The 2026 Bang Kruai Flood: Nonthaburi's Sixth Declared District

According to Thansettakij, on 29 September 2026 Nonthaburi province declared Bang Kruai a flood disaster zone. That made Bang Kruai the sixth district, meaning every district in the province was now covered. The declaration spans seven local administrative organisations across the subdistricts of Plai Bang, Bang Khu Wiang, Maha Sawat, Sala Klang, Bang Si Thong, Bang Khun Kong, Bang Khanun, Wat Chalo and Bang Kruai. According to the same report, flooding began on 25 September 2026, driven by continuous heavy rain and a rising Chao Phraya River.

The national picture was serious too. Data from the Department of Disaster Prevention and Mitigation (DDPM), as of 06:00 on 7 October 2026, showed 27 provinces plus Bangkok affected, covering 123 districts, 984 subdistricts and 1,154,875 households, with more than 3.1 million people affected. These figures change daily, so readers should always check the latest provincial and DDPM announcements.

Many Bang Kruai homes are finished with wallpaper, gypsum partitions and plywood built-ins. These materials absorb water and dry slowly, and moisture wicks above the waterline, feeding cellulose-loving molds such as Chaetomium.

Example Case: A Living Room Where the Wallpaper Turned Grey

A typical scenario (an illustrative example, not an interview with any specific resident)

Ae lives in a two-storey townhouse in Bang Kruai with her mother, who is in her seventies, and her primary-school daughter. The downstairs living room has cream floral wallpaper, a full-wall plywood display cabinet, and a bookshelf holding several family photo albums. In late September 2026 heavy rain fell for days. Water entered the lane from around 25 September, and within a few days it seeped into the house to between ankle and mid-shin height.

About a week later the wallpaper in one corner began to bulge. It felt soft, like a sponge, and small grey-green spots appeared in clusters, some fuzzy like dull cotton wool. The bottom of the display cabinet swelled and the doors started to stick. Opening the cabinet released a smell like wet old paper mixed with soil. Ae's mother began coughing on and off while watching television, and her daughter complained of an itchy nose every time she entered the room.

Ae wiped the spots with bathroom cleaner. They faded for two days and came back in the same places. She sprayed air freshener every morning, which masked the smell briefly before the mustiness drifted back. Only when an electrician peeled off one strip of wallpaper did the family see the truth: the back of the paper and the paper facing of the gypsum board were covered in dark grey mold, a patch many times larger than anything visible from the front.

What Is Chaetomium Mold?

Chaetomium is a group of fungi widely found in soil, plant debris, animal dung and cellulose-rich materials. Its defining trait is the ability to break down cellulose, the main component of paper, wood, cotton and the paper that wraps gypsum board. In nature it is a decomposer. Inside a home that has stayed wet for a long time, it slowly digests decorative and structural materials while releasing spores and a musty odour.

What can you see? Early colonies are often white or pale grey and cottony. Over time they darken to grey-green, olive or dark brown. Sometimes you see tiny round dots like ground pepper scattered over the surface, because this mold forms small, hairy, round structures that hold its spores. Even so, you cannot identify a mold species reliably by eye. Several molds often grow together, and only laboratory sampling can confirm the species.

Where Chaetomium Hides in Bang Kruai Homes After the Water Recedes

Because Chaetomium favours cellulose, the risk points are paper, wood and natural-fibre materials that were soaked or sat close to the waterline.

• Behind wallpaper. Paste and paper are excellent food. Water trapped between wallpaper and the wall evaporates slowly, so mold grows unseen at the back before breaking through as spots.
• Gypsum board paper facing. Especially 30 to 60 centimetres above the waterline, because gypsum wicks water higher than the visible stain line.
• Plywood, particleboard and MDF in built-in cabinets, under-sink units, wardrobes and bed bases. Once swollen, the board turns crumbly, the glue weakens, and the material holds moisture for a long time.
• Skirting boards and door frames close to the floor, where water seeps behind and lingers in hidden gaps.
• Cardboard boxes, books, documents and photo albums stored on the ground floor. Wet paper packed tightly in a box grows mold very quickly.

Signs of hidden mold include blistering or peeling wallpaper, walls that feel soft when pressed, yellow or brown staining, swollen cabinets with fuzzy edges, a smell like wet paper or soil that persists even with windows open, and more sneezing, coughing or nasal itching among residents who spend time in that room.

Is Mold on Wallpaper After a Flood Dangerous? Symptoms to Watch

Indoor mold affects health mainly through breathing in spores, hyphal fragments and substances the mold releases. The World Health Organization and many public health agencies agree that living in damp, moldy buildings is associated with respiratory symptoms such as coughing, sneezing, a blocked or runny nose, throat irritation and wheezing, and that it can worsen asthma and allergies.

Symptoms people commonly report after a flood include:

• More sneezing or congestion in a room that was flooded, improving outdoors
• A dry cough and scratchy throat, especially at night or on waking
• Itchy, red or watery eyes
• Itchy skin or irritation after handling moldy materials

People who need extra care include young children, older adults, pregnant women, people with asthma, allergies or chronic lung disease, and people with weakened immunity, such as those on immune-suppressing medicines, undergoing chemotherapy or recovering from surgery. They should not do the tear-out themselves and should stay out of the house while moldy materials are removed.

Important: If anyone has a fever, difficulty breathing, wheezing, chest tightness, blood in their phlegm, or allergy symptoms severe enough to disrupt daily life, see a doctor promptly and mention that the home was flooded and has mold. Ozone treatment is home care, not medical treatment.

Why Wiping, Painting Over or Air Freshener Lets Chaetomium Come Back

Many Nonthaburi households start cleaning the moment the water drops, which is good. But some popular fixes push the problem deeper.

1. Wiping only the surface. Bleach or bathroom cleaner fades the spots, but the mold behind the wallpaper and inside the gypsum paper remains. In a few days it shows again.
2. Painting or re-papering over it. This seals moisture and mold inside the wall. The wall dries even more slowly, the smell stays, and you pay twice when it has to be torn out later.
3. Air freshener or scented candles. These mask odour without removing its source. Fragrance mixed with mustiness can irritate sensitive people even more.
4. Pointing a fan straight at moldy walls. Fans do help drying, but blowing on mold that has not been removed spreads spores through the house. Remove moldy material first, then use fans with ventilation to the outside.

Health agencies such as the CDC give consistent advice: porous materials that stayed wet for more than 24 to 48 hours, such as gypsum board, insulation, carpet, mattresses and swollen plywood, should generally be removed, because their insides cannot be cleaned reliably.

The Right Order: Remove, Clean, Dry, Then Ozone

Restoring a Bang Kruai home works best in this sequence. Ozone used before tear-out only treats air and surfaces while the source stays in the wall.

1. Safety first. Keep ground-floor power off until an electrician checks the system. Wear boots, rubber gloves, goggles and an N95 mask when removing moldy materials. Keep children, older adults and people with health conditions away.
2. Remove porous materials. Peel blistered or moldy wallpaper, cut gypsum board above the stain line as advised by a contractor, remove swollen skirting, decide whether crumbling plywood cabinets should go, and take out soaked carpets, mattresses and cushions. Bag items before carrying them through the house so spores do not spread.
3. Wash off mud and clean. Clean remaining floors and walls with water and detergent, scrubbing corners, tile grout and wall studs.
4. Dry thoroughly. Ventilate and use fans and dehumidifiers until the structure is genuinely dry. Some contractors use a moisture meter before closing walls again.
5. Ozone treatment. Once the home is clean and dry, ozone can address airborne germs, lingering mold spores and remaining musty odour.
6. Repair and redecorate only after the structure has dried properly.

How Ozone Helps with Moldy Wallpaper Rooms and Musty Odour

Ozone (O3) is a highly reactive oxidising gas. Released into a closed room, it spreads through the air and reacts with the cell structures of microbes and with odour molecules, then breaks down back into oxygen (O2). It leaves no chemical film on surfaces the way sprayed products can.

According to the company's certification data, the World Health Disinfection ozone service was tested by Thailand's Department of Medical Sciences and Intertek (UK) and eliminated the tested viruses, bacteria and fungi by 99.99%. This article does not claim test results for Chaetomium specifically. Chaetomium belongs to the fungi group the service targets, and you can request the test documents from WHD or view the certification page.

What ozone can help with in a home that had mold on wallpaper and plywood:

• Reducing airborne mold spores and germs in the room after tear-out and cleaning
• Treating surface microbes wherever the gas can reach, such as remaining wall surfaces, furniture surfaces and opened cabinets
• Reducing musty, wet-paper, earthy and muddy odours, which families notice most

What ozone does not do, stated plainly:

• It does not replace removing heavily moldy wallpaper, gypsum board, carpets, mattresses or plywood.
• It does not penetrate deep into thick materials, and it does not dry walls.
• It is not claimed to remove mold toxins (mycotoxins) within materials.
• It does not replace fixing leaks, stopping seepage, or seeing a doctor when you have symptoms.

Is Ozone Dangerous? The Safety Rules You Should Know

The ozone concentration used to disinfect a room is not suitable for breathing, so treatment happens only in an empty room. These are the rules the WHD team follows on every job.

• The room must be empty. No people, pets or plants during treatment. Aquariums should be moved or covered as the technician advises.
• The room stays closed. Doors and windows are shut, a warning sign goes on the door, and nobody enters during the cycle.
• Ventilate before re-entry. After the cycle, the ozone is allowed to break down and the room is aired for the time the technician specifies before anyone goes back in.
• Clean and dry first. Ozone works best in rooms without mud, standing water or piles of wet materials.

WHD's Post-Flood Ozone Process for Bang Kruai, Nonthaburi Homes

1. Survey and assessment. Send photos or videos of the affected rooms via LINE @whd268 or call 065-556-6294. The team asks about floor area, number of rooms, where water stood, where mold appeared and how much tear-out is done, then plans zones and quotes based on the site.
2. Confirm the home is clean and dry. The team advises what should be removed first, such as blistered wallpaper, soft gypsum or swollen plywood, and how many more days the walls may need to dry.
3. Prepare and empty the room. All people, pets and plants leave. Cabinets and drawers you want treated are opened. Windows and vents are closed.
4. Seal the room and set up. The technician places the ozone generator to suit the room size and posts a no-entry sign.
5. Run the cycle. Typically about 30 minutes per zone, depending on room size and site conditions. Multi-room homes are treated zone by zone.
6. Rest and ventilate. The machine is switched off, the ozone is allowed to break down, and the room is aired as the technician advises.
7. Re-entry and follow-up. When the technician confirms it is safe, the owner checks the smell and condition of the room and receives advice on moisture control to keep mold from returning.

WHD is based in Bang Khae, Bangkok 10160, and has no branch in Nonthaburi. Jobs in Bang Kruai and nearby areas are booked by phone or LINE according to the schedule, and same-day arrival cannot be guaranteed. Pricing is by quotation after assessment. See the full residential ozone disinfection service.

10 Reasons Bang Kruai Homes Should Consider Ozone After the 2026 Flood

1. It deals with spores stirred up by wallpaper removal. Peeling paper and cutting walls releases spores, and post-flood ozone treatment helps with the air afterwards.
2. It reduces wet-paper and earthy odours that cling to rooms even after days of open windows.
3. It reaches spots hands cannot, behind built-ins, under stairs, in ceiling voids and storerooms.
4. It leaves no chemical residue. Ozone reverts to oxygen, suitable for children's and older adults' rooms after ventilation.
5. It is backed by company certification, with 99.99% results against the tested viruses, bacteria and fungi according to the company's data.
6. It is quick per zone, about 30 minutes, so families return sooner than waiting for smells to fade on their own.
7. It follows straight on from tear-out and cleaning once the home is dry, instead of waiting weeks for odour to clear.
8. It supports confident redecorating, so new paint or paper does not seal in old smells.
9. It suits households with sensitive members, reducing airborne triggers after cleaning, alongside medical care as needed.
10. You get advice before work starts. The WHD ozone team tells you what to remove first and does not sell more than you need.

Before and After: A Room with Moldy Wallpaper

Example Case, Continued: Ae's Home After the Full Process

After seeing behind the wallpaper, Ae stopped wiping and stopped spraying fragrance. Her mother and daughter stayed upstairs behind a closed door. A contractor peeled all the living room wallpaper, cut out the soft lower gypsum, removed the skirting and took away the swollen part of the display cabinet. The wet photo albums were separated page by page and air-dried upstairs, while boxes of unneeded documents were bagged and discarded.

After several days of fans and a borrowed dehumidifier, the contractor confirmed the studs were dry. Ae booked ozone via LINE. Everyone waited at a cafe while the technician treated the living room, kitchen and under-stair storeroom zone by zone, then ventilated for the specified time.

When they returned, the wet-paper smell that had lingered for weeks was clearly reduced. Ae decided not to rush new wallpaper, choosing moisture-resistant paint for the ground floor instead, and moved all cardboard storage upstairs. She also took her mother to a scheduled doctor's appointment for her cough and mentioned the mold, which should always go hand in hand with home care. (This is an example case. Results depend on each home's condition.)

Chaetomium Recovery Checklist: Before and After Ozone

Before ozone

• Switch off ground-floor power and have an electrician inspect it
• Wear an N95 mask, gloves and goggles when removing moldy materials
• Peel blistered or spotted wallpaper and cut soft gypsum as advised
• Assess swollen plywood and particleboard and discard crumbling pieces
• Bag and remove soaked carpets, mattresses and cushions
• Wash remaining surfaces with water and detergent
• Ventilate and use fans and dehumidifiers until the structure is dry

On treatment day

• All people, pets and plants leave the area
• Open cabinets and drawers you want treated
• Remove medicines, opened food and items of concern
• Keep windows shut and do not enter during the cycle

After ozone

• Wait for the rest and ventilation time set by the technician
• Keep controlling humidity and open windows when the sun is out
• Check corners, window ledges and behind cabinets weekly for the first month
• Rebuild walls or re-paper only after the structure is fully dry
• If respiratory symptoms continue, see a doctor and mention the mold history

FAQ: Chaetomium, Moldy Wallpaper and Ozone After the Bang Kruai Flood

What is Chaetomium mold and is it dangerous?

Chaetomium is a cellulose-digesting mold that grows on paper, wallpaper, gypsum facing and plywood that stayed wet. Its spores can trigger allergies, coughing, sneezing and irritation, especially in children, older adults and people with weak immunity. Remove moldy materials and see a doctor if symptoms appear.

Should I remove wallpaper that got moldy after a flood?

Yes. The visible mold is usually the smaller part. The back of the wallpaper and the wall's paper facing often hold much more. Wiping or covering it traps moisture in the wall.

Can swollen, moldy plywood be saved?

If plywood or particleboard is swollen, crumbling or delaminating, it usually needs replacing because it holds water inside and cannot be cleaned through. Solid wood with little swelling may be cleaned and dried. Ask a contractor to assess.

Does ozone get rid of mold?

According to the company's certification data, the WHD ozone service achieved 99.99% against the tested fungi, bacteria and viruses. Ozone helps with airborne spores, surface microbes and musty odour, but it does not replace removing heavily moldy materials and drying. Ask WHD for the test data.

Is ozone dangerous? Can I stay home during treatment?

Do not stay in the room. It must be empty of people, pets and plants, closed for the whole cycle, and re-entered only after rest and ventilation as the technician directs. Following this makes it safe.

How much does ozone treatment cost?

It depends on floor area, number of rooms and site conditions. WHD provides a quotation after assessment. Send photos via LINE @whd268 or call 065-556-6294.

Is there an ozone service near me in Bang Kruai, Nonthaburi?

WHD is based in Bang Khae, Bangkok, with no Nonthaburi branch, but it books jobs in Bang Kruai and nearby areas by phone or LINE according to its schedule. Same-day arrival cannot be guaranteed.

How long does ozone treatment take?

About 30 minutes per zone, plus rest and ventilation before re-entry. Larger homes are done zone by zone, so total time depends on size.

The musty smell will not go away after the flood. What should I do?

Find the source first, usually wallpaper, gypsum, carpet, mattresses or cabinets that are still wet. Remove and dry them, then use ozone to reduce lingering odour. Air freshener only masks it.

Moldy Wallpaper, Swollen Plywood or Musty Smells in Bang Kruai After the 2026 Flood? Talk to WHD

Send photos of the room, the moldy areas and the floor size, and the team will help you decide what to remove first and when ozone makes sense.

See the Post-Flood Ozone Service

Call 065-556-6294 | LINE @whd268

World Health Disinfection, Bang Khae, Bangkok 10160. Upcountry jobs booked by phone or LINE. Pricing by quotation.

Related Links and References

• Residential and building ozone disinfection service
• Ozone cleaning service
• Company certification documents
• Contact us
• Thansettakij (29 Sep 2026): Nonthaburi declares Bang Kruai a flood disaster zone
• Government Public Relations Department: DDPM flood situation as of 7 Oct 2026
• CDC: Floods and cleanup safety
• Department of Disease Control, Thailand

Note: area details and figures follow the dates given in news and DDPM reports and change daily. This article is general information, not medical advice.