What Happened in Sena: The Reported Facts

According to a Thairath report in October 2026, whose headline described the situation in Sena district, floodwater rose nearly 1 metre inside homes and residents had to keep raising their floors to escape it, until their living space was almost touching the roof. The picture reflects many homes in Ayutthaya's lowlands: single-storey houses, or houses whose upper floor cannot hold everyone. The only option left is to build the floor up with bamboo daybeds, tables, planks, concrete blocks or whatever is to hand, and live on top.

For the provincial picture, according to Manager Online (MGR Online) on 3 October 2026, Phra Nakhon Si Ayutthaya had flooding in 16 districts covering 48,704 households. These numbers reflect the reporting date only. Flood conditions change every day, so follow official announcements from the district, the province and the Department of Disaster Prevention and Mitigation.

What sets the Sena case apart is that the problem is not only the water level. It is the living space that remains, which shrinks every time the floor has to go up again. The gap between the platform and the roof gets narrower, the air gets hotter and staler, and the whole household has to sleep, eat, cook and store belongings in a tiny area, while beneath them lies floodwater mixed with sewage and rubbish. That combination is exactly what many germs thrive on.

Life on a Raised Platform Under the Roof: Why It Is Riskier Than It Looks

Raising the floor to escape the water is a survival skill that lowland communities have practised for generations, and it lets many families stay in their homes. From a hygiene standpoint, though, living this way for days or weeks creates specific risks worth understanding.

• Crowding. Everyone is close together all the time, coughing, sneezing and breathing the same air, so respiratory viruses spread easily.
• Heat and stale air under the roof. A metal or tile roof in the sun all day makes the space beneath it hot, while moisture rises from the floodwater below. Humidity climbs, people sweat heavily, skin stays damp and mould grows well.
• Food and bedding share one surface. Cooking, washing up and sleeping all happen on the same platform, so food scraps, water and many different hands mix together.
• Difficult sanitation. With the bathroom underwater, many households use makeshift toilets or bags. If these are not sealed properly, faecal germs reach the living area immediately.
• The platform supports sit in the water. Daybed legs, concrete blocks and tables used as stilts soak in contaminated water the whole time. When the water drops, they are coated with mud and germs.
• Climbing down into the water. Every trip out of the house to carry supplies or throw away rubbish means direct contact with floodwater.

Example Case: Three Generations on One Platform in Sena

Note: this is an illustrative example describing a typical scenario. It is not a family from the news report.

A single-storey house in Sena is home to three generations: a grandfather in his seventies with diabetes, two working parents and two daughters, one at primary school and one in kindergarten. When the water started to come in, the family pushed the dining table and a bamboo daybed together, set them on concrete blocks and laid mats and thin mattresses on top. The next day the water rose again and another layer of blocks went in. By the time the water was close to a metre, everyone's sitting space was only an arm's length from the roof.

During the day the heat from the roof left everyone drenched in sweat. The younger daughter developed a rash in the creases of her elbows and knees, and the older one came down with a fever and cough after playing with neighbours' children at the relief distribution point. Two days later the little one was coughing too, and Grandfather began to tire easily. The mother cooked on a camping gas stove next to the bedding, washed dishes sparingly with donated drinking water, and hung bags of wet rubbish from a roof beam because there was nowhere else to put them.

When the water eventually fell, the family found thick mud caked under the daybed, dark stains creeping up the table legs, a waterline along the walls, and grey mould spots on the ceiling boards in the corners where condensation had gathered every day. The questions were: what do we take apart first, what can we keep, what must go, and how do we disinfect so that Grandfather and the girls can safely sleep on the floor again?

The Germs in a Flooded Sena Home, Below and Above the Water

The WHO and the CDC explain that floodwater is often contaminated with wastewater, sewage, chemicals and pathogens, and Thailand's Department of Disease Control warns every flood season about the illnesses that follow. For homes where people live on raised platforms, it helps to think in two zones.

Below the water: germs carried by water and mud

E. coli and Salmonella come from sewage overflowing from septic tanks and drains. They settle on floors, furniture legs, the lower walls and the materials used to prop up the platform, and they stay on those surfaces after the water has gone. Picked up on unwashed hands, they can cause diarrhoea, vomiting, stomach pain and fever.

Leptospirosis is a risk for anyone who goes into the water or walks through mud. Rats fleeing the flood often move up to high places, including roof beams, so their urine may contaminate both the water and raised surfaces. The bacteria enter through cuts or skin that has soaked for a long time. Sudden high fever, headache, calf pain or red eyes within about two weeks of contact with floodwater mean a prompt visit to a doctor, with a clear mention of the wading history.

Mould in mud and wet materials. Wood, bamboo, foam and fabric that stay wet will start growing mould within days if they are not dried. The CDC advises cleaning and drying within 24 to 48 hours after floodwater recedes to limit mould.

Above the water: germs that spread in crowded space

Respiratory viruses such as influenza, including H1N1, and RSV spread through coughs, sneezes and hands that touch shared surfaces. In an enclosed space under the roof where everyone breathes the same air, young children and older people are more likely to be infected and to become seriously ill. RSV can make breathing hard for small children, while older people with chronic conditions may develop pneumonia as a complication.

Hand, foot and mouth disease is common in young children and spreads through saliva, nasal mucus, blister fluid and faeces. Shared toys, spoons, cups and sleeping mats are key routes.

Norovirus and rotavirus. When toileting and food preparation happen close together, the chance of gut viruses passing from person to person rises sharply. Norovirus is infectious even in very small amounts.

Mould under the roof and on ceilings. Moisture rising from the floodwater condenses under the roof every day, so ceiling boards, rafters and upper walls that never touched the flood can still grow mould. Many households miss this because they assume the water never reached up there.

People who need extra care

• Older adults, especially those with diabetes, high blood pressure, heart or lung disease.
• Babies and young children, whose immunity is still developing and who dehydrate quickly.
• Pregnant women, who should not wade and should avoid strong chemical fumes.
• Anyone with cuts on the feet or legs who goes into the water often.
• Bedridden or less mobile people who must stay on the raised platform the whole time.

What Follows When the Water Drops in Sena

Health. Taking down the platform and washing the house is when everyone handles the most mud. Without good protection, diarrhoea, rashes, infected cuts and a lingering mould-related cough can follow.

Property. Daybeds, tables and wooden furniture that served as stilts and soaked for a long time will grow mould and rot quickly if they are not washed and dried in time. Mouldy ceiling boards may need replacing, which raises repair costs.

Income and time. Many Sena families farm rice, trade or work in factories. Washing the house several times because it was done in the wrong order, or family members falling ill one after another, means more days off work.

Wellbeing. Weeks in a cramped space under a hot roof are exhausting and stressful. Restoring the home step by step helps the family return to normal life with more confidence.

Why Detergent and a Splash of Bleach Are Not Enough

After the water drops, many households scrub with washing powder and then pour on household bleach. The intention is good, and washing with water and detergent is a first step you must never skip. In a Sena-style home, though, where you have to deal with floors, platform materials and the space under the roof, there are limits to understand.

• Detergent washes away; it is not designed to disinfect. Germs lodged in bamboo grooves, rough concrete blocks or the joints of a daybed may survive washing.
• Bleach fumes in a closed space. In a house with a low roof or a platform still in place, airflow is poor, and bleach fumes can irritate the eyes, nose and airways, a real problem for older people, children and anyone who has just had a cough.
• Dangerous mixing. Bleach must never be mixed with acidic toilet cleaners or ammonia-based products, which can produce dangerous gases. In the chaos after a flood, such mistakes happen easily.
• Corrosion and wear. Strong bleach can rust metal, fade fabric and make rubber and plastic brittle, including pots, pans, buckets and some electrical fittings.
• Quickly inactivated by dirt, with no lasting protection. Once dry, surfaces are open to fresh germs from the hands and feet of everyone coming and going.

The right order is therefore: remove all the mud, let surfaces dry, then disinfect with a product that does not corrode, has no harsh smell and is used at the dilution on the label.

CHEMGENE HLD4H: A Medical-Grade Disinfectant for the Final Step of Recovery

According to the product information, CHEMGENE HLD4H is a medical-grade high-level disinfectant made in England (UK), used in hospitals, clinics, laboratories, schools, offices, airports, homes and elderly-care and childcare settings. The details that matter for a flooded home are:

• Spectrum. According to the product information, it is effective against bacteria, fungi and mould, mycobacteria, Salmonella and viruses including influenza H1N1, RSV, norovirus, hand, foot and mouth disease virus and SARS-CoV-2, matching the germs of both the below-water and above-water zones.
• Speed. The product page states it kills within 1 minute and is 99.85% effective against COVID-19.
• Lasting protection. The product page states residual surface protection of up to 14 days.
• Dilutions. 1:30, 1:50, 1:60, 1:100 and up to 1:200, depending on the job specified on the label.
• Kind to materials. Biodegradable and non-corrosive to stainless steel, aluminium, rubber, plastic and fibreglass.
• Safety. The product page says it is safe for people, pets and medical equipment when used as directed.
• Tests and approvals. Mahidol University, NHS England, ISO 9001:2015, ISO 13485, SGS, Intertek, CE, and EN 13727, EN 14348, EN 13624 and EN 14476.

For homes with older relatives, small children or bedridden family members who will soon sleep on the floor again, choosing a disinfectant without a harsh smell or heavy fumes in rooms with limited airflow is worth taking seriously.

Remember: a disinfectant reduces the risk of infection from surfaces during recovery. It does not prevent flooding and it is not medical treatment. Anyone with fever, laboured breathing, severe diarrhoea, calf pain or an inflamed wound must see a doctor.

A Plan to Dismantle, Wash and Disinfect a Sena Home

A house with a raised platform has one more job than most: the platform has to come down safely first. Work in this order.

Step 1: Safety

• Switch off the power and have an electrician check sockets and wiring that were underwater.
• Wear rubber gloves, boots, a mask and eye protection, and cover cuts with waterproof plasters.
• Keep children, older people and pregnant women out of the house while dismantling and washing.
• Watch for snakes or centipedes that may be hiding under the platform or in piles of belongings.

Step 2: Dismantle and sort

• Bring mattresses, mats, pillows and blankets down. Wash fabrics in hot water with detergent and dry them fully in the sun. Mattresses that got wet with floodwater are usually best discarded.
• Carry the daybed, tables and blocks outside onto a surface you can hose down.
• Throw away food that touched floodwater, wet rubbish and waste bags securely, following local guidance.

Step 3: Wash

• Shovel out all the mud and open every door and window.
• Scrub floors, walls and furniture legs with clean water and detergent, working from top to bottom.
• Brush down the daybed, tables and blocks, especially the parts that sat in water.
• Wipe mould stains from ceiling boards and rafters with a well-wrung cloth dipped in detergent solution.

Step 4: Disinfect with Chemgene HLD4H

• Once surfaces are damp-dry or dry, mix Chemgene at the dilution on the label. As a worked example, 1:50 means roughly 20 ml of concentrate per litre of water.
• Spray or wipe floors, lower walls, furniture legs, the daybed, tables and high-touch points such as door handles, light switches and rails.
• Leave it for the contact time stated on the label.
• For mouldy ceilings and upper walls, wipe the mould off first, then disinfect. Swollen or crumbling boards should be replaced.
• For dishes and food-contact surfaces, follow the label's instructions on rinsing with clean water afterwards.

Step 5: Dry and monitor

• Keep windows open and use fans to drive out moisture for several days.
• Dry wooden daybeds and tables completely before bringing them back inside.
• Re-treat high-touch points regularly and watch for new mould spots.

Read the label every time, keep the product out of children's reach, never mix it with other chemicals and wash your hands after use.

10 Reasons Chemgene HLD4H Suits Sena Homes After the Flood

1. Handles germs below and above the water, from bacteria and Salmonella in the mud to RSV, influenza and hand, foot and mouth virus in crowded rooms, per the product page.
2. Covers fungi and mould, useful after mould stains have been wiped from hard surfaces.
3. No harsh smell, a good fit for low-roofed houses and rooms with limited airflow.
4. Friendly to homes with older people and children: the product page says it is safe for people and pets when used as directed.
5. Will not corrode belongings: safe on stainless steel, aluminium, rubber and plastic, so pots, buckets and metal table legs will not rust from it.
6. Fast: the product page states it kills within 1 minute.
7. Lasting: up to 14 days of surface protection, as stated on the product page, while muddy feet are still coming in.
8. Economical: dilutes up to 1:200 for the jobs the label specifies.
9. Medical grade with test backing: Mahidol University, NHS England, SGS, Intertek and EN standards.
10. Expert help on hand: ask about use at Chemgene HLD4H, call 065-556-6294 or LINE @whd268.

Before and After: From a Platform Under the Roof to a Home You Can Sleep In

Checklist for Families Still Living on Raised Platforms in Sena

• ☐ Separate the food corner from the sleeping and rubbish corners as clearly as possible.
• ☐ Store food and drinking water in lidded containers, up out of children's reach.
• ☐ Wash hands with soap or use alcohol gel before eating, after the toilet and after going into the water.
• ☐ Seal waste bags tightly and get them out of the house quickly.
• ☐ Wipe high-touch spots on the platform, such as edges and rails, with disinfectant diluted per the label.
• ☐ Keep anyone with fever or cough apart as far as possible, and have them wear a mask.
• ☐ Ventilate the roof space by opening vents or upper windows.
• ☐ Wear boots every time you step into the water and wash your legs right after.
• ☐ Watch for high fever, calf pain, red eyes, diarrhoea or breathlessness, and see a doctor promptly.
• ☐ Plan the dismantle, wash and disinfect steps in advance so you can start as soon as the water drops.
• ☐ If the house is dry but still smells musty, consider WHD's ozone disinfection service as an extra step.

Frequently Asked Questions

Can we keep the bamboo daybed and wooden table we used as stilts?
If they are still sound, not rotting and without deep mould, scrub them with water and detergent, dry them fully in the sun and disinfect per the label before reuse. If the wood is soft, smells strongly or is covered in mould, consider discarding it.

The ceiling never got wet. Why is it mouldy?
Moisture from the floodwater below condenses under the roof every day, and constant humidity lets mould grow even where the water never reached. Wipe the stains off, dry the area and disinfect. Replace boards that are swollen or crumbling.

Can we use Chemgene while we are still living on the platform?
Yes, for wiping high-touch points, diluted per the label. In a confined space, wipe rather than mist, keep children away while you do it and store the bottle out of reach.

Grandfather has lung disease. We are worried about fumes.
According to the product information, Chemgene is safe for people when used as directed. Still, keep older relatives out of the room during cleaning and disinfection, open the windows and let them return once surfaces are dry.

How strong should the mix be?
The label lists rates from 1:30 to 1:200 by type of job. Follow the label, without mixing stronger or weaker than specified. If unsure, call 065-556-6294.

Will disinfecting remove the leptospirosis risk?
Disinfectant reduces germs on surfaces that have been washed. Preventing leptospirosis still depends on boots, covering wounds, avoiding long soaks, removing rat shelter and seeing a doctor promptly if fever and calf pain follow wading.

How often should we re-disinfect?
The product page states up to 14 days of surface protection, but while mud is still being tracked in, clean and disinfect the entrance floor and high-touch points again whenever they get dirty.

Make Your Sena Home a Place Everyone Can Sleep Soundly Again

Dismantle, wash, dry, then finish with a medical-grade disinfectant that has no harsh smell and will not corrode your belongings. Order or ask for advice today.

See Details and Order Chemgene HLD4H

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

Related Links and References

• Chemgene disinfectant range
• Professional disinfection service by World Health Disinfection
• Product certificates
• Thairath (Oct 2026): report on flooding in Sena district, water nearly 1 m and floors raised to escape it
• MGR Online (3 Oct 2026): Flood situation in Phra Nakhon Si Ayutthaya
• World Health Organization: WHO fact sheets
• CDC: Floods and your health
• Thailand Department of Disease Control: ddc.moph.go.th