A Story from the Field: The Unit That Used to Be the Best in the Building

Prae is thirty-six. Three years ago she bought a ground-floor unit in a condominium off the Bang Na-Trat Road in Bang Phli district, Samut Prakan. The sales team called it a "pool-access" unit: slide open the glass door, step onto a small timber deck, and you are at the edge of the swimming pool. She paid noticeably more than the price of a unit on a higher floor because she loved the idea of waking up to the sound of water and reading by the pool in the evening breeze.

During the heavy October 2026 floods, days of non-stop rain combined with street water that the drains could not carry away. The pool deck flooded, the pool itself rose over its edge, and murky, tea-colored water crept in along the bottom track of her sliding door. It covered her floor to roughly the height of a hand span and sat there for almost three days. Prae moved in with her sister, who lives on a high floor in another tower.

When she finally returned and opened her front door, the first thing that hit her was a smell: a blend of mud, chlorine and stale damp. Her laminate floor had swollen and buckled. A long line of black spots ran along the bottom edge of the built-in wardrobe in the bedroom. The heavy floor-length curtains carried a tide mark. And in the track of the sliding door sat a grey-green slime that no amount of scrubbing seemed to remove. She wiped, she mopped, she ran the air conditioner, she opened the door to let the breeze in. A week later, the smell was still back every single morning. The unit that had once been the most desirable in the building had become a room she did not want to sleep in.

Prae is not alone. Pool-access units and podium-level units in many condominiums around Bang Phli, Bang Na and Bang Sao Thong found themselves in the same situation once the water went down. These units have specific weak points that higher units simply do not have. This article explains what those weak points are, and how to restore the unit properly so that the musty smell and mold are actually gone, rather than just hidden for a few days.

Why Pool-Side Units Suffer More Than Other Units in the Same Building

An upper-floor unit that the water never reached may only face humidity from the air. A pool-access unit faces several problems stacked on top of each other, which is why the odor and mold go deeper than what you can see on the surface.

• The water that came in was not clean rainwater. When the pool overflows and water from the car park or street mixes in, it carries silt, mud, leaves, litter and germs from the drainage system straight into the unit.
• Sliding door tracks are moisture traps. Aluminum tracks have grooves and tiny weep holes that clog easily with sediment. When water sits in the track, mold and bacteria form a slime layer that releases odor around the clock.
• Laminate and engineered wood floors hide water underneath. Water seeps beneath the planks and into the foam underlay, creating a hidden wet layer that will not dry on its own while the floor is still in place.
• Built-in furniture is usually plywood or particleboard. The lower edges of wardrobes and kitchen cabinets wick water several centimeters upward, giving mold an ideal food source.
• The pool adds humidity all year round. Even on a normal day, a pool-side unit is more humid than other units. After a flood on top of that, it dries much more slowly.
• Chlorine smell masks mold. Many people assume that a chlorine smell means "clean." In reality, the mixed odor can hide the early warning signs of mold that is actively growing.

Put all of this together and you have a unit that looks mostly fine after a quick clean but keeps producing odor from places you cannot easily reach. That is exactly why so many owners say, "I have cleaned it three times and it still smells."

The Real Cost: Health, Money, Property Value and Time

Health. Standing floodwater can carry bacteria that cause diarrhea, as well as the organisms associated with leptospirosis, onto the surfaces inside the unit. Mold growing along cabinet edges, drywall and under the floor releases spores into the air. These can trigger allergies, sneezing, a blocked nose, itchy eyes, and make asthma flare up more easily. If anyone in the household develops unusual symptoms, please consult a doctor. This article is not medical advice.

Money. Pool-access units are often finished with higher-end materials: wood floors, heavy fabric curtains, upholstered sofas and full-wall built-in storage. The longer mold is left to spread, the higher the repair bill becomes, because items that could have been saved turn into items that must be thrown away.

Property value. Many pool-access units in Bang Phli were bought as rental investments. A prospective tenant only needs a few minutes in the room to notice a musty smell. Renting the unit out at the previous price becomes difficult, and a single comment in a rental group can leave the room empty for months.

Time. Most owners have full-time jobs. They take leave to clean again and again, and the smell still will not go away. Frustration builds up, and many end up simply locking the unit and leaving it closed. Unfortunately, a closed, humid room is exactly the environment in which mold grows fastest, so the problem quietly becomes worse.

Why DIY Fixes Usually Fail in Pool-Side Units

• Pouring bleach on floors and tracks. Bleach only works where it physically touches. It does not reach beneath floor planks or inside plywood. The fumes irritate the nose and throat, and repeated use can degrade aluminum edges and rubber seals.
• Opening the door to the pool for fresh air. Air from the pool deck is already humid. Leaving the door open all day can add moisture rather than remove it.
• Running the air conditioner at full blast. This does reduce humidity in the air to some extent, but if the AC coil pulls in spores, the unit itself becomes a machine that spreads the musty smell to every corner.
• Air fresheners and scented candles. They mask the smell for a few hours. The source is still there.
• Repainting or re-laminating straight away. If the material underneath is still damp, mold will push the paint into bubbles and return as black spots within weeks.

What a pool-side unit really needs is a proper sequence: remove and dry first, then disinfect every crevice with a fine mist, and finish with ozone treatment to deal with odor trapped in the air and on the surface of materials. Skipping a step is usually why the smell comes back.

The Solution: Chemgene HLD4H Disinfection Fogging + Ozone Treatment by World Health Disinfection

World Health Disinfection (WHD) provides a disinfection fogging service using CHEMGENE HLD4H delivered through ULV (ultra-low volume) fogging equipment. The machine breaks the solution into an extremely fine mist that drifts into door tracks, under cabinets, behind curtains and into the upper corners of the ceiling, all places a cloth simply cannot reach. After that comes ozone treatment, which helps destroy airborne mold spores and break down the odor molecules that have soaked into fabrics and the surface of materials.

Our Step-by-Step Process for Pool-Access Units

1. Site survey with the owner and the juristic person (building management). We check the water line, the sliding door track, cabinet edges, floors, drywall and air-conditioning, and we ask management when the pool system and the surrounding deck will be cleaned. Work inside the unit is most effective once the shared area around it is clean.
2. Advice on removal and mud clean-up. We recommend that a contractor removes swollen laminate flooring, foam underlay and any built-in panels that have absorbed water. Mud should be washed out of the tracks and the weep holes cleared. Mattresses or sofas that sat in water for a long time should be considered for replacement.
3. Disinfection fogging. Chemgene HLD4H is fogged throughout the unit, with special attention to door tracks, cabinet edges, the lower walls, the bathroom and the inner side of the deck threshold.
4. Controlled-dose ozone treatment. The unit is sealed and the ozone generator runs for a period suited to the room size. During this time there must be no people, pets or plants inside. Sensitive electronics and artworks should be removed or covered.
5. Ventilation before re-entry. Windows and doors are opened and the AC is run in fan mode for the time our team specifies, until no ozone smell remains.
6. Re-check and aftercare advice. We check the odor and the risk points again and give advice on caring for the door track and controlling humidity in the long term.

Ozone safety: Ozone is a highly effective gas and must be used correctly. No people, pets or plants may be inside during treatment, and the space must be fully ventilated before anyone goes back in. For rubber parts and sensitive electronics, the team controls the dose and recommends removing or covering them before work begins.

Pool-Side Hot Spots That Need Extra Attention

Sliding door tracks and weep holes. This is where most hidden odor lives. If possible, have a technician lift the sliding panels out, wash the sediment from the track and the outer weep holes, then let everything dry before disinfection. If the weep holes stay blocked, the next heavy rain will pool in the track again and the smell will return.

Door seals and silicone. Rubber that has soaked in dirty water for days may have mold growing inside it. If you see black spots that will not wipe off, ask a technician to replace the seals or re-apply silicone once everything is dry. This also improves water-tightness for the next rainy season, which is a real bonus for a unit at pool level.

Timber or composite deck outside the door. If this is a common area or an area maintained by building management, coordinate with them first. Mud can remain trapped under the decking and keep sending odor into the unit, even after the inside is clean.

Curtains and upholstery. Fabric that touched muddy water should be taken down and washed hot according to the care label, or sent to a dry cleaner. Fabric that did not get wet but has absorbed the musty smell responds very well to ozone treatment.

Air conditioner and condensate drain. A pool-side unit that was closed for several days often has mold in the evaporator coil and the drain tray. Have the AC cleaned before or after ozone treatment, following our team's advice, so the unit does not blow the old smell back into the room.

The pool water itself. Treating pool water and the filtration system is the job of the pool maintenance company hired by the building. The WHD team works inside the unit and in areas we have been authorized to treat. Please check with management that the pool has been properly treated before you use it again.

10 Reasons Pool-Side Unit Owners Choose Disinfection Fogging and Ozone Treatment

1. Fine mist reaches door tracks and under cabinets, where hands and cloths cannot.
2. It uses CHEMGENE HLD4H, a disinfectant designed for surface disinfection in a wide range of settings.
3. Ozone treatment reduces the musty odor trapped in curtains, sofas and walls.
4. It helps reduce airborne mold spores, so the room feels easier to breathe in again.
5. Our team coordinates with building management, so access to the building goes smoothly.
6. Clear ozone safety procedures: nobody, and no pet, stays inside during treatment.
7. Your unit is ready to rent out or move back into sooner.
8. You get practical advice on what to remove, instead of guessing what to keep and what to throw away.
9. It combines well with our dust mite removal service for mattresses and sofas that did not sit in water.
10. Owners who want to keep up the care afterwards can use the CHEMGENE 750 ml spray to wipe tracks and door edges regularly.

Before and After: A Pool-Access Unit After the Water Recedes

What the Owner Said

"At first I thought the whole unit would have to be stripped and rebuilt. When the team came to look, they showed me that most of the smell was coming from the door track and from under the swollen floor. We removed only what was really necessary, then they did the fogging and the ozone treatment. After airing it out for the time they told me, the smell that used to come back every morning was much weaker. Now I can sit by the pool in the evening again."

Prae, owner of a pool-access unit in Bang Phli (story from the field)

Checklist for Owners and Tenants Before the Appointment

• Photograph the water line, floor, cabinets and door track. These photos are useful for your insurer and for discussions with building management.
• Let management know in advance when our team will enter the building, and book the service lift if needed.
• Take valuables, important documents and sensitive electronics out of the unit, or gather them in one spot to be covered.
• Remove indoor plants and plants on the deck, as well as all pets.
• If the unit is rented, tell your tenant when they will need to be out during ozone treatment and the ventilation period that follows.
• Note how high the water came, how many days it stayed, and what has already been done. This helps our team plan exactly where to focus.

Owners who live abroad or in another province often ask whether they need to be present. In many cases a trusted relative, the tenant, or the building's management office can let the team in, as long as everyone agrees on the schedule beforehand and the unit has been prepared according to this checklist.

Living by the Pool After the Flood: Habits That Keep the Smell Away

A pool-side lifestyle is wonderful, but it does mean living with more humidity than most condo owners. A few simple habits make a big difference once your unit has been restored.

• Clear the weep holes monthly. A small brush or a piece of wire is enough to keep them open. Blocked weep holes are the number one reason water sits in the track.
• Dry the track after heavy rain. A quick wipe with a dry cloth takes a minute and stops slime from forming.
• Use a dehumidifier when the unit is closed. If you travel or the unit sits empty between tenants, a dehumidifier with a drain hose keeps humidity under control.
• Keep furniture a few centimeters from the walls. Air needs to move behind sofas and wardrobes, or condensation will build up there.
• Service the AC on schedule. Pool-side units benefit from more frequent AC cleaning than units higher up.
• Watch the lower edges of built-ins. Black spots usually appear there first. Deal with them early before they spread.

Frequently Asked Questions

1. My unit is on an upper floor and the water never reached it, but it smells musty. Do I need treatment too?
Upper units that were closed for several days during the storm can still build up humidity and develop mold inside the air conditioner. If the smell persists after airing the unit out and cleaning the AC, ozone treatment alone may be enough, depending on the on-site assessment.

2. Should I wait for management to clean the pool and deck first?
Ideally, yes, or at least wait until the mud around your door has been washed away. Otherwise, when you open the door to ventilate, sediment and odor from outside will simply come back in.

3. My laminate floor has swollen. Can it be kept if it is disinfected?
A buckled floor usually has water trapped underneath. Fogging from above will not dry what is below the planks, so we recommend having a contractor remove it, letting the concrete slab dry, and disinfecting before laying a new floor.

4. Will ozone damage the rubber seals on my glass door?
Some rubber and certain materials can degrade if exposed to high-concentration ozone for too long, which is why our team controls the dose and duration. Seals that are already damaged from soaking should be replaced once everything is dry.

5. How long will my tenant need to stay out?
It depends on the size of the unit and the severity of the problem. Our team will give clear treatment and ventilation times on the day, and the tenant should plan to be out for that whole period.

6. After the service, how do I stop the smell from coming back?
Check the weep holes in the door track monthly, dry the track after rain, use a dehumidifier when the unit is closed for long periods, service the AC on schedule, and watch for black spots along cabinet edges. Deal with them as soon as you see them.

7. Building management wants to treat the common areas around the pool too. Is that possible?
Yes. Management can contact our team to assess a disinfection service for changing rooms, restrooms and walkways around the pool. The pool water itself should be treated by the pool maintenance provider to the proper standard.

Ready to Enjoy Your Pool-Side Unit Again?

Let the World Health Disinfection team survey your unit and plan disinfection fogging and ozone treatment that fits your space.

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 source: WHO: Floods and health and Thailand Department of Disease Control