The SC CL-100 covers moisture and wood-decay fungi, not mold. A musty AC smell will not fail your CL-100, but it can spook a buyer and stall an FHA or VA appraisal on visible mold. Whole-home disinfection for mold before you list is $0.30 per heated square foot ($200 minimum), vents $50 each on the same visit or from $399 alone, with a transferable 12-month written guarantee.
See your price
- Whole-home disinfection: $0.30 per heated sq ft ($200 minimum)
- Clean the vents on the same visit: $50 each (no extra minimum)
- Both include Bactronizing with BactroKill Plus + 12-month written guarantee
Not sure what you need?
Start with the vents
A smell that rides the air is growing in the duct work. We scrub each vent and return with a rotary brush, clean the registers, the coil and the outside of the air handler, then treat them. $50 a vent, from $399 on its own. Spores travel on the air, so most people add the whole-home disinfection on the same visit, and then the vents carry no minimum. 12-month written guarantee.
Start with the whole home
A smell that sits in the rooms, or came with the last people, is on the surfaces, not only in the air. Whole-home disinfection sprays every surface in the house, closets included, plus the duct work and the drain pan: $0.30 per heated square foot, $200 minimum, about 30 to 75 minutes, and you can stay home. Dust or growth in the vents needs cleaning first, so add the air duct cleaning at $50 each on the same visit if the vents are dirty. 12-month written guarantee.
We look first
Mold you can see gets wiped off, not sprayed over. Every one is different, so we look before we price it, and Greg puts the price in writing before any work starts.
Fix the water first
Mold is a water problem first. Wet material grows again, so the leak, the flood or the drain line gets fixed before anything is sprayed. Once it is dry we treat it, and if something is still wet we say so before we start.
Two ways to be sure
If you can smell it or see it, the CDC says you do not need to know the type, so most people skip the test and treat. To be sure anyway: while we are at the house we can swab a surface and read it on a hand-held meter, or send samples to a lab, $350 for two and $450 for four.
Request a window Or start with the treatment Call 843-282-7777
Open now. Closes at 4 pm.
Call 843-282-7777Request a windowGreg confirms it in writing.Do not know the square footage? Request a visit without a number. We work it out when we come out.
Veteran owned. Licensed and insured. EPA-registered product. 12-month written guarantee.
If you are listing a home in Summerville, Cane Bay, Nexton, Carnes Crossroads, Goose Creek, or Moncks Corner, the air system is one thing you can clear off the table before showings start.
What is a CL-100 inspection, and when is it required in SC?
A CL-100 is South Carolina’s wood-infestation report. A licensed inspector checks the structure for wood-destroying organisms, like termites and wood-decay fungi, plus excessive moisture conditions. FHA and VA lenders commonly require it before closing. It is a moisture and structural letter, not a mold test.
The CL-100 (officially the SC Wood Infestation Report) is filled out by a licensed pest-control inspector. It reports two things: evidence of wood-destroying organisms, which includes termites and wood-decay fungi, and any “excessive moisture condition” in the substructure. That second phrase is defined in South Carolina Regulation 27-1085, the standard Clemson enforces, and South Carolina REALTORS publishes the text (source). Many South Carolina buyers, and most FHA and VA lenders, require a clear CL-100 before the loan funds.
The part sellers miss: the CL-100 is about moisture and wood, not a clean bill of health for your air. Read the next section before you assume a clear CL-100 means your ducts are fine.
Does the CL-100 actually test for mold?
No. The CL-100 covers moisture and wood-decay fungi, not mold in your air ducts. An inspector can flag the high moisture that lets mold grow, but the report does not test for or certify mold. Treating your HVAC is complementary to the CL-100, not a way to pass it.
This is the single most misunderstood thing about selling a house in South Carolina. Wood-decay fungi attack the wood structure of the home. Mold growing on a cooling coil or inside ductwork is a different organism in a different place, and the CL-100 form does not test for it (Locke Key Associates; Lauren Zurilla & Associates).
A treatment does not make you “pass your CL-100.” Those are two different things. What is true: the CL-100 flags the moisture conditions that feed mold, and humid Lowcountry air is exactly that condition. A pre-listing treatment handles the mold the CL-100 leaves untouched, alongside the moisture work the CL-100 actually grades. The two jobs sit side by side. They do not substitute for each other.
What moisture readings count as an “excessive moisture condition”?
SC rules treat wood moisture at or above 20 percent, or standing water in the crawlspace or around the foundation, as an excessive moisture condition the CL-100 can flag. That moisture is also what feeds mold in your ducts, which is why moisture and the air system are worth handling together before you list.
The rule is specific. Excessive moisture conditions are present any time wood moisture content readings reach or exceed 20 percent, or standing water is present in the crawlspace or around the foundation, and wood-decay fungi become active at wood moisture levels of 28 percent and above (source). Confirm the reading and the remedy with your CL-100 inspector, since the call is theirs to make on the day.
Here is the link homeowners miss. The same humid air that drives a substructure moisture flag is the air your HVAC pulls across a cold coil and pushes through the ducts. The EPA puts it plainly: “the key to mold control is moisture control,” and it recommends keeping indoor humidity below 60 percent, ideally 30 to 50 percent (EPA, A Brief Guide to Mold, Moisture and Your Home). Fix the moisture story, and you take pressure off both the CL-100 and your air system.
Can a musty AC smell scare off a buyer at a showing?
Yes. A musty smell when the AC turns on is the first thing many buyers notice walking in, and it reads as a hidden problem. It will not fail a CL-100, but it can cost you offers and stall an FHA or VA appraisal if visible mold is present. Treating the source removes the smell.
Buyers form an impression in the first thirty seconds, and smell is part of it. A musty, mildew-like smell when the air conditioner runs signals “moisture problem” to a buyer before they have seen the kitchen. You can mask it with a plug-in for one showing, but it comes back the moment the air comes on, and a sharp buyer’s agent will catch it.
There is also a financing angle. FHA and VA appraisers can call out visible mold and require it to be addressed before the loan closes, which can stall or re-open a deal that looked done (confirmed against FHA/VA appraisal practice). Clearing the air system before you list keeps that off the appraiser’s report. If you want the full diagnostic on the smell itself, read why does my AC smell musty.
Should I treat before listing, and what does it cost?
If the house smells musty or you have seen growth around vents, yes. And the price comes off the same sheet the buyer will read.
Whole-home disinfection is $0.30 per heated square foot. Your heated square feet is already on your listing and your tax record, so you can price the job from your desk. Air duct cleaning and treatment goes on the same visit and covers the registers, the duct work, the coil and the outside of the air handler.
Pre-listing pricing, Greg’s prices vs national estimates
| Service | Price |
|---|---|
| Whole-home disinfection | $0.30 per heated square foot, $200 minimum |
| HVAC vents, on the same visit | $50 a vent, however many you have |
| HVAC vents, booked on their own | $50 a vent, starting at $399 |
| Dryer vent, added to the same visit | $50 ($99 when booked on its own) |
| Conventional HVAC-system mold removal | $2,000 to $10,000 (national estimate, Charleston SC area: HomeGuide 2026, This Old House 2026) |
| Structural mold remediation | $1,200 to $3,750+ (national estimate, Charleston SC area) |
The pre-listing math is simple. The $2,000 to $10,000 figure is conventional mold removal inside an HVAC system, and the $1,200 to $3,750+ figure is structural remediation, both national estimates for the Charleston SC area (HomeGuide 2026; This Old House 2026). Treating before you list is a small, scheduled line item, and it keeps that kind of number out of your negotiation. The complete comparison lives at HVAC mold treatment cost.
On the day, a whole-home disinfection takes about 30 minutes at 1,500 square feet, 45 at 2,500 and 75 at 3,500. You can stay in the house. Keep people and pets out of a room while we spray it. It is yours again 15 minutes later, so it fits between showings. No trip charge. You pay on the day.
See your price. It asks for the heated square feet, and the vent count if you want the air system done too.
What can I show buyers to prove the air system was treated?
You get a treatment record and a 12-month guarantee that transfers to the buyer. It documents that the house and the air system were treated with an EPA-registered product before listing, which answers the question a musty smell or a moisture note would otherwise raise.
Air duct cleaning and treatment covers the registers, the duct work, the cooling coil and the outside of the air handler: cleaned, then treated with BactroKill Plus, an EPA-registered product (EPA Reg. No. 82972-1-90746), applied with an electrostatic sprayer. Bactronix calls that process Bactronizing. Whole-home disinfection takes the same product through the rooms. You receive a treatment record dated before your listing, and the 12-month written guarantee transfers to the buyer at closing.
That is paperwork a listing agent can put in front of a cautious buyer. It does not replace the CL-100. It documents that the air system, the part the CL-100 does not test, was handled by a licensed local contractor on a date you can point to.
Who do I call for the CL-100 versus who treats the ducts?
Two different calls. A licensed pest-control inspector issues the CL-100 for moisture and wood-destroying organisms. We treat the house and the mold in your HVAC and ducts. For mold testing specifically, an independent tester like a local mold-inspection partner handles the lab side.
Keep the roles straight so nobody oversells you. The CL-100 comes from a licensed SC pest-control inspector who grades moisture and wood-destroying organisms. If you want an actual mold test with lab results, that is an independent mold inspector’s job, and we can point you to a local testing partner rather than grade our own work.
What we do is the treatment: find the moisture feeding the growth, clean the surfaces, and apply the EPA-registered product to its label. This is treatment. It is not structural mold remediation, it does not fix an active leak, and moisture that is still wet can grow mold again. Greg Busang owns the company. We do the treatment and leave you the dated record for the listing file. South Carolina’s seller disclosure is knowledge-based, meaning you disclose what you actually know about the property, and it does not mandate a mold test. Treating before you list simply means there is less to worry about disclosing.
If your listing is an established Summerville home, the resale market and the historic-home ductwork details live on the Summerville mold treatment page. For how the room-by-room job works start to finish, see whole-home disinfection, and for the air system see air duct cleaning and treatment.
Frequently asked questions
Does the CL-100 cover mold?
No. The CL-100 covers moisture and wood-decay fungi, not mold in your air ducts. A licensed inspector can flag the excessive moisture conditions that let mold grow, but the report does not test for or certify mold itself. Treating the house and the air system handles the mold the CL-100 leaves untouched. The two are complementary, and treating the ducts is not a way to pass the CL-100.
Will a musty AC smell fail my CL-100 or hurt my home sale?
A musty smell will not fail a CL-100, since the CL-100 grades moisture and wood-destroying organisms, not air-system odor. But it can hurt the sale. Buyers notice the smell at a showing and read it as a hidden problem, and FHA or VA appraisers can stall a deal over visible mold. Treating the HVAC at the source removes the smell before showings start.
Should I treat before listing my house, and what does it cost?
If the house smells musty or you have seen growth around the vents, yes. Whole-home disinfection for mold is $0.30 per heated square foot with a $200 minimum, and your square footage is already on your listing. Air duct cleaning and treatment is $50 a vent on the same visit, however many you have, with no extra minimum. On its own, air duct cleaning and treatment starts at $399. You hand the buyer a treatment record dated before listing plus a 12-month guarantee that transfers at closing.
Do I have to disclose mold when selling a house in South Carolina?
South Carolina’s seller disclosure is knowledge-based, so you disclose what you actually know about the property’s condition. There is no state mandate to test for mold before selling. Treating the house and the ducts before you list simply means there is less to worry about disclosing and a documented treatment record if a buyer asks.
Who do I call for the CL-100 versus who treats the ducts?
Two different calls. A licensed SC pest-control inspector issues the CL-100 for moisture and wood-destroying organisms. We treat the house and the mold in your HVAC and ducts. For an actual mold test with lab results, an independent mold inspector handles that, and we can refer you to a local testing partner rather than grade our own work.
Request a window
Put the heated square feet in above, off your listing, and the vent count too if you want the air system done on the same visit. Pick the day and window that suit you, and we call or write back to lock in the time.