A typical scenario: a wooden shophouse guesthouse in Trat town, two months before the first guests

Auntie Nid (not a real person) runs a small guesthouse in a two-storey wooden shophouse in Trat's old quarter. Downstairs is a café and reception; upstairs are six rooms, mostly booked by travellers who stay one night before heading to the pier for the islands. In late September it rained for days, and water from the street rose into the ground floor, soaking the wooden floor, table legs, the fridge and the shared guest bathroom.

When the water dropped, she and her nephew swept out the mud, washed the floor and left the doors open. But a row of joined wooden shophouses does not ventilate well. Within days the bottom of the wooden walls turned grey-green, the space under the stairs smelled strongly musty, the shared bathroom gave off drain odours, and her nephew, who had waded through water for two days moving stock, developed a fever and aching legs and had to be taken to hospital.

Her worry is the coming high season. One review saying "the room smelled damp" or "I got sick after staying here" could quieten a whole season. Her question: "We have washed and aired it. How do we make sure the germs are really gone?"

Note: this is a typical scenario based on common post-flood situations, not an interview with a real person. Anyone with high fever and calf pain after wading in floodwater should see a doctor at once because of leptospirosis risk.

Flooded areas in Trat according to DDPM, 2 October 2026

According to the DDPM report of 2 October 2026, three districts of Trat were affected, totalling 1,310 households, with water levels falling.

These figures describe 2 October 2026 and change daily; renewed heavy rain could push water up again in places, so follow provincial and district announcements. Nationally, DDPM reported the same day that floods affected 31 provinces plus Bangkok, 1,245,581 households and 3,535,206 people, caused by heavy to very heavy rain and runoff. What stands out in Trat is the mix: rural orchard communities in Bo Rai and Khao Saming, and a trading, administrative and tourist hub in Mueang Trat.

Why Trat needs to spray shared places as well as homes

Shared places are where people from many families and districts meet. Germs left there travel back on hands, shoes and food to homes that were just cleaned. Places to plan for:

• Guesthouses, hostels and homestays in Trat town: new guests daily, shared bathrooms, linen and lounges. Norovirus spreads very fast in this kind of lodging.
• Fresh and evening markets: seafood and vegetable stalls, curry-rice shops and drains are damp and organic-rich even on normal days.
• Restaurants, cafés and street-front shophouses: old wooden rows ventilate poorly, letting water soak into floors and lower walls.
• Passenger pick-up points and van or tour offices: waiting chairs, ticket counters and toilets see heavy traffic in high season.
• Schools and child development centres in all three districts: small children face hand-foot-mouth disease, RSV and viral diarrhoea.
• Temples and village halls: used as shelters and aid points, with constant foot traffic.
• District offices, subdistrict offices and health promoting hospitals: counters and waiting chairs are shared touch points.
• Produce sheds in Khao Saming and Bo Rai: baskets, crates and sorting tables need cleaning before the next fruit season.

Our earlier ozone article for Trat focused on closed rooms in homes. This one looks at large, semi-open spaces and surfaces many people touch, where spraying is the better fit.

The many kinds of germs after the Trat floods: bacteria, viruses, mold and odour

Floodwater in Trat carried orchard runoff, town drainage, septic-tank overflow, rubbish and small dead animals into buildings. When it drained away, the germs stayed on surfaces and inside materials.

Bacteria

• E. coli and faecal bacteria: contaminate floors, bathrooms, chopping boards and dishes, causing diarrhoea, cramps and vomiting; the main risk for restaurants and guesthouses that reopen quickly.
• Salmonella: found in contaminated water and badly stored food. Seafood and fresh food from fridges that lost power should be thrown away.
• Leptospira (leptospirosis risk): present in water and mud mixed with animal urine, entering through cuts or soaked skin. Orchard workers in Bo Rai and Khao Saming and townspeople who moved goods through water are at risk. Watch for sudden high fever and calf pain.

Viruses

• Norovirus and rotavirus: sudden vomiting and diarrhoea, spread via hands, door handles, taps and food; a nightmare for tourist lodging and schools.
• Hand-foot-mouth disease virus: common in nurseries and kindergartens, spread through toys and tables.
• RSV and influenza: damp air and crowded shelters help respiratory viruses spread, especially to small children and older adults.

Mold and airborne spores

In a province as rainy as Trat, mold arrives fast and stays. It can start growing on wet materials within about one to two days, which is why CDC and the World Health Organization advise cleaning and drying within 24 to 48 hours. Spores cause congestion, sneezing, coughing, red eyes and asthma attacks, and can cause more serious infection in people with weak immunity.

Musty and drain odours

A smell that will not leave a wooden shophouse or guest room means moisture and microbes are still active. Perfume and scented candles do not fix the cause, and guests notice immediately.

Who is most at risk

Young children, older adults, pregnant women, people with chronic illness or wounds, orchard workers, market vendors standing on wet floors all day, and lodging or restaurant staff who clean shared bathrooms. Anyone with high fever, calf pain, severe diarrhoea, yellowing skin or breathing difficulty should see a doctor immediately. Spraying reduces germs in the environment; it is not medical treatment.

Mold in Trat's wooden shophouses and orchard homes: why it comes back after washing

Many buildings in Trat are wooden or part-wood, and town shophouses are often decades old, joined wall to wall with few vents. Wood wicks water up its grain above the visible waterline and takes a long time to dry, which is why mold reappears days after wiping.

• Wooden floors and walls: water seeps into joints and under boards; open them to airflow and lift a few boards if possible.
• Under stairs and storerooms: dark, stale and full of cardboard or old cloth, where mold grows thickest.
• Mattresses, curtains and rugs in guest rooms: replace them if soaked; washing or spraying cannot clean the core.
• Crates, baskets and sacks in produce sheds: discard deeply moldy wooden crates; wash and sun-dry plastic baskets.
• Papers and books in schools and offices: separate wet items at once and dry what must be kept in a ventilated space.

The correct order is discard, wash with detergent, dry, then spray, followed by ventilation and monitoring, because spraying does not dry wood that is wet inside.

What Trat risks if germs are left behind

Health: diarrhoea spreading through households, children passing illness around at school, flaring allergies in older relatives, and leptospirosis risk for anyone who waded through water.

Income: Trat depends on orchards and tourism. A guesthouse or restaurant that reopens late, or whose customers fall ill, can lose the start of the most important season, while farmers must ready sheds for the next harvest.

Costs: medical bills, new bedding, and potentially large repair bills if mold spreads into the timber of old shophouses.

Reputation: for businesses that live on online reviews, a few comments about damp smells or sickness can affect bookings for a whole season.

Community: the feeling that the market or school is not yet safe slows the return to normal life.

Common fixes that are not enough for Trat's lodging, markets and schools

• Hosing down and closing up to dry: a closed shophouse gets mustier and mold grows faster.
• Strong bleach on the floor: harsh fumes in poorly ventilated rooms, dangerous if mixed with toilet cleaners or ammonia, and it misses vertical surfaces and touch points.
• Incense, scented candles and air freshener: they mask odour but leave germs on surfaces.
• Painting or wallpapering over stains: mold keeps growing underneath and pushes through again.
• One cloth for every room: an unchanged cloth can carry germs from the bathroom to bedrooms or the kitchen.

None of these is useless, but none is designed to cover large areas and several germ groups at once. Professional spraying after cleaning closes that gap.

WHD disinfection spraying for Trat: how ULV mist and CHEMGENE HLD4H reach surfaces after cleaning

World Health Disinfection (WHD) provides disinfection spraying for homes, buildings and public spaces. According to the service information, trained technicians spray and/or use ULV (Ultra Low Volume) fogging, which breaks the disinfectant into very fine droplets. The mist settles across a room, on wooden floors and the gaps between boards, lower walls, table legs, under beds, stair rails and behind cabinets, places hand wiping often misses.

Spraying works best after mud is removed and surfaces are washed, because mud and grime shield germs from the disinfectant. On clean surfaces, the droplets make direct contact.

The disinfectant is CHEMGENE HLD4H, a medical-grade product from the United Kingdom containing Benzalkonium Chloride and Didecyldimethylammonium Chloride. According to the service information, it covers viruses, bacteria and fungi, including COVID-19, RSV, H1N1, H5N1 and hand-foot-mouth disease virus, with a stated efficacy of 99.99%. The service page lists approvals or endorsements from Thailand's Department of Medical Sciences, Mahidol University, NHS England and EN 14476:2013+A2:2019.

How it works

1. Book: call 065-556-6294 or LINE @whd268 with the district (Bo Rai, Khao Saming or Mueang Trat), type of premises, number of rooms or floor area, and photos.
2. Prepare: remove mud, wash floors and walls, discard ruined items, and put away food, dishes, clean linen and personal items.
3. Spray: people, guests and pets leave the zone being sprayed; technicians work from the far end towards the door.
4. Wait about 30 minutes: according to the service information, then re-enter when the technicians advise.
5. Ventilate: open doors and windows and resume normal use.

Coverage: WHD is based in Bang Khae, Bangkok, and has no branch in Trat. Jobs in Bo Rai, Khao Saming and Mueang Trat are planned by phone or LINE, with travel date, scope and cost confirmed in advance. Same-day arrival cannot be promised. Grouping several sites, such as neighbouring guesthouses or several schools in one district, makes planning easier.

For guest rooms where a musty smell lingers in the air after spraying, residential ozone disinfection can be added.

Promotion: according to the service information, customers receive a free CHEMGENE spray bottle and WELLGIENIC wet tissues, and a tax invoice is available.

Spraying plans for each kind of place in Bo Rai, Khao Saming and Mueang Trat

• Guesthouses in Trat town: replace soaked mattresses, curtains and rugs; wash shared bathrooms, drains and ground-floor boards; air for several days; then spray rooms, bathrooms, stairs and lounges before taking bookings. Keep a note of the dates in case guests ask.
• Markets, seafood stalls and restaurants: discard food touched by water or spoiled by power cuts, wash boards, trays, chillers and drains, and spray after closing with all food removed or covered.
• Orchard homes in Bo Rai and Khao Saming: ground-floor bedrooms, kitchen, bathroom and the space under raised houses; keep farm chemicals out of the spray zone.
• Produce sheds: discard moldy crates, wash baskets, tables and scales, spray when no produce is present, and rinse food-contact surfaces as advised before the next harvest.
• Schools and child centres: classrooms, toilets, canteen and nap rooms first; discard soaked mats, wash plastic toys, spray on a day with no children.
• Temples, district offices and health centres: clear shelter bedding and food waste, then spray counters, chairs, rails and public toilets outside service hours.
• Pick-up points and tour offices: waiting chairs, counters, toilets and door handles before the season starts.

10 reasons Trat chooses disinfection spraying after the flood

1. Ready before high season: lodging and restaurants in Trat town can prepare before the first guests arrive.
2. Several germ groups at once: the service page says the disinfectant covers viruses, bacteria and fungi.
3. Fine mist reaches wood joints: suited to wooden shophouses and homes with many gaps.
4. Medical-grade disinfectant: disinfection spraying with CHEMGENE HLD4H from the United Kingdom.
5. Clearly stated endorsements: Department of Medical Sciences, Mahidol University, NHS England and EN 14476, per the service page.
6. About a 30-minute wait: according to the service information, so businesses need not stay closed for days.
7. Shared bathrooms covered: lowers the risk of gut viruses in guesthouse and market toilets.
8. Proof for guests and parents: a tax invoice for the spraying service is available.
9. Free follow-up items: CHEMGENE spray bottle and WELLGIENIC wet tissues for daily touch-point wiping.
10. Trained technicians: according to the service information, customers include hospitals, schools, malls, airports, offices, airlines, banks and residential buildings.

Before and after spraying in Trat guesthouses and shops

Results depend on cleaning, drying and ongoing care. If wood or walls stay wet inside, mold can return.

Example case: a community market and curry-rice stall in Khao Saming

Daeng (a fictional name) sells curry and rice at a small community market in Khao Saming: about twenty stalls under a tin roof, with a concrete floor and a drain at the back. Floodwater from the drain and surrounding land covered the floor for several days. After vendors swept and hosed it, smells still drifted from the drain, mold grew under wooden stall tops, and regular customers said they would wait until the market was cleaner.

The market committee agreed to act together. Every stall discarded soaked wooden boards, washed with detergent, the drain was cleared of mud, and the market was left open to dry for two days. They then sent photos and the market size to WHD on LINE. The team scheduled the trip in advance and sprayed one afternoon after closing, covering stall floors, table legs, under-stall spaces, toilets and handwashing points. After the advised wait, vendors set up for the next morning.

What brought customers back was not a "100% germ-free" sign, which nobody can promise, but the committee explaining each step in the community group and putting soap and a handwashing station at the entrance.

Note: this is an illustrative example case. Names and details are fictional.

Trat flood recovery checklist, before and after spraying

Before

• Cut power to flooded areas and have an electrician check, especially old wiring in wooden shophouses.
• Wear boots, rubber gloves and a mask; cover wounds.
• Remove mud and wash hard surfaces with detergent.
• Discard soaked mattresses, rugs, curtains, moldy materials and any food touched by water or spoiled by power cuts.
• Move farm chemicals out of the area; ventilate and dry; send photos to LINE @whd268.

On the day

• People, guests and pets leave the zone; food, dishes and personal items are put away.
• Wait about 30 minutes and re-enter when the technicians advise.

After

• Ventilate daily and watch damp spots for one to two weeks; wipe shared bathrooms and counters with the free spray.
• If mold or smell returns, find the moisture source, then consult the team.
• Anyone with high fever, calf pain or severe diarrhoea should see a doctor immediately.

FAQ: post-flood disinfection spraying in Trat

Does WHD have a branch in Trat?

No. WHD is in Bang Khae, Bangkok. Work in Bo Rai, Khao Saming and Mueang Trat is planned by phone on 065-556-6294 or LINE @whd268, with the travel date confirmed in advance. Same-day arrival cannot be guaranteed.

Some guest rooms are occupied. Can you still spray?

Yes, by zones. Guests must not be in any area being sprayed and return when the technicians advise. The simplest option is to spray before reopening.

Can wooden floors be sprayed?

Yes, once washed and reasonably dry. The team will advise on preparation.

Will mold never return?

That cannot be guaranteed. If timber stays wet inside or leaks continue, mold may return, so tackle moisture and ventilation too.

Spraying or ozone?

Spraying suits surfaces and shared spaces. Ozone treatment works in closed, empty rooms for airborne odour. Many lodgings use both.

Someone got sick after wading. What now?

See a doctor immediately and mention the flood exposure, especially with high fever and calf pain. Spraying is not medical treatment.

Book post-flood disinfection spraying in Trat for homes, guesthouses, markets and schools in Bo Rai, Khao Saming and Mueang Trat

Tell us the district, type of premises and floor area, and send photos. The team will assess and plan the travel date with you.

Book disinfection spraying in Trat

Call 065-556-6294 · LINE @whd268

Related links

• World Health Disinfection spraying service
• CHEMGENE HLD4H disinfectant
• Residential ozone disinfection

References

• Bangkokbiznews, flood situation based on DDPM data: bangkokbiznews.com/news/news-update/1254629
• Thai PBS flood report: thaipbs.or.th/news/content/558960
• World Health Organization fact sheets: who.int/news-room/fact-sheets
• CDC Floods: cdc.gov/floods
• Department of Disease Control, Thailand: ddc.moph.go.th