A Story from the Field: Two Quotes That Made No Sense Side by Side

Khun Pimlada is a mother of two who lives in a three-storey townhome in a soi off Lat Phrao 101, Bangkok. During the 2026 floods, water about half a metre deep sat on her ground floor for four days. The living room, with its fabric sofa, wooden bookcase and laminate floor, took the worst of it. Two weeks after the water drained, black spots began to appear on the downstairs walls, a musty smell drifted up the open staircase to the children's bedrooms on the second floor, and her youngest started sneezing every morning.

She called two service providers. The first gave her a figure over the phone almost immediately, without asking many questions. The second asked for photos, wanted to know how high the water had risen and what the walls were made of, and arranged a site visit before quoting. The two quotations were noticeably different. Khun Pimlada could not understand why the "same job" would be priced so differently, and she worried that if she chose the cheaper one and the work had to be repeated, she would end up paying more.

"I don't need the cheapest option," she told our team. "I just want to understand what I am paying for." It is a completely reasonable request, and one we hear all the time from homeowners in Lat Phrao, Chokchai 4, Wang Hin and Chantharakasem after a flood.

This article deliberately does not quote prices, because an accurate price depends on what is actually found on site. Instead, it explains the factors that determine the cost of disinfection fogging and ozone treatment, so that you can read a quotation with confidence and compare offers fairly.

Why Choosing on Price Alone Is Risky

• Health risk. If the work misses hidden mold, for example behind cabinets or under laminate flooring, spores keep circulating. Children and anyone with allergies continue to suffer symptoms.
• Paying twice. Incomplete work has to be redone, or walls and furniture need extra repairs as mold spreads.
• Lost time. The family keeps living with the smell, or has to stay elsewhere longer than necessary.
• Lack of clarity. A quotation that does not define the scope of work makes it impossible to check whether you received the full service.

Many homes in Lat Phrao are multi-storey townhomes or townhouses with an open staircase connecting every floor. Musty air and mold spores from the ground floor easily rise into upstairs bedrooms. A job that only treats the rooms where damage is visible, without considering how air moves through the whole house, may not solve the problem. That is why a site survey before pricing matters so much.

On the health side, flood-borne germs such as diarrhoea-causing bacteria, the leptospirosis risk from leftover mud, and mold that aggravates allergies and asthma are not things to economise on too aggressively.

The Eight Main Factors That Affect the Price

1. Floor area and number of rooms

Usable area, number of floors, number of rooms and ceiling height all affect how much disinfectant is needed, how long the fogging takes, and how many ozone treatment cycles are required. A house divided into many small rooms may need to be ozone-treated zone by zone.

2. How badly the water affected the property

How high the water rose, how many days it sat, and whether it came from overflowing drains or was mostly rainwater all indicate the level of contamination. A house that sat in sewage-contaminated water for days usually needs more thorough work than one where water came in for a few hours.

3. How much mold there is, and where

A few small spots on a tiled wall are very different from a large patch spreading behind a built-in wardrobe, under laminate or above a ceiling. Hard-to-reach locations take more time and preparation.

4. Materials in the home

Plaster, gypsum board, timber, laminate, carpets and upholstered furniture absorb moisture and odours differently. Homes with a lot of porous material often need longer ozone treatment to deal with deeply embedded smells.

5. Strength of the odour

A faint, newly developing damp smell and a sewer-and-mildew odour that has soaked into curtains, sofas and mattresses for weeks require different ozone doses and treatment times.

6. The scope of service you choose

Disinfection fogging only, ozone treatment only, or both, plus any add-ons such as dust mite removal for mattresses and sofas or mosquito spraying around the property, all affect the total.

7. Site access and preparation

Narrow sois, parking, carrying equipment upstairs, and covering or moving electronics, artworks and rubber items are all preparation tasks that take time.

8. Timing and urgency

Demand is very high straight after the water recedes. Requests for specific time slots, such as outside normal working hours or a deadline before a shop reopens, can affect how the work is scheduled.

Disinfection Fogging vs Ozone Treatment: Why They Are Priced Separately

Disinfection fogging targets germs on surfaces: floors, walls, skirting, stair rails and high-touch points. It uses a disinfectant and a fine-mist fogger, and the technician has to work through every room. The workload therefore scales with floor area and the number of surfaces.

Ozone treatment targets airborne mold spores and odours embedded in materials. A generator runs in a sealed room, followed by a ventilation period. The workload scales with room volume, odour strength and the number of zones that must be treated separately.

In both cases, the product and equipment are only part of the cost. Much of the value lies in the technician's time on site: surveying, preparing rooms, covering sensitive items, running the treatment carefully, managing ventilation and re-checking. That is also why two quotes that look similar on paper can deliver very different results; the difference is often in how thoroughly the preparation and follow-up are done.

The two services complement each other. Homes with both sewage contamination and strong musty odours usually get the best result from doing both. If odour is the main issue, it may make sense to start with ozone treatment. Our team will recommend what fits your budget and the condition of the house.

The Hidden Costs of Waiting Too Long

Many households decide to wait and see because they are worried about cost. Waiting has costs of its own, though they are less visible. Mold spreads from walls into built-in cabinets and wooden door frames, increasing what must be removed and repaired. Mattresses and sofas that could have been saved become write-offs. There are medical bills when family members' allergies or asthma flare up, and days of work lost. Acting early, before the problem spreads, is usually better value. Even if you are not ready to book, getting a survey and a written scope early gives you the information to plan and budget properly.

What a Good Quotation Should Spell Out

• Which areas and rooms are included, clearly listed by floor.
• The method: ULV disinfection fogging, ozone treatment, or both.
• The name of the product used, for example CHEMGENE HLD4H.
• Safety steps: how equipment is covered or moved, and how long ventilation takes before you can return.
• What you need to prepare before the appointment.
• What is not included, such as cutting out gypsum walls, repainting or removing bulky waste.
• Whether there is a follow-up check, and how to contact the team if there is a problem.

If two quotations describe different scopes of work, their totals cannot be compared directly. Asking clear questions at the start makes the decision much easier.

How to Prepare Information for an Accurate Quote

1. Photograph each room, showing the water line on the walls and any visible mold.
2. Estimate the floor area, number of floors and number of rooms you want treated.
3. Note how high the water rose, how many days it stayed, and whether it came from drains or rain.
4. List wall and floor materials, such as plaster, gypsum, laminate or timber.
5. Tell us whether there are older people, young children, patients or pets in the home.
6. Say whether the mud has already been cleaned out, and which products you have used.
7. Give us the dates and times that suit you for the work.

You can send all of this via LINE @whd268. Our team will make a preliminary assessment and arrange a site survey to confirm the scope before issuing a quotation.

Questions to Ask When Comparing Two Offers

When Khun Pimlada laid her two quotations side by side, the most useful thing she did was ask each provider the same short list of questions. You can do the same:

• Did you see the property, or is this an estimate from a phone call? A price given without a survey is a guess, and the final figure may change on the day.
• Exactly which rooms and floors are included? If one quote covers only the ground floor and the other includes the staircase and bedrooms above, the totals are not comparable.
• Which product will you use, and how is it applied? A named product and a clear method, such as ULV fogging, tell you what you are buying.
• Is ozone treatment included, and how many zones? One generator run in a large open-plan space is not the same as treating several closed rooms one after another.
• How will you protect my electronics and furniture? Covering or moving sensitive items should be part of the plan, not an afterthought.
• When can my family return? The answer should include ventilation time.
• What happens if the smell comes back in one area? A follow-up check shows confidence in the work.

It is also worth asking how long the provider expects the job to take on site. A whole-house treatment that includes preparation, fogging, ozone and ventilation rarely fits into a very short visit, so an unusually quick estimate may mean some steps are being skipped.

The cheaper quote is not automatically the worse one, and the more expensive quote is not automatically better. What matters is whether the scope matches the real problem in your home.

A Worked Example: How the Factors Combined in One Lat Phrao Townhome

To make the factors more concrete, here is how they played out in Khun Pimlada's home, without the numbers. During the survey, our team noted that water had sat for four days and had come partly from overflowing drains, which meant a higher level of contamination than rain alone. The ground floor had plastered walls but also a gypsum partition under the stairs and a laminate floor throughout the living room. Mold was visible on two walls and, once the bookcase was moved, behind it as well. The musty smell was strongest downstairs but clearly noticeable on the second floor because of the open staircase.

Putting that together, the recommended scope was: disinfection fogging of the entire ground floor and the staircase; ozone treatment of the ground floor in two zones, because the kitchen could be closed off separately; and a shorter ozone treatment on the second floor landing and children's bedrooms. The gypsum panel under the stairs was flagged as something to cut out and replace after treatment, and that was listed as not included. Because the family had already removed the sofa and rinsed out the mud, preparation on the day was straightforward.

The phone-only quote she had received earlier had assumed "one floor, one treatment". Neither quote was dishonest. They simply described different jobs. Once she could see the scope written down, the difference made sense.

Ways to Keep the Cost Reasonable Without Cutting Corners

• Do the mud and removal work yourself, safely. Wearing boots, gloves and a mask, shovel out wet mud and remove ruined items before the appointment.
• Book early. Treating the house before mold spreads into cabinets and door frames keeps the scope smaller.
• Prepare the rooms. Pull furniture away from the walls, open wardrobes and move small electronics to a safe place, so the team spends its time treating rather than moving things.
• Share good photos and details. The more accurate the information, the more accurate the preliminary assessment.
• Combine services in one visit. If you also need dust mite removal or mosquito spraying, planning them together can be more efficient than separate visits.
• Look after the result. Keeping humidity down afterwards with ventilation and a dehumidifier protects your investment and reduces the chance of needing a repeat visit.

Why DIY Savings Can Cost More in the Long Run

• Buying bleach and pouring it everywhere. It does not reach hidden mold, and it risks irritation and damage to belongings.
• Running fans and air conditioning all day. The electricity bill climbs while moisture stays inside the walls.
• Air freshener sprays. They mask the smell temporarily, so you keep buying more.
• Painting over moldy walls. Mold returns within weeks and you pay for painting a second time.

Doing some of the work yourself is sensible. Shovelling out mud, removing ruined mattresses and carpets, and rinsing surfaces with clean water all reduce the professional workload and can make the service more efficient. The aim is not to avoid DIY entirely, but to make sure the parts that need equipment and experience, such as whole-house fogging and controlled ozone treatment, are done properly.

WHD's Service: A Clear, Verifiable Process

1. Site survey. We assess the area, the damage and where mold is growing.
2. Cleanup and removal advice. We tell you what to do before the appointment so the work is effective and no time is wasted.
3. Disinfection fogging with CHEMGENE HLD4H. ULV mist covers floors, walls, the backs of cabinets and the undersides of furniture.
4. Ozone shock treatment. The area is sealed; sensitive electronics, artworks and rubber items are covered or removed; and the ozone dose is controlled for the room size.
5. Ventilation. Doors and windows are opened until the ozone has broken down before you return.
6. Re-check. We check odours and risk points and give you advice on managing humidity.

Ozone safety: no people, pets or plants may be inside during treatment, and the space must always be ventilated before anyone goes back in.

10 Reasons a WHD Quotation Makes the Decision Easier

1. We survey first instead of guessing a price.
2. The scope is explicit: which rooms, and which method.
3. The product is named: CHEMGENE HLD4H.
4. You choose disinfection fogging, ozone treatment or both.
5. You know in advance what to prepare.
6. Safety steps and ventilation times are clearly stated.
7. Electronics are covered or moved and the ozone dose is controlled.
8. Exclusions are stated honestly.
9. A follow-up check is part of the service.
10. You can ask questions by phone or LINE, and read more about residential ozone disinfection.

Customer Voice

"What I liked was that the WHD team looked at the house first and explained which rooms needed fogging and ozone, and why. The quotation said clearly what was and was not included, so I could decide with peace of mind. After the work, the house smelled much better."

— Khun Pimlada, townhome off Lat Phrao 101 (a story from the field)

Frequently Asked Questions

Q: Why doesn't this article give prices?
A: Because the price depends on each home's area, damage and scope of work. A figure given without seeing the property could be misleading. Contact our team for a quotation that matches your home.

Q: Can you give a preliminary estimate from photos?
A: Yes. Send photos and basic details via LINE @whd268. We will make a preliminary assessment and arrange a survey to confirm the scope.

Q: Can you treat only the ground floor?
A: Yes. However, if the musty smell has already reached the upper floors, we may recommend ozone treatment upstairs as well for a complete result.

Q: Do I need both disinfection fogging and ozone treatment?
A: It depends on the house. Homes where water sat for days and the odour is strong usually benefit most from both. We will advise based on what we find.

Q: How long do we need to leave the house during ozone treatment?
A: It depends on the size of the area; we will tell you before we start. No people, pets or plants may be inside, and the space is ventilated before you return.

Q: Will the price change on the day?
A: Once the survey has confirmed the scope, the quotation reflects that scope. If something new is discovered, such as hidden mold behind a wall that needs extra work, we will explain it and agree any change with you before proceeding.

Q: Do you serve Lat Phrao and Chokchai 4?
A: Call 065-556-6294 or LINE @whd268 to check availability and arrange a survey.

Get a Quotation That Matches Your Home

Send us photos and basic details. The WHD team is ready to survey homes in Lat Phrao and nearby areas, explain the scope in plain language, and give you a written quotation you can compare with confidence.

See Our Disinfection Service – Click Here

Book Ozone Treatment – Click Here

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

Related Services and Reading

• Residential ozone disinfection
• Ozone treatment for odours and chemical residue
• Dust mite removal service
• All articles
• External sources: WHO fact sheet: Floods and Department of Disease Control, Thailand