The short version: every health and wellness business sells the same thing: the feeling of being clean, refreshed and safe. Customers walk barefoot, lie face-down on massage mats, share towels, grip dumbbells the last person just put down, and sit in hot, humid steam rooms. When a flood gets into the premises, every one of those touchpoints becomes home to mould, bacteria and musty odour. Reopen too soon without disinfecting thoroughly, and the risk is not only customers picking up athlete's foot or a rash. It is the reviews that can undo years of reputation. This guide walks owners through recovery step by step and explains how the WHD Building Ozone Disinfection service closes out the work before the doors open.

A typical scenario: a massage shop by the Ping River in Chiang Mai

Prae runs a ten-bed Thai massage and foot spa in a shophouse near the Ping River in central Chiang Mai. Most of her customers are tourists who find her through online reviews, and her ratings are high because of the cleanliness, the soft lemongrass scent at the door, and the crisp white sheets changed for every guest.

The year the Ping overflowed into the city, brown muddy water came into the shop almost waist-high and stayed for about five days. Prae got the towels and massage oils upstairs in time, but the ten floor mattresses, the foot-bath chairs, the wooden tubs, the towel warmer and the small herbal steam room at the back were all submerged.

When the water went down, she and her staff shovelled out the mud, hosed the floor, dried the mattresses in the sun out front, and lit incense and aroma burners in every corner. After a week the shop looked clean enough, so she reopened, because rent and wages were still due. Within two weeks one customer wrote that the rooms smelled like a basement. Another messaged to say she had an itchy rash around her ankles after a foot soak. Two therapists started getting itchy between their toes. When Prae flipped a mattress over, she found its underside speckled with small black spots.

Prae did nothing wrong on purpose. She did everything she thought was needed, but the order and methods were incomplete. The same thing happens to gyms in Nonthaburi, yoga studios in Pathum Thani, massage shops in Ayutthaya and spas in Hat Yai after every flood. Businesses that sell cleanliness take a double hit: the water damage, and the damage to customer trust.

Why gyms, spas and massage shops are at higher risk than ordinary buildings

They are full of absorbent materials. Massage mattresses, foam padding on machines, yoga mats, rubber gym flooring, privacy curtains between beds and carpets all soak water deep inside. The surface may dry within days, but the core stays damp for a long time and supports mould and bacteria.

Humidity is part of the service. Steam rooms, saunas, foot baths, whirlpools, showers and locker rooms are humid even on a normal day. Add floodwater, and humidity in the building stays above normal for weeks.

Direct skin contact and bare feet. Customers and staff touch floors, pads and equipment with bare skin, and many have small abrasions from training or shaving that give germs a way in.

Complex water systems. Whirlpools, recirculating foot baths, water heaters and storage tanks can take in backflow from the flood and harbour the slimy biofilm that germs love.

High turnover of shared linen. A busy massage shop or spa goes through piles of towels, sheets, sarongs and robes every day. If the laundry room, towel warmer or linen cupboard was flooded, clean items can pick up mould spores and musty odour the moment they are folded and stored. Customers notice a damp-smelling towel instantly, and because it touches the face and body, it shapes their whole impression of the visit. Gyms face the same issue with rented towels and shared yoga props, which is why linen storage deserves as much attention as the treatment rooms themselves.

The germs hiding in the premises after the water recedes

1) Skin fungi: athlete's foot and ringworm

Dermatophyte fungi love wet floors, shower areas, locker rooms and damp mats. They spread through bare feet and shared towels. Symptoms are itching between the toes, scaly peeling skin, and red rings with a clear edge on the body or groin. During floods, feet that stay wet for long periods soften and become much easier to infect.

2) Staphylococcus on equipment and pads

Staphylococcus aureus lives on many people's skin, but entering a cut it can cause boils, pustules and skin inflammation. Gyms and sports facilities have reported outbreaks of skin infections linked to shared mats and equipment, and some drug-resistant strains are harder to treat. Torn foam pads that stay damp help the bacteria survive longer.

3) Pseudomonas in warm tubs and foot baths

Pseudomonas thrives in warm water and forms biofilm in pipework. It can cause itchy red bumps around hair follicles after soaking in a poorly maintained hot tub, as well as ear and wound infections. Foot baths and whirlpools whose pipes took in floodwater need their plumbing specifically flushed and disinfected.

4) Legionella in hot-water systems and spray

Legionella grows well in warm, stagnant water in pipes, tanks and whirlpools. People are infected by breathing contaminated water droplets, and it can cause severe pneumonia in older adults, smokers and people with chronic illness. Water systems left idle for days during a flood should be flushed and checked before use.

5) Mould in steam rooms, saunas and walls

Timber walls, tile grout, ceilings and air-conditioning vents in spa rooms grow black mould quickly after a flood. Airborne spores make allergic customers sneeze and can trigger asthma. The musty smell of mould is what customers notice before they see anything.

6) Plantar warts and viruses on surfaces

The virus behind plantar warts likes wet surfaces around pools and showers, while viruses causing stomach and respiratory illness can sit on handles, armrests and machine buttons.

Who is most at risk

• Older customers coming for physiotherapy-style massage or warm soaks, whose immunity is lower.
• Pregnant women using prenatal massage or yoga.
• Children in swimming or gymnastics classes.
• People with diabetes, whose foot wounds heal slowly and infect easily.
• Staff, who spend all day in humid areas and are first in to clean after the flood.

What reopening too early does to the business

Customer and staff health: rashes, fungal feet, pustules and allergy symptoms after a visit may seem minor to an owner, but to a customer they are a reason never to return. Staff who fall ill need time off, leaving the business short-handed just when it needs everyone.

Revenue: while closed, there is no income but rent and wages keep running, so owners want to reopen as fast as possible. Yet reopening and then having to close again over smell or mould costs far more than waiting a few extra days to finish properly. Gym members who cancel, and regular massage clients who move to another shop, are very hard to win back.

Online reputation: spas and massage shops live on map listings and travel platforms. A few reviews mentioning a musty smell or damp-smelling towels pull the average down and stay on the listing for a long time. A gym named in a neighbourhood social-media group as the place someone caught a fungal infection loses the trust of the whole community.

Time and labour: cleaning again and again because the smell will not leave, ripping out mouldy mattresses after reopening, or shutting the steam room because of black mould wears owners and staff down.

Your team and their families: therapists and trainers are often their family's main earners. If the business cannot reopen, or has to close again, their income vanishes too. The stability of one shop supports several households.

Why the methods many businesses use are not enough

1. Incense, aroma burners or lemongrass spray. Scent is part of a spa's identity, but used to cover mustiness it creates an odd blend that customers immediately sense is wrong, and fragrance does nothing at all to spores or bacteria.

2. Sun-drying mattresses and pads out front. Sun dries the outer layer, but a foam or kapok core that soaked up muddy floodwater is very hard to dry and may hold contamination deep inside. Most mattresses and pads that sat in floodwater for long should be thrown away, not returned to service.

3. Wiping only the handles with alcohol. Alcohol works on smooth surfaces, but it does not reach joints, the underside of seats, the seams between rubber floor tiles or the vents of a treadmill, where mud and moisture still linger.

4. Switching the air-conditioning straight back on. If coils and ducts have not been cleaned, the system will blow spores and musty air around the whole premises instead of helping.

5. Repainting or laying new flooring over the top. If the wall or slab underneath is still damp, mould grows beneath the new paint or floor within weeks and has to be ripped out again.

6. Adding chlorine to the foot bath and carrying on. Dosing fresh water does not clean biofilm inside recirculation pipes that took in floodwater. The system must be flushed and disinfected according to the manufacturer's or a specialist technician's instructions.

How WHD ozone treatment gets the premises ready to reopen

The right sequence is the heart of a confident reopening. Ozone treatment does not replace removing mud, discarding soaked pads and mattresses, washing surfaces, flushing water and air-conditioning systems, or drying the building. It is the finishing step after those jobs are done, dealing with the germs and odour still left in the air and in every corner before the first customer walks in.

Ozone (O3) is a strongly oxidising gas. Released into a closed space, it spreads through treatment rooms, steam rooms, locker rooms and the gym floor, into the seams of rubber flooring, under machines, behind lockers and into curtain fabric. It breaks down the cell structures of mould, bacteria and viruses and splits the molecules behind mustiness and sweat odour. It then reverts to oxygen (O2), leaving no chemical residue on the massage beds and equipment that customers' skin touches. According to test results certified for the company by Thailand's Department of Medical Sciences and Intertek (UK), the WHD process eliminates 99.99% of viruses, bacteria and mould.

The process for gyms, spas and massage shops

1. Survey and zone planning. The team walks every area, including treatment rooms, steam room, locker rooms, laundry and storage, checks that washing and drying are complete, and orders the zones around your reopening plan.
2. Preparation. Staff, customers, pets and decorative plants leave the area. Lockers, linen cupboards and drawers are opened; doors, windows and air-conditioning are shut. For equipment with rubber components or high-value items, the team will advise on placement or removal.
3. Ozone release. Typically about 30 minutes per zone, with concentration set to the size of each room.
4. Contact time. The gas works in the sealed, unoccupied space.
5. Rest and ventilation. Doors and windows are opened so ozone reverts to oxygen. Nobody re-enters until the time the team specifies.
6. Odour check and handover. The team walks through with the owner and advises on humidity control and cleaning routines after reopening. Jobs of 15,000 baht or more receive a free medical-grade disinfectant spray to use in the shop straight away.

Safety first: ozone treatment is carried out only in an empty, closed space. No staff, customers, pets or plants may be present during treatment, and re-entry is allowed only after the rest and ventilation period the team gives you. Book it outside opening hours or the day before reopening.

10 reasons gyms, spas and massage shops should ozone-treat before reopening

1. Customers smell before they see. Removing mustiness at its source restores the first impression without relying on perfume to hide it.
2. It reaches rubber-floor seams and the space under machines, where a mop cannot go but bare feet tread every day.
3. It covers the dampest rooms: steam rooms, locker rooms and showers, the main sources of skin fungi.
4. No chemical residue on skin-contact surfaces, ideal for massage beds and equipment pads. Read more on ozone and chemical residue.
5. Several germ types in one pass: mould, bacteria and viruses across every zone.
6. It reduces odour in curtains and pads that are still usable, so you do not have to throw away items in good condition.
7. It is quick and can be booked after hours: about 30 minutes per zone plus ventilation, with no impact on your reopening day.
8. There is certification to point to, based on test results certified for the company by the Department of Medical Sciences and Intertek. See the certificates.
9. You can tell customers with confidence that the whole premises was disinfected before reopening, which helps win trust back. Details on the ozone disinfection service page.
10. The team understands service businesses, planning zones around your reopening schedule and advising on ongoing care. Contact WHD.

Example case: a mid-sized gym in Pak Kret, Nonthaburi

This example case is an illustrative scenario based on the kind of job that comes up often, to show how the work is sequenced.

Ton owns a mid-sized gym in Pak Kret with several hundred regular members, mostly office workers and older residents from nearby housing estates. It occupies the ground floor of a commercial building, with a weights area, cardio zone, yoga studio, men's and women's locker rooms and a small sauna. About thirty centimetres of water stood inside for four days.

What Ton got right from the start was not rushing. His team lifted every rubber floor tile to wash and dry individually, threw out soaked yoga mats and foam pads, had every air-conditioner cleaned, had the treadmills' electrics checked, and brought in a plumber to flush the storage tank and the shower hot-water system. Then they ran dehumidifiers for several days.

Even so, the locker rooms and sauna still smelled musty, and Ton worried about fungal foot infections because many members are older or have diabetes. He contacted WHD. The team scheduled ozone treatment after closing on the night before reopening, in five zones, with every locker open and the ventilation shut during treatment. The next morning, after the rest and ventilation period, the team walked through with Ton before he unlocked the doors.

Ton posted in the members' group that the gym had been washed, re-padded, had its water system flushed and had been ozone-disinfected throughout before reopening, and asked everyone to wear sandals in the showers. Most members were back to their usual routine within the first week. The lesson: being transparent about what you did is worth as much as the cleaning itself.

Reopening checklist: before and after ozone

Keep your team safe during clean-up

• Boots, rubber gloves and masks on, and every cut covered before starting.
• Cut power to flooded zones and have an electrician check before using machines or water heaters.
• Any staff member with fever, calf pain, red eyes or diarrhoea after wading must see a doctor and mention the floodwater, as it could be leptospirosis or a gut infection.

Finish before ozone

• Remove mud and wash floors, walls and all rubber-floor seams.
• Discard massage mattresses, foam pads, yoga mats and carpets that sat in floodwater.
• Hot-wash towels, sheets and customer robes, or discard heavily contaminated items.
• Throw away opened massage oils, creams and herbs that touched floodwater.
• Have air-conditioning, ducts, hot-water systems, whirlpools and recirculating foot baths cleaned by technicians.
• Run dehumidifiers until walls and floors are completely dry.

On ozone day

• Book outside opening hours; everyone, pets and decorative plants out.
• Open all lockers, linen cupboards and drawers; tell the team about expensive equipment or rubber parts.

After ozone and after reopening

• Re-enter only after the rest and ventilation period the team specifies.
• Set a routine to wipe down equipment and massage beds after every customer.
• Ask customers to wear sandals in showers and give everyone their own towel.
• Control humidity in steam and locker rooms, and ventilate after closing each day.
• Tell customers openly what recovery steps the business has taken.

Frequently asked questions

After ozone, do we still need to throw out flooded massage mattresses?
Yes. Mattresses and foam pads that sat in floodwater hold mud and contamination inside. Ozone comes after cleaning and discarding; it does not replace damaged materials.

Will ozone disinfect the pipes of a whirlpool or foot bath?
Room ozone treats the air and surfaces in the room, but it does not clean biofilm inside water pipes. Water systems must be flushed and disinfected separately according to the manufacturer's or a specialist's instructions.

How long must we close on treatment day?
About 30 minutes per zone plus ventilation. Most businesses book after closing or the day before reopening, and the team gives a clear re-entry time. Nobody, and no pets, may be inside during treatment.

Can ozone damage gym machines or leather upholstery?
The team controls concentration and time for each space. For equipment with rubber parts, expensive leather or specialist electronics, tell the team in advance so you can plan placement together.

Will ozone remove our signature aroma too?
Lingering scent in the air will be reduced, which is a good thing: when you reopen, your signature scent starts on clean air instead of mixing with mustiness.

A customer has a rash, or staff have itchy feet. What should we do?
Recommend they see a doctor for proper diagnosis and treatment, and check the high-risk spots in the premises. Ozone reduces germs in the environment but is not a medical treatment.

Ready to reopen with confidence? Let WHD disinfect the whole premises first

Free consultation and site assessment, with zones planned around your reopening schedule, for gyms, spas, massage shops, yoga studios and beauty clinics.

Book Pre-Opening Ozone Treatment

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

Related reading

• Residential and Building Ozone Disinfection
• Disinfection services for businesses
• Chemgene surface disinfectant
• Contact WHD

References

• CDC: Floods on cleaning buildings and managing mould after flooding
• Department of Disease Control, Thailand on flood-related diseases such as leptospirosis and skin infections