose would not stop running. And Nid noticed small black spots appearing on the ceiling above the mattress, even though the ceiling had never touched the water.

What this family went through is what many Sena households are facing. The whole house became one big damp box, not just the part under water. When the flood leaves, recovery has to cover everything from floor to ceiling, and it has to begin with clearing out, washing and drying before anyone talks about ozone.

Where Sena Flooded, and the Wider Ayutthaya Picture in 2026

The information below comes from news reports in early October 2026. Figures change every day, so please check notices from the district, the province and the Department of Disaster Prevention and Mitigation (DDPM) as well.

• Sena District: Thairath (Oct 2026) reported that Sena was still hit hard, with water inside homes nearly 1 m deep and residents raising their floors until they were almost at the roof.
• Ayutthaya Province: flooding in all 16 districts, affecting 48,704 households (Manager Online, 3 Oct 2026). The reports did not give a separate household figure for Sena, so this article uses only the province-level number.
• National picture: DDPM reported on 2 Oct 2026 that 31 provinces plus Bangkok were flooded, affecting 1,245,581 households and 3,535,206 people, caused by heavy to very heavy rain and northern runoff.

"Nearly 1 metre inside the house" may not sound as deep as some places, but in a single-storey home it means the bed, the sofa, the lower wardrobe, the power sockets, the kitchen cabinets and almost every appliance were under water. And when the water stays for days, forcing families to raise the floor again and again, damp builds up through the whole house, not only below the waterline. That is what makes recovery in Sena different from places where water came and went quickly.

How Living on Raised Platforms in Sena Affects Germs and Mold

1. The roof space turns into a steam room. Standing water inside the house evaporates constantly. The moisture rises and collects under a roof heated by the sun during the day, then condenses into droplets as the night cools. Ceilings, roof frames and upper walls that never touched floodwater become damp and can grow mold, even though they look untouched.

2. People live close together in a tiny space. When a whole family eats, sleeps and does everything on one platform, respiratory viruses pass easily from person to person. Clean water for handwashing is limited and the toilet cannot be used normally, so the risk of diarrhoeal illness rises too.

3. The materials used to raise the floor become germ sources. Wooden pallets, plywood sheets, sandbags, tables and concrete blocks that sat in water for days soak up dirty water. After the flood they are often left inside because nobody has the energy to move them yet, and they become ideal breeding grounds for mold and odour.

4. Everything is packed together. Clothes, mattresses, dry food, cookware and medicines are piled into a few square metres. In high humidity, stacked fabric molds quickly and the musty smell transfers to every item.

5. The water stays a long time. When a house sits in water for days and the floor has to be raised again, concrete walls wick water up above the flood line and take weeks to dry completely.

So recovery in Sena has to consider the whole house, from the flooded floor to the ceiling and roof that may never have been wet but absorbed humidity every single day.

Every Germ the Sena Flood Brings: Know Them Before You Start Cleaning

Bacteria: E. coli, Salmonella and leptospirosis

Floodwater moving through a community passes septic tanks, drains, markets and animal pens, carrying bacteria from human and animal waste into homes. E. coli indicates faecal contamination and causes diarrhoea, stomach cramps, nausea and vomiting. Salmonella causes food poisoning with fever and diarrhoea, usually through food or utensils that touched floodwater. In a house where cooking happens on the same raised platform as the bed, keeping clean and dirty areas apart is hard, so the risk is higher than usual.

Leptospira causes leptospirosis, or "rat urine disease". It is found in the urine of rats that escape the water by climbing onto roofs, above ceilings and onto the very platforms families sleep on. It enters through cuts, scratches or skin softened by long soaking. Sena residents who wade inside to fetch things, carry bricks to raise the floor or walk out to collect relief supplies can be exposed. The key signs are sudden high fever, headache, severe calf pain and red eyes. If they appear within one to two weeks of wading, go to a hospital or the local health-promoting hospital quickly and tell the doctor you have been in floodwater.

Viruses: norovirus, rotavirus, RSV and influenza

Norovirus and rotavirus cause diarrhoea and vomiting and spread through hands, spoons, cups and contaminated surfaces, and they survive in the environment fairly well. RSV and influenza spread through droplets from coughs and sneezes in small, stuffy spaces, which describes life on a raised platform under the roof almost exactly. Young children with RSV may breathe fast and hard; older people with flu can become seriously ill and develop pneumonia. If a child is breathing rapidly or an older person has a high fever with breathlessness, see a doctor straight away.

Mold: from floor to ceiling

The WHO and the US CDC generally advise drying wet materials within 24 to 48 hours to limit mold growth. For Sena homes that sat in water for days, that window closed long ago. Mold can be in the lower parts of concrete walls, door frames, particle-board cabinets, mattresses and fabric sofas, and the area to watch most closely is the gypsum ceiling, which absorbed rising vapour throughout the flood. Spores make allergies and asthma flare and cause coughing, a blocked nose and itchy eyes in healthy people too.

Musty and sewage odours

The smell left in Sena homes is a blend of mud, sewage and volatile compounds released by mold and bacteria. It settles into curtains, mattresses, pillows, clothes stacked on the platform, and the concrete and wood themselves. As long as moisture and microbes remain, the smell will not leave on its own.

Who is most at risk: young children, older people, pregnant women, people with asthma, allergies, lung disease, diabetes, kidney or heart disease, and anyone with weak immunity. They should be the last to move back in, once the house has been washed, dried and disinfected.

The Toll on Sena Families When the Whole House Becomes Damp

Health: coughs, congestion and asthma attacks from sleeping under a damp ceiling; diarrhoea from cooking in a contaminated space; rashes and athlete's foot from wading inside every day; and exhaustion from sleepless nights in hot, sticky air.

Money: a single-storey home has nowhere high to move things, so much is damaged at once: furniture, appliances, mattresses and clothing. If mold is not dealt with properly, things that could have been saved are lost too, and moldy ceiling panels may need replacing entirely.

Time: dismantling platforms, hauling out bricks and pallets, shovelling mud, washing and drying belongings takes days. If steps are skipped and the smell or mold returns, the work has to be repeated.

Livelihood: many Sena shophouses are both home and business, whether a food stall, repair shop or general store. When the doors reopen, a musty smell and mold stains are the first things customers notice.

Common Mistakes When Restoring a Single-Storey Home After a Flood

• Washing the floor and forgetting the ceiling: in a home where the floor was raised almost to the roof, the ceiling is usually damp and starting to mold even without direct flooding. Leave it and spores keep dropping down.
• Leaving the pallets and plywood used as platforms indoors: they are saturated with dirty water. Take them outside as soon as the water drops, and discard swollen plywood.
• Using strong bleach in a closed room: it irritates eyes, nose and lungs, especially for asthmatics, and does not penetrate concrete or fabric well. Never mix it with ammonia or acid toilet cleaners.
• Sealing the house and switching on the air conditioner: a unit that was flooded or collected moisture can spread smell and spores everywhere. Have it checked and cleaned first.
• Spraying perfume to cover the smell: it only works briefly and can trigger symptoms in people sensitive to fragrance.
• Painting over damp walls: moisture in the concrete pushes the paint into blisters and mold returns as new spots.

What all of these miss is dealing with germs and odour in the air, in the ceiling void and in corners no cloth reaches. That is the role ozone plays once the house is clean and dry.

WHD Ozone Disinfection in Sena: How It Works and Which Homes It Suits

World Health Disinfection (WHD) provides residential and building ozone disinfection for homes, condos, offices, schools and commercial buildings. Our office is in Bang Khae, Bangkok 10160. We do not have a branch in Sena District. The team can plan trips to serve Ayutthaya by appointment, with travel, dates and coverage confirmed on 065-556-6294 or LINE @whd268, and we do not promise same-day arrival.

How ozone works: ozone (O3) is a strong oxidiser. Spread through a closed room, it breaks down the cell structures of bacteria, viruses and mold and destroys odour molecules, then reverts to oxygen (O2) with no chemical residue. According to the test results the company has certified with the Department of Medical Sciences and Intertek (UK), it eliminates viruses, bacteria and mold by 99.99%. Because it is a gas, ozone rises into ceiling areas and the upper corners of a room, which suits Sena homes where humidity collected high up.

The process:

1. Consultation and photos: photograph every room, including ceilings, wall corners and visible mold, and send them on LINE @whd268 so the team can estimate the zones.
2. Readiness check: platforms dismantled, mud and damaged items removed, floors and walls washed, and the house reasonably dry. If it is not ready, the team will advise waiting.
3. Preparation: people, pets and plants leave the house or treatment zones entirely. Doors and windows are closed; cupboards and drawers opened.
4. Ozone release: generators are set up and the target concentration reached.
5. Contact time: the sealed room is left to work; a typical cycle is about 30 minutes per zone.
6. Rest and ventilation: ozone reverts to oxygen and the house is aired before anyone returns.

Safety first: ozone treatment is done only in an empty, closed space. No people, pets or plants may be inside during treatment, and re-entry happens only after the rest and ventilation period the team confirms. Ozone is a step after mud removal, washing and drying; it does not replace cleaning or medical care. Anyone who feels ill should see a doctor.

10 Reasons Sena Homes Should Consider Ozone After the Water Recedes

1. It reaches ceilings and upper corners: where damp from the raised-floor weeks collected and where hands struggle to clean.
2. It treats the air of a long-stuffy house: helping reduce spores and germs floating in closed rooms.
3. Suitable for homes with asthma patients: no harsh chemical smell once ventilation is complete. See the ozone service.
4. No residue on cookware or bedding: ozone reverts to oxygen. Read more on ozone and chemical residue.
5. It breaks odour down at the source: destroying odour molecules instead of masking them.
6. Often a whole house in one day: single-storey homes split into zones easily, at about 30 minutes per zone.
7. Helps shophouses reopen with confidence: reducing the smell customers notice at the front door.
8. Documented test results: 99.99% according to the company's certified tests. See the certificates.
9. Assessment from photos before travel: no waiting for repeated site visits.
10. Better value with the promotion: jobs of 15,000 baht or more receive a free medical-grade disinfectant spray. Ask about it.

Example Case: A Two-Unit Shophouse That Is Both Home and Motorbike Repair Shop in Sena

(An illustrative example to explain the process, not a real customer review.)

Ek runs a motorbike repair shop on the ground floor of a shophouse, with his family living behind the shop. When nearly a metre of water came in, he moved some spare parts up to the mezzanine, but the back room had to have its bed raised on plastic crates and concrete blocks until it almost touched the ceiling. When the water left, what remained was engine oil mixed with mud on the shop floor, a musty smell from the back bedroom and dark rings on the ceiling panels.

The team advised starting by carrying the crates and blocks outside to wash, discarding the soaked mattress, having an electrician check the wiring before switching anything on, scraping out the mud and washing away the oil with detergent, and removing ceiling panels that had sagged or molded. The house was then opened up for several days until the walls were dry. Once photos confirmed it was ready, the team booked a visit and divided the property into shopfront, bedroom and kitchen zones. The family spent a day with relatives. After the rest and ventilation period, Ek found the musty smell in the back room had dropped markedly. He fitted new ceiling panels where the old ones had been removed and reopened the shop.

The lesson: ozone does not make a sagging ceiling panel or a ruined mattress usable again. Permanently damaged things must be removed or thrown away. But once cleaning is done in the right order, ozone helps deal with the germs and odours left in the air and in the corners of the house.

Sena Flood Recovery Checklist, Step by Step

While you are still living on the platform

• Open any high vents or windows you can to reduce heat and humidity under the roof.
• Keep the cooking corner away from the bed and store food in sealed containers.
• Wash hands with soap or use alcohol gel before eating and after using the toilet.
• Wear boots in the water, cover wounds and wash feet after every trip down.
• Watch for fever, calf pain, diarrhoea or breathlessness and see a doctor promptly.

When the water leaves the house

• Turn off the mains and have an electrician check sockets, wiring and flooded appliances.
• Take pallets, bricks, crates and other platform materials outside to wash or discard.
• Remove all mud and wash floors and walls with clean water and detergent.
• Inspect the ceiling and remove panels that sag, swell or show clear mold.
• Discard food, medicines and soaked mattresses; wash salvageable fabrics in hot water and dry them in strong sun.
• Air the house and use fans or a dehumidifier until the walls are dry.

Before and after ozone day

• Send photos for assessment and confirm the travel date.
• On the day, move people, pets and plants out and keep documents and valuables with you.
• Return only after the rest and ventilation period the team gives you.
• Air the house daily and watch for new mold; clean it at once and find the moisture source.

FAQ: Ozone Disinfection After the Sena Flood

Q: The ceiling never got wet. Does it need attention?
A: It should be checked. When floors were raised almost to the roof, moisture from the water below rose and collected on the ceiling the whole time. Panels with clear mold or sagging should be replaced; sound panels can benefit from ozone once the house is dry.

Q: Is WHD based in Sena?
A: No. The company is in Bang Khae, Bangkok, and the team travels by appointment. Call 065-556-6294 or message LINE @whd268 to confirm travel and timing.

Q: Someone in the house has asthma. Is ozone OK?
A: Yes, provided they leave the house during treatment and return only after rest and ventilation are complete. If their asthma is flaring, they should see a doctor first; ozone is not a medical treatment.

Q: Can we do ozone first and wash later?
A: Not recommended. The correct order is remove mud, wash, dry, then treat. Leftover mud and grime stop ozone working evenly.

Q: How long does it take?
A: About 30 minutes per zone, plus preparation and the rest and ventilation period. Most single-storey homes split into zones easily, and the team estimates from photos.

Q: Will the smell come back?
A: If a moisture source remains, such as walls that are not yet dry or moldy items kept indoors, it can. Keep controlling humidity and ventilating after treatment.

Make Your Sena Home a Place to Breathe Freely Again

Send photos of your home to the WHD team for an assessment first, then decide.

See the Ozone Disinfection Service

Phone 065-556-6294 · LINE @whd268 · Email worldhealthdisinfection@gmail.com

Related services

• Residential and building ozone disinfection
• Ozone cleaning service
• Certificates
• Contact us

References

• Thairath (Oct 2026), Sena District flood report: water nearly 1 m inside homes
• Manager Online (3 Oct 2026), Ayutthaya 16 districts, 48,704 households: mgronline.com
• Bangkok Biz News, DDPM flood report (2 Oct 2026): bangkokbiznews.com
• Thai PBS flood coverage: thaipbs.or.th
• WHO fact sheets: who.int
• US CDC, flood cleanup guidance: cdc.gov/floods