What the South Carolina CL-100 Covers

The South Carolina CL-100 is an official Wood Infestation Report recording visible insect damage, decay and wood moisture readings in a home, on one day. It is not a home inspection and not a clean bill of health, and the two lines around what it covers are drawn in places almost nobody expects.

What is a CL-100 and what is its correct name?

The official name is the Official South Carolina Wood Infestation Report, Form CL-100, and the regulator that publishes it says the two names everyone uses are both wrong.

In Bulletin 16, the Department of Pesticide Regulation writes that the report is sometimes inappropriately referred to as a clearance letter or a termite letter. It is not a clearance letter, because it does not necessarily clear a structure. It is not a termite letter, because it addresses more than just termites. The form itself is approved by the South Carolina Pest Control Association and Clemson University’s Division of Regulatory and Public Service Programs.

That is not pedantry about names. The same bulletin says most South Carolina homes over ten years old can reasonably be expected to have some wood-destroying organism damage, and that the law requires the report to be accurate rather than clear. If you have been told to produce a clear one, you have been told to produce something the state does not ask for. The vocabulary itself is a longer subject, and I have taken it apart in what a termite letter actually is.

Who requires a South Carolina Wood Infestation Report?

A lender, almost always. South Carolina’s own rules do not require a report in order to sell a house.

Section 27-1085(K) of the Rules and Regulations for the Enforcement of the South Carolina Pesticide Control Act is written conditionally. It governs who may issue a report that is issued in connection with a sale or mortgage, and it never says one has to be obtained. The Department of Pesticide Regulation puts the requirement where it actually sits: banks and lending institutions require that homes be inspected for damage from termites and other wood-destroying organisms before they will lend on them. So the answer to who is making you do this is almost always the loan file. Outside South Carolina it is a different form and often a different answer, and I keep those in termite letter requirements, state by state.

Who should obtain and pay for the CL-100?

The South Carolina Department of Pesticide Regulation recommends that the home buyer order and pay for the report. This is a state recommendation printed on the form itself, not a mandatory law.

The recommendation is printed in capitals at the top of the CL-100 and repeated in Bulletin 16, where the Department gives its reason: it ensures that the person with the strongest interest in full disclosure, the buyer, is also the person paying the operator for the report. Read the other way round, that is a plain statement about what a seller-ordered report is exposed to. It is still a recommendation and it is nowhere in the binding rules, so nobody can be made to follow it. If you are the one placing the order, what to specify is in my page on buying a WDI inspection report.

Why does it cover rot in the crawlspace but not upstairs?

Because the two halves of the report have different scopes. Insect damage is reported wherever it is visible and accessible. Decay fungi, decay damage and excessive moisture are reported only below the level of the first main living-area floor.

S.C. Code Regs. 27-1085 K(3)(f) defines that line rather than leaving it to the inspector. The first main living-area floor is the first floor above the basement or crawlspace, or the elevated living-area floor in a house raised on pilings, and the phrase reaches down to include the substructure beneath it. Everything under that line is in scope for decay.

The rule then names both sides of it. Decay damage in the upper portions of exterior siding, fascia and trim boards, chimneys, eaves, soffits and similar areas is beyond the scope of the report. Decay damage in the lower portions of exterior doors, door jambs and frames, steps, stairs, porch columns and similar elements, however, must be reported. Those two sentences sit next to each other in the regulation, and between them they decide whether the rot you are worried about was ever the inspector’s job.

My read is that this is where a clean CL-100 gets over-read. Silence about the wood around a second-floor window is not a finding that the wood is sound. It is the report doing exactly what the rule scopes it to do. What the inspector is actually doing on site is a different subject, and I have covered it in termite inspection.

What do the moisture reading percentages on the CL-100 mean?

A wood moisture reading of 20 percent or higher indicates an excessive moisture condition, while readings of 28 percent and above mark active decay fungi and rot. The inspector must record the exact moisture range measured in your substructure on the face of the form.

Those readings are not optional. The regulation requires representative wood moisture-content readings around the interior perimeter of the crawlspace and in the accessible portions of its center, and requires the readings obtained in the substructure to be disclosed on the report. Bulletin 16 puts it bluntly: any pest control operator not using a moisture meter is not following regulations. A CL-100 that comes back with those fields empty is worth one phone call before it is worth anything else.

One more line in the rule is worth knowing if a wet crawlspace turns into a quote. Fungicidal sprays may not be applied to the substructure until the excessive moisture has physically been corrected first, by a vapor barrier over the crawlspace soil or additional foundation vents. The spray is not the fix and cannot lawfully come before it. What those conditions are and what actually reduces them is in my guide to termite prevention.

What details must the inspector disclose on my report?

The regulation sets a minimum, and it is specific enough to be used as a checklist against your own copy.

Section 27-1085(K)(5) says the report must at a minimum disclose:

• All inaccessible parts of the structure.
• The apparent presence or absence of all visible insect damage in accessible areas. Reporting a previous infestation is explicitly not enough to satisfy that: the rule says so in its own sentence.
• The apparent presence or absence of all visible active and previous infestation in accessible areas.
• The wood moisture-content readings taken in the substructure, along with any decay damage, active decay fungi or excessive moisture below the first main floor.
• The specific location and approximate extent of everything found. Widespread or throughout the substructure are allowed only where the extent and occurrence justify language that broad.
• All damage, whether or not it needs repair or another professional’s opinion, including damage remaining in areas that have already been repaired.

The form adds the mechanical half of that. Every YES on the front is to be described on the reverse, with the item number beside each explanation, and where any active or previous infestation is reported the form states that some degree of damage must be assumed and its location described. None of this is about structural safety, which the report does not assess.

How does an inspector determine if an infestation is active?

The inspector does not get to leave that as an opinion. The rule sends them to published criteria for each organism and then requires them to explain on the reverse of the form the basis for calling an infestation active or not.

For drywood termites, the criteria treat live insects emerging inside the structure, the repeated presence of swarmers alive or dead, which are the winged reproductives, or a repeated accumulation of fecal pellets in one area as reasonable indications of activity. The same passage records that preventative treatment for them is not normally warranted in South Carolina, given how slowly their damage accumulates. What they are and how they differ is on my page about drywood termites.

For powder post beetles, activity means a trail or stream of fresh frass, the powdery droppings they push out, stuck to the wood below emergence holes or piled beneath them, and the color of fresh-cut wood. Emergence holes on their own do not indicate activity, and neither does old dingy frass sitting in holes or galleries. Telling a fresh pile from an old one is the whole question, and I have gone through it in termite droppings versus sawdust.

For old house borers, a live adult or larval specimen has to be collected from the wood, or the distinctive larval gnawing noise heard. Ragged oval exit holes or fresh-appearing frass are not sufficient on their own. If your report does come back with an active finding, what happens next is in failed termite inspection, and the money side of it in negotiating after a termite finding.

Who is legally allowed to sign a South Carolina CL-100?

Only an individual licensed in Category 7A and covered by a valid Pest Control Business License can sign a CL-100. Both license numbers must appear next to the signature.

Signing it also means signing a declaration, and South Carolina’s runs wider than the one on Form NPMA-33. The national form has the company certify that it has no interest in the property inspected. The CL-100 says that, then adds a second sentence: that neither the signer nor the company is associated in any way with any party to the transaction. A realtor’s preferred inspector is a fair question to ask about under wording like that. The national form’s own version is in NPMA-33, box by box, and what a completed one means for a purchase is in what a WDI report means.

Both numbers on your copy can be checked. The Department of Pesticide Regulation runs a license lookup, and separately publishes an enforcement-history database covering the firms it regulates, which Bulletin 16 points consumers to when they are choosing a company. That is an unusually direct thing for a regulator to publish, and it is worth ten minutes before you sign anything. The rest of what I would check on a company is in how to vet a pest control company.

What is left out of the report entirely?

Detached garages, sheds, lean-tos, fences and other buildings on the property are not included unless the report specifically notes them. If the workshop is the reason you are buying the place, that is the line to read first.

Everything enclosed or concealed is out as well: areas behind wall coverings, floor coverings and insulation, anything that would need finished work torn out or marred, and any siding or sheathing that continues below soil grade. Furniture, appliances and equipment stay where they are. There is a way round that one, and the form prints it: on specific request and agreement about an extra charge, the company will open a closed area, inspect it and report on it.

Two more disclaimers are worth knowing about. The inspectors are not engineers or builders, and the form itself suggests calling one for an opinion on whether there is structural damage. And the property was not inspected for health-related mold or air quality at all, which the form says outright the operator is not qualified to judge.

The front of the form also states that the report is valid for 30 days only, which is printed there rather than written into the regulation. That distinction, and every other deadline attached to one of these reports, is in how long a termite letter is valid.

What should I do when reviewing my own CL-100 copy?

Turn it over first. The reverse is where the rule and the form put nearly everything that matters, and a front page of tidy YES boxes with a thin reverse is the version to push back on: every YES described, with its item number, its location, its extent, and the basis for calling an infestation active or not.

Then the moisture range, because two filled-in percentages are the cheapest evidence you have that the inspection met the standard the rule sets. Then the list of inaccessible areas, because it tells you how much of the house the report is actually about.

If damage is reported, the next call is not to the pest control company. Bulletin 16 is direct about this: have a qualified builder decide whether repairs are necessary, forward that builder’s invoice to the mortgage company with the original report, and do not have the operator re-inspect afterwards, because they have already said on the form that evaluating repairs is not their expertise.

I have not seen your report or your house, and both matter more than anything I can say here. What I am confident about is the order: how much of the house was in scope, then what was found, then who is qualified to tell you what it costs to put right.

Sources

• Official South Carolina Wood Infestation Report, Form CL-100 — South Carolina Department of Pesticide Regulation, Clemson University, undated. Accessed 2026-08-08.
• Rules and Regulations for the Enforcement of the South Carolina Pesticide Control Act, S.C. Code Regs. 27-1085(K), Wood Infestation Report (Revised July 2024) — South Carolina Department of Pesticide Regulation, Clemson University, 2024-07. Accessed 2026-08-08.
• Bulletin 16, Understanding Your Wood Infestation Report: A Guide for Home Buyers, Sellers, and Builders (Winter 2007) — South Carolina Department of Pesticide Regulation, Clemson University, archived at South Carolina State Library Digital Collections, 2007. Accessed 2026-08-08.