A Story from the Field: Uncle Prasert's Wooden House by the Canal Mouth

Uncle Prasert is sixty-five and a small-scale fisherman in a canal-side community in Phra Samut Chedi district. His home is a two-storey wooden house raised about one and a half meters off the ground, built in his father's time. The open space under the house holds his nets, crab traps, ice boxes and the engine for his long-tail boat. Upstairs are the bedrooms where he, his wife and their seven-year-old granddaughter sleep. The girl's parents work in the city and send money home.

During the October 2026 floods, heavy rain drained into the canal just as the sea tides were running high. Water rose under the house until it covered half the height of the stilts, and on some nights it spilled over onto the lowest floorboards. It would drop during the day and come back at night, over and over. It took almost two weeks before the water finally stayed down.

When it did, the space under the house was covered in thick, sticky coastal mud mixed with rubbish, shells and dead fish. A rotten, fishy smell drifted up through the gaps between the floorboards all day long. The lower parts of the wooden walls had a clear tide line, and the surface of the wood was turning fuzzy white with green and black spots. The wooden wardrobe in the downstairs room smelled so musty that his wife had to take out every piece of clothing and wash it all again. Their granddaughter started coughing and getting a blocked nose at night. Uncle Prasert himself had a cut on his foot from wading out to save his nets.

"A wooden house breathes," he said. "Leave it alone and it will dry out." But a week later the smell was still there, and in the evenings, when the wind dropped, the odor from under the house became even stronger. His daughter in the city called to ask where a family should even begin with a house like this.

This article is written for families in the fishing and riverside communities of Phra Samut Chedi, Pak Khlong Bang Pla Kot, Laem Fa Pha, Na Kluea and nearby coastal areas who live in raised wooden houses and want to make their homes comfortable and healthy again after the flood. It explains why wooden stilt houses are harder to recover, why the usual methods disappoint, and how disinfection fogging and ozone treatment can be adapted to a house that is full of gaps by design.

Why Wooden Stilt Houses in Fishing Communities Recover More Slowly

• Repeated flooding from high tides. The wood never gets a chance to dry between rounds, so moisture soaks deep into the boards, stilts and beams.
• The underfloor space collects mud. Coastal mud is rich in organic matter. When it sits and ferments under the house, it produces a rotten smell and becomes a breeding ground for germs.
• The floorboards have gaps. Odor and humidity from below float up into the rooms constantly, with nothing to stop them.
• Fishing gear holds a fishy smell. Nets, traps, ice boxes and sacks that sat in floodwater add to the odor and give germs somewhere to live.
• Wood is porous. Mold can root itself into the grain. If you only wipe the surface, it comes back as soon as the humidity rises again.
• Coastal air is humid and salty. The air is damp almost all year, so houses near the sea dry far more slowly than houses inland.

None of this means a wooden house is a lost cause. Traditional stilt houses are actually well designed for airflow once the mud is gone. The challenge is that the very features that make them breathe also make it hard to keep a treatment inside long enough to work, and that is exactly what a good plan has to solve.

The Impact on Health, Livelihood and the House Itself

Family health. Coastal mud and floodwater that has flowed through the community may carry organisms that cause diarrhea and skin infections. Cuts on the feet from wading can become inflamed, and areas with many rats carry a risk of leptospirosis. Mold spores on floors and wooden walls can trigger allergies, coughing and a blocked nose, especially in children and older people. If anyone develops a high fever, muscle pain, or a wound that becomes red and swollen, they should see a doctor. This article is not medical advice.

The fishing livelihood. Nets and gear left sitting in mud will rot and keep a permanent smell if they are not washed and dried. Getting back out on the water even one week sooner makes a real difference to a fishing family's income.

The house. Wooden stilts, beams and floorboards that stay damp for a long time are at risk of rot and termites. If mold is allowed to spread, repairs later will cost many times more than dealing with it now.

Sleep. A musty, fishy smell rising through the floor at night makes it hard to sleep well. For someone who has to wake at four in the morning to go out on the boat, poor sleep is more than an inconvenience.

Why the Usual Methods Fall Short in a Wooden House

• Waiting for the house to dry by itself. In humid coastal air, the lower parts of the house can take a very long time to dry, and mold keeps growing in the meantime.
• Pouring bleach onto wooden floors. It seeps into the gaps, leaves pale blotches on the wood, and the fumes are unpleasant to breathe. It does nothing about the moisture inside the timber.
• Sanding and then oiling or painting over the wood. If the wood is still damp, paint and oil lock the moisture inside, and mold returns beneath the coating.
• Burning incense or citronella to cover the smell. It masks the odor for a while, but the source under the house is still there.
• Cleaning only the inside of the house. The underfloor space is the main source of odor. If mud is still fermenting down there, no amount of cleaning upstairs will stop the smell rising again.

What these approaches have in common is that they treat the symptom in the room rather than the source below it, and none of them reaches into the gaps and grain of the timber where germs and mold actually live.

The Solution: Work from the Ground Up, Then Disinfect and Ozone-Treat with the Vents Sealed

A raised wooden house has to be thought of in two layers: the underfloor space, which is the source of the odor, and the living space above, which absorbs the odor and humidity rising into it. The World Health Disinfection (WHD) team starts with disinfection fogging under the house and across the floorboards, using CHEMGENE HLD4H through ULV equipment that sends an ultra-fine mist into the gaps between boards, around the stilts and under the beams. Then comes ozone treatment in the upstairs rooms after the vents have been temporarily sealed, to help reduce mold spores and break down the odor molecules trapped in wood and fabric.

How the Work Is Done

1. Survey the house and the tide table. We look at the water line on the stilts, the condition of the floorboards and wooden walls, and the space underneath, then plan the work day for a period of low tide and light wind.
2. Advice on removing mud and fishing gear. Shovel out as much of the mud under the house as possible. Rinse nets and traps with clean water and leave them to dry in the sun, separately. Throw away sacks and anything that has rotted.
3. Fog the underfloor space. We mist around the stilts, under the beams and floorboards, and over the ground where mud had been fermenting, to reduce the germs at the source of the smell.
4. Fog the inside of the house. We treat the floorboards, the gaps between them, the lower parts of the walls, wooden cabinets and the bathroom so the mist reaches every corner.
5. Seal the vents temporarily. Plastic sheeting is used to cover wide floor gaps, louvered windows and the ventilation openings above doors, so the ozone stays in the room long enough.
6. Controlled ozone treatment. Rooms are treated one at a time according to their size. During treatment there must be no people, pets or plants in the house. Rubber items and sensitive electronics are moved out or covered.
7. Open up and ventilate. The plastic is removed and every window is opened for the time the team specifies, until there is no ozone smell, and only then does the family go back in.
8. Re-check and aftercare advice. We check the odor and the wood surfaces again, advise on keeping the underfloor space open to the breeze, and point out any stilts that should be inspected by a carpenter.

Ozone safety: No people, pets or plants may be in the house during ozone treatment. Because wooden houses have so many openings, the team seals the vents and lets close neighbors know in advance. The house must be fully ventilated before anyone goes back inside. Rubber items such as boots and hoses should be moved out, because concentrated ozone makes rubber age faster.

How to Deal with the Underfloor Space So the Smell Does Not Return

Always remove the mud first. Disinfection works best once most of the mud has been shoveled out. A thick layer of mud stops the disinfectant from reaching the surfaces underneath. Wear rubber boots, rubber gloves and a mask while you work.

Open the space to the wind. Move anything piled against the stilts. Hang nets and traps on a rail instead of leaving them on the ground. When the breeze can blow straight through under the house, the timber dries much faster.

Level the ground. If the ground under the house has dips where water collects, fill or reshape them so water can drain away. Standing water is both a source of smell and a mosquito breeding site.

Create a separate zone for fishing gear. If possible, store fishy-smelling equipment on the side of the underfloor space farthest from the bedrooms, or under a separate roof, so less of the smell rises into where people sleep.

Check the stilts and beams. Stilts that stood in water for a long time should be inspected by a carpenter for rot and termites, especially at the base where they enter the ground. The safety of the structure matters more than the smell.

Families often ask whether they should cover the ground under the house with concrete or plastic. That is a longer-term decision best made with a builder. In the short term, the priority is simply to get the mud out, let air move freely, and stop water from pooling.

Checklist Before the Team Arrives

• Photograph the water line on the stilts, the wooden walls, the floorboards and any damaged belongings, for relief applications or insurance claims.
• Shovel out as much mud from under the house as you can, and clear away rubbish, shells and dead fish.
• Rinse nets, traps and ice boxes with clean water and leave them to dry in the sun outside the house.
• Remove mattresses, pillows and fabrics that were soaked. Wash anything still usable in hot water and dry it in the sun.
• Have an electrician check low-level wiring and sockets before switching the power back on.
• Move rubber boots, hoses and other rubber items out of the house, and plan to take radios, phones and small appliances elsewhere during treatment.
• Arrange somewhere for family members, small children and pets to stay during ozone treatment and ventilation, such as a relative's house or the community hall.
• Look at the tide table with the team to choose a day when high water is not expected.

Ongoing Care for a Wooden House After the Flood

A coastal wooden house needs more ongoing attention than a concrete one. For the first one to two months, open the windows every sunny day. Walk under the house once a week, and if a high tide leaves new water or mud behind, clear it out quickly. Wipe door handles, stair rails and the dining table regularly with a disinfectant spray, and make sure children sleep on bedding that has been washed and dried completely.

Once the wood is properly dry, which may take several weeks, you can think about sanding the surface and applying a protective wood oil. If new black spots appear or the musty smell returns, contact the team early for a re-assessment. And do not forget the standing water around the house: mosquitoes multiply very quickly in waterside communities after a flood.

Many families find it useful to keep a simple note on the wall: the date of each high tide that reached the house, what was cleaned afterwards, and any new marks on the wood. Over a few weeks, this makes it easy to see whether the house is getting drier or whether one corner keeps staying damp and needs extra attention.

Common Mistakes Families Make with Wooden Houses After a Flood

• Closing the house up to keep the smell out. Shutting every window at night traps humidity inside and makes mold grow faster. Ventilation during the day matters more than keeping the smell out for a few hours.
• Moving belongings back too soon. Putting wardrobes, mattresses and boxes back against damp walls blocks airflow and creates hidden pockets where mold thrives.
• Storing wet nets under the bedroom. It is convenient, but it sends a steady stream of fishy, damp air straight up through the floor.
• Ignoring small black spots. On wood, a few small spots can mean a much larger colony under the surface. Acting early keeps the job small.
• Forgetting the neighbors. In close-knit communities, houses share walkways and sometimes walls. Coordinating clean-up with the house next door stops odor and mosquitoes from simply moving between homes.

10 Reasons Fishing Families Choose Our Service

1. Disinfection from the underfloor space to the upper rooms, treating the source of the odor, not just the symptom.
2. ULV mist reaches the gaps between floorboards, around the stilts and under the beams.
3. It uses CHEMGENE HLD4H, suitable for surface disinfection in homes.
4. Ozone treatment helps reduce fishy and musty odors in the timber that washing cannot remove.
5. A practical method for temporarily sealing the many openings of a wooden house.
6. The work day is planned around the tide table.
7. Advice on handling nets and fishing gear so they stop being a source of odor.
8. Clear ozone safety steps, including moving rubber items out.
9. Follow-up support with our mosquito spraying service for waterside communities.
10. Families can look after high-touch surfaces themselves with the CHEMGENE 750 ml spray.

Before and After: A Raised Wooden House After the Water Recedes

What the Family Said

"I used to think a wooden house would dry out on its own, but the smell from underneath just would not go away. The team had us clear out the mud first, then they fogged from the bottom up, sealed the gaps and treated one room at a time. Now when I come up the stairs I don't smell that rotten fish anymore, and my granddaughter is sleeping better."

Uncle Prasert, small-scale fisherman, Phra Samut Chedi (story from the field)

Frequently Asked Questions

1. My wooden house has lots of gaps in the floor. Will ozone treatment still work?
Yes, as long as the openings are sealed properly for the duration of the treatment. The team uses plastic sheeting over wide gaps, louvered windows and vents, then treats one room at a time so the ozone stays in long enough.

2. Does the space under the house need to be treated too?
It should be. In a raised house, the underfloor space is the source of the odor and germs. If only the upstairs is treated, the smell will rise back through the floor.

3. Will ozone damage the wood?
Treatment with a controlled dose and duration does not damage the timber itself. Rubber items such as boots, hoses and the rubber seals on equipment should be moved out, because concentrated ozone makes rubber deteriorate faster.

4. What if a high tide floods the house again after treatment?
If the water only reaches the underfloor space and drops quickly, shovel out any new mud and keep the space open to the wind. If it reaches the floor of the house again, ask the team to assess which areas need treating again.

5. Should I have my fishy nets and traps ozone-treated too?
Rinse them with clean water and dry them in the sun first, then store them away from the bedrooms. Disinfecting the storage area helps reduce germs, but some fishy smell from everyday use will always remain.

6. When can my young grandchild come back home?
Once the ventilation time set by the team has passed and there is no ozone smell left, and the child's bedding has been washed and dried completely. If the child keeps coughing or has trouble breathing, please see a doctor.

7. Do stilts that stood in water for a long time need to be replaced?
That depends on the condition of the wood. Ask a carpenter to check the base of the stilts and the beams for rot or termites. Disinfection and ozone treatment deal with germs and odor; they do not repair the structure.

Make Your Waterside Wooden Home Fresh and Restful Again

Talk to the World Health Disinfection team about an underfloor disinfection and ozone plan that fits your wooden house.

Book Ozone Treatment - Click Here

See Disinfection Service - Click Here

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

Further Reading

• Residential ozone disinfection
• Ozone treatment for odors and chemical residue
• Master Ozone Generator
• All articles
• External sources: WHO: Floods and health and Thailand Department of Disease Control