A typical scenario (an illustrative situation drawn from common post-flood experiences, not a review from any specific customer)

An orchard home in Bo Rai: the water left, but the smell stayed

Somporn grows durian and mangosteen on a small plot in Bo Rai district. His family lives in a single-storey wooden house raised only slightly off the ground, with a shed next to it for fertilizer, a sprayer and stacks of fruit crates. After several days of relentless rain, water from the stream running through the orchard rose under the house and then flowed inside, reaching about mid-shin. It was brown and murky, carrying leaves, mud and the sharp smell of compost.

Two days later the water started to drop. Somporn and his son shoveled out the mud, scrubbed the floors and opened every window to let the breeze through. A week later his wife developed a persistent cough at night, his six-year-old granddaughter had an itchy rash on her legs, and the back bedroom next to the shed smelled exactly like laundry that never quite dried. Greenish-grey spots appeared in the corners of an old wooden wardrobe. Air freshener and mosquito coils masked the smell for an hour at most.

This pattern is extremely common in orchard houses and wooden homes across Trat, one of the wettest provinces in Thailand, where humidity stays high for most of the year. Once a house has been flooded, even briefly, the moisture trapped in timber, walls and furniture becomes an ideal breeding ground for microbes. A home that looks clean is not necessarily a home that is safe to breathe in.

The Trat flood situation in 2026 and the national picture

According to the DDPM report of 2 October 2026, flooding affected 31 provinces plus Bangkok, with 1,245,581 households and 3,535,206 people affected nationwide. The main causes were heavy to very heavy rain combined with runoff flowing down from the north. For Trat, in the Eastern region, the same report listed three affected districts, Bo Rai, Khao Saming and Mueang Trat, totaling 1,310 households, with water levels decreasing.

"Water levels decreasing" is good news, but from a hygiene standpoint it marks the most important window of all. When floodwater retreats, much of what it carried stays behind: mud, sewage residue, rotting plant matter and a great deal of moisture. It clings to floors, the lower parts of walls, the space under raised houses, ground-floor ceilings, gaps under cabinets and, most of all, porous materials such as wood, fabric, mattresses and rugs.

Trat's landscape shapes what post-flood problems look like here. Bo Rai and Khao Saming are known for fruit orchards and rubber plantations, including durian, mangosteen, rambutan, salak and rakam palm. Many families live in orchard houses close to irrigation ditches, streams or canals, with sheds for fertilizer, agricultural chemicals and tools right beside the living space. Mueang Trat, by contrast, has old wooden shophouses in the historic quarter near the Trat River, townhouses, housing estates, shops and guesthouses serving travelers heading to Koh Chang and the other eastern islands.

Every kind of germ that floodwater brings into Trat homes

Floodwater is not clean rainwater passing through your house. Before it reaches your living room, it has flowed through drains, septic tanks, cesspits, animal pens, orchard ditches and roads. The World Health Organization (WHO) and the US Centers for Disease Control and Prevention (CDC) give the same advice: treat every surface touched by floodwater as contaminated until it has been properly cleaned and disinfected. These are the main threats to understand.

1) Sewage bacteria such as E. coli

When septic tanks and cesspits flood, their contents mix with the water. Fecal bacteria such as E. coli and Salmonella can remain on floors, lower walls, table legs, kitchen utensils and children's toys. Hands touch them, then mouths, and the result can be diarrhea, stomach cramps, nausea and vomiting. Young children and older adults are especially vulnerable because they become dehydrated quickly.

2) Leptospirosis, the "rat urine disease"

Orchards, rubber plantations and rice fields in rural Trat are home to plenty of rats. During a flood, the urine of infected rats carries Leptospira bacteria into the water and mud. The bacteria enter the body through cuts, scrapes or skin softened by long soaking. Warning signs include sudden high fever, headache, muscle pain, particularly in the calves, and red eyes, usually within one to two weeks after wading. Thailand's Department of Disease Control repeatedly stresses that anyone with these symptoms after wading through floodwater should see a doctor immediately and mention the exposure. Ozone treats spaces; it does not treat people.

3) Viruses that cause diarrhea, such as norovirus and rotavirus

These viruses spread through contaminated food, water and surfaces. They move quickly through crowded homes and temporary shelters. When one person starts vomiting or has watery diarrhea, others often follow within days. Handwashing with soap and frequent cleaning of high-touch surfaces such as door handles, taps, light switches and dining tables are essential.

4) Mold, the great enemy of homes in a rainy province

Trat is humid to begin with. Once building materials have been soaked, mold can start growing within 24 to 48 hours if they are not completely dry, a timeframe that the CDC and public health agencies consistently highlight. Common post-flood molds such as Aspergillus, Penicillium and Cladosporium release tiny spores into the air, which can trigger coughing, sneezing, a blocked nose, breathing difficulty or rashes in people with allergies, asthma or weak immunity. Wooden houses, timber wardrobes, ceilings, gypsum walls, mattresses and curtains are all favorite places for mold to settle.

5) Musty odor and sewage smell

The smell that lingers after a flood is not just unpleasant. It is a sign that organic matter is still decomposing or that microbes are still growing. A damp-laundry smell usually points to mold; a drain or rotten-egg smell usually comes from sewage sediment and anaerobic decay. In Trat's orchard homes, the odor may also mix with compost, plant debris and fallen fruit that rotted in the water, which makes it heavier and more persistent than people expect.

Who is most at risk

Take special care of young children who crawl and put things in their mouths, older adults, pregnant women, people with diabetes, kidney disease or heart disease, cancer patients undergoing chemotherapy, people with asthma or allergies, and farmers who clean up orchards with cuts on their hands and feet. If your household includes anyone in these groups, keep them away from uncleaned areas and plan a complete disinfection before bringing them home.

What Trat families face when germs and moisture are left behind

Health: A lingering cough, allergy flare-ups, itchy rashes, red eyes, diarrhea or an unexplained fever often begin soon after moving back in.

Money: Mold that spreads into wood, wardrobes, beds and sofas can force families to throw away furniture that could have been saved. Tearing out ceilings or walls because the problem was left too long costs many times more than dealing with it early. When orchard income has also been disrupted by the flood, every baht counts.

Time: Farmers in Bo Rai and Khao Saming need to restore their orchards in time for the season. Coming back every week to scrub mold again eats into time that should go to trees and harvests.

Business and reputation: Restaurants, homestays, guesthouses and small hotels in Mueang Trat that serve travelers on their way to the islands depend on online reviews. A few comments about a musty room can hurt income for a whole tourist season.

Family and peace of mind: Sleeping every night in a damp-smelling room makes a house feel unsafe, and the stress of a disaster does not end just because the water has gone.

Why the usual post-flood fixes are not enough

Wiping surfaces with bleach only: Correctly diluted bleach is good at disinfecting hard surfaces, and it is still a step you should take. But it cannot reach the pores of wood, the space behind cabinets, under beds or inside ceilings. Mixed at the wrong strength, or combined with acidic toilet cleaners, it can also release dangerous gas.

Running fans and hoping for the best: Fans help remove some moisture, but in a humid province like Trat, moving air alone rarely dries timber and walls all the way through. It can also blow mold spores around the entire house.

Spraying air freshener or burning incense: This covers the smell; it does not remove it. When the fragrance fades, the musty odor returns, and some fragrances irritate the airways of people who already have allergies.

Painting over mold stains: One of the most common mistakes. Fresh paint makes a wall look clean, but the mold and moisture underneath remain. Before long the paint bubbles and peels, black spots reappear, and you pay twice.

Cleaning only what you can see: Germs and odors hide in places you cannot see, such as air-conditioner vents, under wooden floors, inside wardrobes, behind refrigerators and in curtains. Ordinary wiping never reaches them.

What actually works is following the right order: remove mud and damaged items, wash, disinfect surfaces, dry as thoroughly as possible, and only then use ozone treatment as a supporting step to deal with airborne germs and odors and with corners that cleaning cannot reach.

WHD ozone disinfection for homes and buildings in Trat

World Health Disinfection (WHD) is a disinfection company based in Bang Khae district, Bangkok. It provides residential and building ozone disinfection for houses, condos, hotels, offices, factories, schools and hospitals. WHD does not have a branch in Trat, but homeowners, shop owners and guesthouse operators in the province can contact the team to plan a service visit. Travel, coverage area and possible dates are confirmed by phone at 065-556-6294 or on LINE @whd268. Same-day arrival cannot be guaranteed, as it depends on the job queue and distance.

How ozone works

Ozone (O3) is a form of oxygen with three atoms and a strong oxidizing effect. Released in a closed space, it spreads throughout the room and into corners that cloths and hands cannot reach. It breaks down the cell walls of bacteria, the outer shells of viruses and mold spores, and reacts with odor molecules so they fall apart. When it has done its work, ozone reverts to ordinary oxygen (O2), leaving no chemical residue on surfaces, clothes or furniture. 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%. You can view the certification documents on the website.

The typical ozone process

1. Inquiry and assessment: Discuss house size, number of rooms, how high the water rose and current conditions by phone or LINE, ideally with photos.
2. Preparation: Confirm that mud has been removed, the area cleaned and reasonably dry, doors and windows closed, and every person, pet and plant moved out.
3. Ozone release: The generator is set up and ozone fills the space one zone at a time.
4. Contact time: Ozone is left to work for the set period, typically about 30 minutes per zone, depending on size and condition.
5. Rest and ventilation: The ozone is allowed to break down and the space is aired out before anyone re-enters.
6. Handover and advice: The team explains how to keep humidity under control so mold does not return.

The most important safety rule: ozone treatment is carried out only in an empty, closed space. People, pets and plants must be out of the area during treatment and may re-enter only after the rest and ventilation period the team specifies. Ozone comes after mud removal, washing and drying. It does not replace cleaning, and it does not replace medical care.

You can also read about WHD's ozone cleaning service and other disinfection services on the website.

10 reasons Trat homes should consider ozone after the water recedes

1. It reaches what cloths cannot. Ozone gas drifts under beds, behind wardrobes, into closets and ceiling gaps.
2. It covers several germ groups at once. Bacteria, viruses and mold, with 99.99% effectiveness according to the company's certified test results.
3. It tackles musty and sewage odors at the source rather than masking them like air freshener.
4. No chemical residue. Ozone reverts to oxygen, which suits homes with small children and older adults. See the WHD ozone disinfection service.
5. Well suited to wooden and orchard houses full of joints, grooves and porous surfaces, typical of Bo Rai and Khao Saming.
6. Helps shops and guesthouses in Mueang Trat reopen with confidence and lowers the risk of reviews mentioning musty rooms.
7. Quick turnaround. Typically about 30 minutes per zone plus ventilation, with no need to close the house for days.
8. Reduces airborne mold spores that trigger allergies and asthma.
9. Carried out by an experienced team that seals off the area and sets a clear re-entry time. Ask questions through the ozone service page.
10. Good value compared with repeated repairs. Ozone jobs of 15,000 baht or more also come with a free medical-grade disinfectant spray under the company's promotion.

Before and after ozone: how a Trat home changes

Note: results depend on cleaning, drying and ongoing humidity control. If materials are still wet, mold may come back.

Example case: a café with guest rooms in Mueang Trat

Example case (a simulated scenario to explain the process, not a real customer review)

Nok runs a café on the ground floor of an old wooden shophouse in Mueang Trat. Upstairs she has three small guest rooms for travelers who stay a night before heading to the pier. After days of heavy rain, about twenty centimeters of water sat in the front of the café for a full day, seeping under the counter, around the drinks fridge and into the fabric sofa where customers liked to sit.

When the water went down, Nok closed for three days. She threw out the soaked sofa, washed the floor with detergent, wiped the counter and utensils with disinfectant according to the instructions, and ran fans and a dehumidifier until the floor was dry. The problem was the smell. A musty odor kept rising up the wooden staircase to the guest rooms, and the first returning guest mentioned that the room smelled damp.

She contacted the WHD team on LINE and sent photos of the café and rooms. The team asked how far cleaning and drying had progressed and then scheduled a visit based on the job queue and travel distance. On the day, the café was closed and everyone left the building. The team divided the space into a ground-floor zone and an upstairs guest-room zone, closed doors and windows, treated each zone in turn, then waited for the rest and ventilation period before letting Nok back in to inspect.

What Nok noticed was that the musty smell that used to drift up the stairs had dropped markedly, and the guest rooms smelled neutral again. She felt confident enough to reopen. The team also advised her to keep the dehumidifier running for a while and to check the corner under the wooden stairs that had been wet, because in a province as rainy as Trat, humidity control after treatment is what keeps results lasting.

Trat flood recovery checklist: before and after ozone

Before you start cleaning

• Make sure ground-floor power is off, and have an electrician inspect the system before switching on if sockets or wiring were submerged.
• Wear boots, rubber gloves, a mask and eye protection, and cover every cut before you begin.
• Watch for snakes, centipedes and scorpions that may have sheltered in the house or orchard shed.
• Photograph the damage before moving anything so you have evidence for relief applications.
• Separate flood-soaked agricultural chemicals and fertilizer from living areas and handle them as the label directs.

During cleaning

• Remove all mud, then wash floors, walls and furniture with clean water and detergent.
• Discard absorbent items that cannot be dried, such as mattresses, pillows, rugs and any food that touched floodwater.
• Disinfect hard surfaces with a suitable product according to its label, and never mix cleaning products.
• Ventilate and use fans and dehumidifiers to dry everything as quickly as possible, especially in the first 24 to 48 hours.
• Wash kitchenware in hot water or disinfectant, and do not drink well or tap water until it is confirmed safe.

On ozone day

• Move every person, pet, plant and fish tank out of the area.
• Open cabinets, drawers and interior doors so the ozone spreads everywhere.
• Close external doors and windows as the team instructs.
• Wait for the full rest and ventilation period before going back in.

After ozone

• Keep controlling humidity: open windows when the sun is out and use dehumidifiers in stuffy rooms.
• Check wall corners, under stairs and wooden cabinets that were wet; deal with new mold spots promptly.
• Clean air-conditioner filters or have a technician service units exposed to water or high humidity.
• If anyone develops fever, calf pain, red eyes, severe diarrhea or breathing difficulty, see a doctor immediately and mention the flood exposure.

Frequently asked questions about ozone treatment in Trat

1. Does WHD have a branch in Trat?

No. WHD is based in Bang Khae, Bangkok, but you can contact the team to plan service in Trat province. Travel, coverage and appointment dates are confirmed by phone at 065-556-6294 or LINE @whd268.

2. Does the house need to be dry before ozone treatment?

Remove mud, wash and dry as much as possible first. Ozone is a supporting step after cleaning. If the house is still soaking wet, mold may keep growing after treatment. The team will help you judge whether you are ready.

3. Can we stay inside during treatment?

No. The space must be empty and closed. People, pets and plants must all leave, and may return only after the rest and ventilation period.

4. How long does it take?

Typically about 30 minutes per zone, not counting preparation and ventilation. Larger or multi-storey homes are treated zone by zone.

5. Does ozone prevent leptospirosis?

Ozone reduces germs in the space and the air, but it does not prevent or treat illness in your body. If you waded through floodwater and develop fever or muscle pain, especially in the calves, see a doctor right away.

6. Will there be any chemical smell afterwards?

Ozone reverts to oxygen and leaves no chemical residue. You may notice a faint after-the-rain smell at first, which fades with ventilation. Learn more about ozone and chemical residue reduction.

7. Is there a promotion?

Ozone jobs of 15,000 baht or more receive a free medical-grade disinfectant spray, subject to company conditions. Ask the team for details.

The water is down. Let your Trat home breathe again.

Get advice on post-flood ozone disinfection for homes, shops and guesthouses in Bo Rai, Khao Saming, Mueang Trat and elsewhere in the province. The team will assess your situation and confirm travel.

See WHD Ozone Disinfection

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

Related links and references

• Residential and building ozone disinfection (WHD)
• Ozone disinfection machines (WHD)
• Contact WHD
• Bangkok Biz News: DDPM flood situation report
• Thai PBS: 2026 flood situation
• WHO fact sheets
• CDC: Floods and cleanup