A Story From the Field: Three Weeks Before Term, and a Dormitory That Is Not Ready

Khru Wilai is the housemistress of the girls' dormitory at a private school in Wiset Chai Chan district, Ang Thong province. The school takes boarders from lower to upper secondary level, and many of its students come from other districts and provinces. The dormitory is a three-story building. On the ground floor are shared bedrooms, a shared bathroom block, a laundry room and the staff room. During the 2026 floods, which arrived while school was on its mid-year break, water from the Noi River flooded the ground floor to about knee height for almost two weeks.

When the water receded, Khru Wilai and the school caretaker opened the doors of the ground-floor bedrooms. A thick, damp smell hit them immediately. The foam mattresses on the lower bunks of the steel bunk beds had soaked up so much water that they were too heavy to lift alone. The plywood lockers had swollen and were growing green mold along their edges. The white-painted walls carried a straight tide line along the full length of each room. In the shared bathrooms the grout between the tiles had turned dark, and the floor drains gave off a foul smell. In the canteen next door, mud had dried under every one of the long tables.

What worried Khru Wilai most was not the damage to furniture. It was a message in the parents' LINE group. The mother of a Year 7 student with allergies and asthma had written, "Will the dormitory be safe for my daughter? If there's still mold, she won't be able to sleep there." Several other parents followed with the same question: what exactly was the school planning to do? The school's leadership needed a clear answer, and it needed the work done before the second semester began.

This is an illustrative scenario based on the kinds of problems commonly found after floods. It does not describe any specific school. Health information in this article is general knowledge; anyone with unusual symptoms should see a doctor.

Why a Boarding Dormitory Needs More Than a Classroom After a Flood

A classroom is used for a few hours a day. A dormitory is a student's home around the clock. Children sleep, shower, wash their clothes and eat within the same small set of buildings, and many share a room with several others. Any mold or germs left behind by floodwater therefore have the chance to affect many young people at the same time, night after night.

Dormitories also contain far more soft, absorbent material than a classroom: mattresses, pillows, blankets, curtains, towels and clothes stored in lockers. Every one of these can hold moisture and odor long after the floor looks dry. That is why dormitory recovery needs to be planned room by room rather than handled as a quick wash-down.

1. Students with allergies and asthma

Mold spores in a bedroom where the windows are closed at night can trigger a blocked nose, a lingering cough, itchy eyes and asthma attacks. Students who already have a medical condition are affected first. When a child cannot sleep well, concentration in class suffers too, and teachers may notice a dip in energy and performance without realizing that the cause is the room the student sleeps in.

2. Shared bathrooms and laundry rooms

A shared bathroom that was flooded may still carry bacteria from wastewater in tile grout, pipes and floor drains. That raises the risk of skin infections, athlete's foot and stomach illness. Laundry rooms that stay damp all the time are a favorite place for mold, which leaves freshly washed uniforms smelling musty and can spread to the lockers where clothes are stored.

3. The canteen and kitchen

A canteen that cooks three meals a day for hundreds of students must be sure that food preparation surfaces, utensils and drains are genuinely clean. Otherwise diarrhea and food poisoning can spread through the whole school in a matter of days, and the disruption to classes and boarding life can be severe.

4. The staff doing the cleaning

Caretakers and housekeepers who shovel mud need to watch out for leptospirosis, an infection spread through water and soil contaminated with animal urine, especially when they have cuts on their hands or feet. Rubber gloves and boots should be worn every time, and anyone who develops a fever, muscle pain or headache after flood clean-up should see a doctor and mention that they have been in contact with floodwater.

5. Parents' trust and the school's reputation

For a private school, parents' trust is the foundation of next year's enrollment. If a child goes home with a cough and says the dormitory smells musty, the news spreads through parent groups very quickly. A clear, explainable restoration plan protects both students and the school's good name. It also gives teachers something concrete to say when parents ask questions.

What Schools Often Try, and Why It Is Not Enough

• Drying mattresses in the sun and putting them back: Foam mattresses that sat under water for days usually carry contamination deep into the core. Sunlight dries only the outer layer. These mattresses should normally be replaced, while those that were only exposed to damp can be restored.
• Pouring bleach throughout the bathrooms: The grout may look whiter, but the sharp fumes irritate the lungs in a closed space, and bleach does nothing about the musty odor in the bedrooms next door.
• Spraying air freshener in the bedrooms: Fragrance covers the smell for a few hours. Some scented products can also make sensitive students' symptoms worse.
• Running ceiling fans all day: Fans help things dry faster, but they also lift mold spores into the air and spread them across the room, onto the brand-new bedding that has just been brought in.
• Repainting the walls straight away: If the walls are still damp, the paint blisters and mold returns within a few weeks, after the students have already moved back in, which makes it much harder to fix.

Each of these steps does part of the job. What is missing is thorough disinfection of every surface and a systematic way to deal with mold and odor in the air of the bedrooms where students breathe all night.

The Solution: Ozone for Bedrooms and Disinfection Fogging for the Whole Dormitory, by World Health Disinfection

World Health Disinfection (WHD) plans dormitory recovery in two complementary parts. The first is our disinfection fogging service using Chemgene HLD4H applied through ULV (ultra-low volume) foggers, covering bedrooms, shared bathrooms, the laundry room, the canteen, corridors and stairways. The second is our ozone treatment service for bedrooms and staff rooms that can be sealed. Ozone is a gas that spreads throughout a closed room, helping to reduce mold spores in the air and on curtains, lockers and any bedding that is being kept, while breaking down the molecules that cause musty odor.

Fogging and ozone each have their strengths. Fogging places disinfectant directly on surfaces that students touch every day, from bunk-bed rails to bathroom taps. Ozone works on the air and reaches into places a cloth or a spray cannot, such as the inside of a locker, the folds of a curtain or the gap behind a wardrobe. Together they give housemasters and housemistresses confidence that the whole room has been treated, not just the parts that are easy to see.

Step-by-step process

1. Site survey: We check how high the water rose, where mold is growing, how damp the walls, lockers and bedding are, and advise which items should be discarded and which can be restored.
2. Mud removal and sorting advice: Mud and wet rubbish are removed, mattresses that were submerged for a long time are set aside for disposal, and steel bed frames and floors are washed with clean water and detergent. Staff wear gloves, boots and masks.
3. Disinfection fogging with Chemgene HLD4H: We fog bedrooms, beds, lockers, shared bathrooms, the laundry room, the canteen and stair rails, focusing on areas that were flooded and on the surfaces students touch most often.
4. Controlled ozone treatment for bedrooms: Each room is sealed, the ozone generator is sized to the space, and concentration and duration are set to suit the materials inside.
5. Ventilation: Windows are opened and extraction fans run for the time our team specifies, before new bedding is brought in and before anyone re-enters.
6. Re-check: We assess odor and surface condition again and advise on humidity control throughout the semester.

Safety first: High concentrations of ozone irritate the respiratory system. During treatment there must be no students, teachers, pets or plants in the area, and the space must be ventilated thoroughly before anyone returns. We recommend completing the work before students move back in. Electronic equipment such as computers and sound systems, and personal items with ozone-sensitive rubber parts, are switched off, removed or covered, and our team keeps the ozone dose no higher than necessary.

For the canteen, after fogging we advise rinsing food-contact surfaces with clean water in line with the product directions before cooking resumes. For mattresses and pillows that are being kept, our dust mite removal service can be added to reduce accumulated dust and mites.

Planning the Work Around the School Calendar

Timing matters as much as method. Thai schools usually have a short break between the first and second semesters, and floods in 2026 overlapped with that period in many provinces. That gives schools a narrow but valuable window to restore dormitories while they are empty.

A practical sequence many schools follow looks like this. In the first week after the water drains, caretakers remove mud, sort damaged furniture and bedding, and arrange for plumbers and electricians to check the ground floor. In the second week, the professional disinfection and ozone treatment takes place, zone by zone, starting with the dormitory and canteen. In the final days before term, rooms are ventilated, new mattresses and bedding are delivered, and housemasters walk through every room to confirm that it smells fresh and looks dry.

Leaving a few days between treatment and the students' return also gives the school time to respond if any room needs a second look. A wall that was wetter than expected, or a locker that still smells, can be dealt with calmly rather than in a rush on the morning students arrive with their suitcases.

Communicating with parents

Parents do not need technical details, but they do appreciate a short, honest summary. A message in the parents' group that lists the steps taken, from mud removal and replacing damaged mattresses to disinfection fogging, ozone treatment of bedrooms and ventilation before students return, answers most questions before they are asked. Schools that share a brief update with a photo of the cleaned rooms often find that worried messages turn into thanks.

Room-by-room notes for a boarding house

Bedrooms: Steel bunk frames can be washed and disinfected, but slatted wooden bases that stayed wet may need replacing. Check under the lowest bunk, where mud and moisture collect out of sight, and look inside every locker, including the back panel that touches the wall.

Shared bathrooms: Pay attention to shower drains, the base of toilet bowls, the silicone around basins and the joints where walls meet the floor. These are the places where wastewater lingered longest. Replace shower curtains and bath mats rather than trying to rescue them.

Laundry room: Washing machines that were submerged must be checked by a technician before use. Clean the drum and the detergent drawer, and run an empty hot cycle once the machine is confirmed safe. Drying racks and laundry baskets should be washed and disinfected.

Staff and study rooms: These rooms often hold books, files and electronics. Wet paper that cannot be saved should be removed, and electronics should be taken out or covered before ozone treatment. A study room that smells fresh helps students settle back into homework routines quickly.

Common areas and stairways: Handrails, light switches, door handles and water dispensers are touched by every student, several times a day. Including them in the fogging plan is simple, but it makes a real difference to how many hands carry germs from room to room.

Outdoor areas around the dormitory: Flowerbeds, drains and the space under covered walkways often hold standing water after a flood. Clearing debris and draining these spots reduces mosquito breeding near the rooms where students sleep, and keeps mud from being tracked back into freshly cleaned corridors.

10 Reasons Boarding Schools in Ang Thong Choose WHD to Restore Their Dormitories

1. We understand spaces where children live all day, and plan bedrooms, bathrooms, laundry and canteen together in one visit.
2. Two methods working together: surface disinfection fogging plus ozone treatment for bedrooms that can be sealed.
3. ULV fine-droplet fogging reaches under bunk beds, behind lockers and into bathroom grout lines.
4. A disinfectant our team uses every day: Chemgene HLD4H, designed for surface disinfection work.
5. Odor removed at the source, not covered with fragrance. Learn more about ozone disinfection for living spaces.
6. Care for students with allergies, with clear ventilation times and advice on ongoing humidity control.
7. Honest advice on bedding, telling you what to discard and what can be restored, plus our dust mite removal service.
8. Scheduled before term starts, while the dormitory is empty, so students are not disrupted.
9. Complete follow-up options such as a mosquito spraying service around dormitories and sports fields to reduce dengue risk.
10. Easy to reach. Call 065-556-6294 or LINE @whd268 to book a survey in Wiset Chai Chan and across Ang Thong.

Customer Voices (Illustrative Scenarios)

"What helped us most was knowing what to throw away and what we could keep. The team fogged the whole dormitory and ran ozone in the bedrooms before we put in the new mattresses. When the students came back, the rooms no longer smelled musty."
— Khru Wilai, girls' dormitory housemistress, private school in Wiset Chai Chan

"The school shared its dormitory restoration steps in the parents' group. Reading them put my mind at rest. My daughter, who has asthma, went back to boarding as normal."
— Parent of a Year 7 student

Dormitory Care Checklist for the Whole Semester

• Open bedroom windows during the day and have students air their bedding once a week.
• Do not allow wet clothes or towels to be stored inside lockers.
• Clean bathroom grout and floor drains on a fixed schedule.
• Run a dehumidifier in the laundry room and any room that feels damp.
• Inspect roofs and walls for leaks and repair them before next rainy season.
• Turn over containers and remove standing water around the dormitory to reduce mosquitoes.
• Ask students to tell a teacher immediately if they notice mold spots or a musty smell in their room.
• Include a short humidity and mold check in the housemaster's weekly room inspection.

Building these habits into dormitory life helps students take ownership of their rooms and keeps small problems from growing into another major clean-up.

Frequently Asked Questions

Q: Can a mattress that was underwater be used again after ozone treatment?
A: Foam mattresses that were submerged for several days usually carry deep contamination, so we recommend replacing them. Mattresses that were only exposed to damp or splashes can be cleaned and treated with ozone, combined with dust mite removal.

Q: When can students move back in after ozone treatment?
A: After the full ventilation time our team specifies, which depends on room size and airflow. We recommend finishing the work at least two or three days before the semester starts.

Q: Will ozone damage computers or fans?
A: We control both dose and duration. Equipment is switched off and unplugged, and anything sensitive to ozone or containing rubber parts is removed or covered.

Q: Can the whole school be done in one day?
A: It depends on the size of the campus. Most schools are treated zone by zone, starting with the dormitory and canteen, then the ground floor of the teaching buildings.

Q: How should the school explain the work to parents?
A: A short summary that mentions mud removal, discarding damaged bedding, disinfection fogging, ozone treatment and ventilation before students return will reassure most parents.

Q: Do teachers need to be on site during the work?
A: A staff member should be available to open rooms and confirm which items stay or go, but nobody should remain inside rooms during ozone treatment.

Q: Which areas do you serve?
A: Wiset Chai Chan, Mueang Ang Thong, Pa Mok, Pho Thong, Samko and nearby provinces. Contact us on LINE @whd268.

Make the Dormitory a Safe Home for Your Students Again

Book a site survey for your school's boarding dormitory and canteen in Wiset Chai Chan and across Ang Thong.

Book Ozone Treatment – Click Here

See Disinfection Service – Click Here

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

Related Links

• Ozone disinfection for living spaces
• Dust mite removal service
• Master Ozone Generator
• All articles

Health reference: World Health Organization (WHO): Floods · Department of Health, Thailand