What This Is
Mold remediation is the professional process of containing, removing, and verifying the elimination of mold growth in a building structure. It is governed by the IICRC S520 Standard and Reference Guide for Professional Mold Remediation. Mold is a naturally occurring organism that colonizes any material with sufficient moisture, organic content, and temperature — conditions that exist throughout most homes. Remediation addresses not just visible mold but airborne spore counts, contaminated materials, and critically, the moisture source that made colonization possible. Without fixing the moisture source, mold remediation is a temporary solution.
When You Need This Service
- ✓Visible mold growth has been identified on walls, ceilings, or structural surfaces
- ✓A musty or earthy odor persists in a specific area of the home, especially basement or crawlspace
- ✓A water damage event (pipe burst, flooding, roof leak) was not fully dried within 48–72 hours
- ✓Air quality testing or home inspection has identified elevated mold spore counts
- ✓Household members are experiencing unexplained respiratory symptoms associated with specific areas of the home
- ✓A real estate transaction requires mold inspection or remediation as a condition of sale
Every Hour Costs You
Active mold growth is not a slow-moving problem — under ideal conditions (wet drywall, 70°F, no UV exposure), common household mold species can double colony size every 24–48 hours. The larger the colony, the higher the spore load in the air, the more building material must be removed, and the greater the potential health impact on occupants with respiratory sensitivities. Mold also structurally degrades the materials it colonizes: drywall paper facing, wood framing, and OSB sheathing all lose structural integrity as mold mycelium penetrate the material. A mold colony discovered early in a wall cavity may require removal of 4 square feet of drywall; the same colony given 30 more days may require removal of the entire wall assembly.
Our Restoration Process
- 1
Independent Mold Testing and Air Quality Assessment
Revolve coordinates a licensed, independent industrial hygienist or certified mold inspector for pre-remediation testing. Testing establishes the mold species, spore counts, and affected area boundaries. This creates the evidentiary baseline for the remediation scope and for insurance documentation.
- 2
Moisture Source Investigation
Every mold event has a moisture source. Identifying and repairing it is not optional — it is the difference between a remediation that holds and one that recurs. Common sources: roof leaks, window flashing failures, plumbing leaks, HVAC condensate drainage failures, and inadequate vapor barriers in crawlspaces.
- 3
Containment Establishment
IICRC S520-compliant containment uses poly sheeting, negative air pressure (air scrubbers exhausting to the exterior), and critical barriers at entryways to prevent mold spores from spreading to unaffected areas during remediation work. All personnel in the containment zone wear full PPE: N95 minimum, Tyvek suits, goggles.
- 4
HEPA Vacuuming and Controlled Demolition
Surfaces are HEPA-vacuumed before any demolition to reduce airborne spore release. Affected materials — drywall, insulation, OSB sheathing — are removed and double-bagged in poly for disposal. Structural framing showing surface mold is treated; framing with deep mycelium penetration is replaced.
- 5
Antimicrobial Treatment of Structural Surfaces
All remaining structural surfaces in the remediation zone are treated with EPA-registered antimicrobial agents. In some cases, encapsulant coatings are applied to surfaces where removal is not practical (large timber framing, etc.) per S520 protocol.
- 6
Post-Remediation Verification Testing
The same independent inspector who performed pre-remediation testing performs post-remediation clearance testing. Spore counts in the remediation zone must be at or below ambient outdoor levels before containment is removed. This is the objective pass/fail standard — not a visual assessment.
- 7
Structural Rebuild and Moisture Source Repair
Revolve's in-house crews repair the moisture source — roof flashing, plumbing, window seal — simultaneously with the rebuild of mold-damaged materials. Drywall, insulation, and finishes are replaced, permits are pulled, and inspections are scheduled. The rebuild is not complete until the moisture source that caused the mold is fixed.
Insurance Coverage
Typically Covered
- ✓Mold remediation resulting directly from a covered water damage event (burst pipe, storm water intrusion)
- ✓Mold discovered during a covered water damage or flood restoration project
- ✓Cost of independent testing and post-remediation clearance testing when required by the claim
- ✓Rebuild of mold-damaged structural materials when connected to a covered event
Typically Not Covered
- ✗Mold from chronic moisture conditions not linked to a specific covered event
- ✗Mold from long-term slow leaks that were known or should have been known to the homeowner
- ✗Mold from inadequate ventilation or humidity control (maintenance issue)
- ✗Many policies have a mold sublimit (commonly $5,000–$10,000) — verify your declarations page
- ✗Remediation costs exceeding the policy's mold endorsement sublimit
Insurance Note
Mold coverage under standard HO-3 policies is often limited by endorsement. Most policies cover mold remediation only when it results directly from a covered water damage event — a burst pipe that caused mold because the water wasn't properly dried, for example. Mold from chronic moisture conditions, long-term slow leaks, or humidity issues is typically excluded. If mold is discovered during a water damage or flood restoration, Revolve includes the mold scope in the same insurance claim and documents the causal connection between the covered water event and the mold growth.
Missouri Mold Disclosure: What Sellers and Buyers Need to Know
Missouri does not have a specific statute mandating mold testing or remediation disclosure in residential real estate transactions. However, Missouri's standard residential property disclosure form, used throughout the St. Louis metro real estate market and recommended by the Missouri Association of Realtors, includes specific questions about known water intrusion, moisture problems, and any history of mold. Answering these questions inaccurately, whether by omission or false statement, creates potential fraud liability under Missouri seller disclosure law.
For homeowners who have experienced mold remediation: a professionally completed and documented remediation, with pre- and post-testing by an independent industrial hygienist, is the strongest possible position in a real estate disclosure. It demonstrates that mold was discovered, professionally remediated to IICRC S520 standards, and cleared by independent testing — a far better disclosure posture than undisclosed mold history or incomplete remediation.
For buyers: if a seller discloses a prior mold event, request the complete remediation documentation — testing reports, scope of work, clearance testing results, and the moisture source repair record. A seller who cannot produce these documents may have had incomplete remediation. Revolve provides a complete close-out package for every remediation project specifically because our clients are likely to face this question in future real estate transactions.
IICRC S520: Why Independent Testing Is Non-Negotiable
The IICRC S520 standard has one requirement that distinguishes it from nearly every other restoration standard: the post-remediation verification test must be conducted by an independent assessor — not the remediating company. This is not bureaucratic formality; it is a conflict-of-interest safeguard. A remediation company that also determines whether its own work passed creates an obvious incentive to declare success prematurely.
Every Revolve-coordinated mold remediation uses an independent industrial hygienist or Certified Mold Inspector for both pre-remediation scoping and post-remediation clearance testing. The clearance standard is objective: airborne mold spore counts in the remediated area must be at or below ambient outdoor levels (or equal to unaffected indoor areas of the same structure). If the remediation does not pass clearance on the first test, the work continues until it does. We do not declare a project complete until independent testing confirms it.
This independent testing protocol also protects your insurance claim. Carriers reviewing mold claims want to see third-party verification of remediation completion, not a certificate from the same company that did the work. Independent clearance testing is the documentation that closes the claim cleanly.
Finding the Moisture Source: Why Remediation Alone Is Never Enough
The most common cause of repeat mold remediation in St. Louis homes is fixing the mold without fixing the water. A basement wall with mold growth from chronic foundation seepage can be remediated perfectly — all visible and airborne mold eliminated, clearance test passed — and will regrow mold within 6–12 months if the foundation seepage is not addressed. Mold is a symptom. Moisture is the disease.
Revolve includes a moisture source investigation as a non-negotiable component of every mold remediation project. Common sources we find in St. Louis homes: failed roof-to-wall flashings that have been leaking for years before mold is noticed in an interior wall cavity; HVAC condensate drain lines that drip onto framing above a finished ceiling; window flashing failures in brick homes with improper sill pan installation; and crawlspace vapor barrier failures that allow ground moisture to migrate into subfloor assemblies.
The moisture source repair is often the most technically complex part of the project and the part most likely to be skipped by a remediation-only contractor who doesn't do construction work. Revolve's integrated model — IICRC-certified remediation partners for the mold work, in-house construction crews for the moisture source repair — means neither step is handed off to a separate company with no accountability for the other side of the project.
Do Not Do This
Do not use an ozone generator in an occupied home or while people or pets are present. Ozone at concentrations effective for mold treatment is toxic to humans and animals. Ozone treatment is an industrial tool for unoccupied structures only, and it does not substitute for physical removal of mold-colonized materials — ozone kills surface mold but does not remove the mycotoxins or structural damage it leaves behind.
Frequently Asked Questions
I found mold on a basement wall. Can I clean it with bleach myself?+
Bleach removes surface mold on non-porous surfaces like tile but does not penetrate into porous materials like drywall, wood, or insulation where mold mycelium are established. DIY bleach treatment on a mold-affected wall gives the appearance of treatment while leaving active mold inside the wall assembly. For any mold on drywall or wood surfaces, professional assessment is needed.
How do I know if the mold is a dangerous species like black mold (Stachybotrys)?+
Visual identification of mold species is not possible without testing — Stachybotrys is black but not all black mold is Stachybotrys. We coordinate independent air and surface sampling to identify species and spore counts. That said, from a remediation standpoint, the IICRC S520 protocol is the same regardless of species — all mold in a structure requires professional remediation.
Our home inspection found mold in the attic. Is that covered by insurance?+
Attic mold is frequently found at home inspections and is almost always the result of inadequate attic ventilation, a bathroom exhaust fan that vents into the attic rather than to the exterior, or a roof leak. None of these are typically covered by insurance as the cause is a maintenance or installation deficiency rather than a sudden covered event. However, if an active roof leak caused by a covered event (storm damage) contributed to the attic mold, the mold scope may be covered as consequential damage.
Does mold remediation require permits in St. Louis?+
Mold remediation itself does not require a permit in Missouri. However, the structural work that follows remediation — replacing drywall, framing, roofing — typically does require permits. Revolve pulls all required permits for the rebuild phase and coordinates all required inspections.
What is an industrial hygienist and do we really need one?+
An industrial hygienist (IH) is a certified professional who assesses environmental health hazards including air quality, mold, and asbestos. For IICRC S520-compliant remediation, independent pre- and post-remediation testing by an IH or Certified Mold Inspector is the standard. We coordinate this testing as part of every project — it is not an optional upsell.
We're trying to sell our house and the buyer's inspection found mold. What's the fastest path forward?+
A documented, IICRC S520-compliant remediation with independent clearance testing is the only defensible path for a real estate transaction. We can typically complete pre-testing, remediation, and clearance within 2–3 weeks for contained events. We also provide the complete documentation package the buyer's agent will need to confirm remediation was professionally completed.