What happens during mold remediation

Why does Texas split the job between two companies?

Texas regulates mold work through the Texas Department of Licensing and Regulation (TDLR) under Occupations Code chapter 1958 and the rules in 16 TAC chapter 78. One rule shapes the whole process: a company may hold both an assessment and a remediation license, but it may not do both the assessment and the remediation on the same project. So the firm that inspects your house and writes the plan is never the firm that tears out the drywall. That separation is the law, and it is the reason the steps below involve two sets of people.

It also explains the bill. A Houston homeowner normally pays an assessment consultant for the protocol and the final clearance, and a remediation contractor for the removal work. Angi's Houston cost data puts mold inspection and testing at an average of $453 and mold removal at an average of $2,016, with a typical removal range of $863 to $3,329. Size, access and how much material has to come out move those numbers in both directions; our Houston mold remediation cost guide breaks that down further.

Step 1: The assessment visit

The process starts with a mold inspection in Houston by a mold assessment consultant. Expect a walk-through of the affected rooms, moisture readings on walls and floors, a look at the AC closet or attic air handler, and questions about recent leaks or storms. Samples are sometimes taken, but they are not always needed; EPA notes that when mold is visible, sampling usually adds little. What matters most at this stage is finding where the water came from and how far the damage reaches, including into wall cavities and under flooring.

Before any mold work begins, the license holder must hand you TDLR's Consumer Mold Information Sheet. Individual license holders also carry a TDLR card showing their license number. You can look up any assessor or remediator on TDLR's license search before you sign anything.

Step 2: The protocol and the work analysis

If remediation is needed, the consultant writes a mold remediation protocol and gives it to you at least one calendar day before the work starts. Texas law (Occ. Code 1958.151) requires a written analysis that spells out:

• the rooms or areas to be worked on
• how much material is to be removed or cleaned in each area
• the proposed methods for each kind of remediation
• the clearance criteria the finished work has to meet

The protocol also covers protective equipment and containment. Read it closely. It is the document that defines success, and it is what you hand to remediation companies so their quotes cover the same scope.

Step 3: Choosing the remediation company and its work plan

With the protocol in hand, you hire a company that holds a TDLR mold remediation contractor license. Tips on vetting one are in how to check a Texas mold company. The contractor writes a project-specific work plan that meets the protocol and gives it to you at least one day before preparation begins. The contractor must follow both documents; if a quote proposes skipping steps the protocol requires, that is a red flag.

For larger jobs, the remediation license holder must notify TDLR at least five days before the project begins. That notice is not required when the mold covers fewer than 25 contiguous square feet. For an owner-occupied home, the initial notification fee is $25.

Step 4: Containment and setup

On the first work day the crew seals off the affected area. Typical setup includes plastic sheeting over doorways and openings, negative air machines with HEPA filters that pull air out of the work zone, and covers on floors along the path to the exit. Workers wear the respiratory protection and clothing the protocol lists. EPA advises not running an HVAC system you suspect is contaminated, because it can carry spores through the house, so the contractor may seal supply and return vents in the work zone or ask you to shut the system off for a time. In a Houston summer that can mean a warm few days, which is worth planning for.

Step 5: Removal and cleaning

This is the part most people picture. What actually happens depends on the material:

Paint or sealant is not a substitute for removal. EPA is direct about this: do not paint or caulk over mold. Some protocols allow an encapsulant on cleaned framing after it passes, but it goes on clean wood, not over growth. For hidden growth behind a shower wall or along a slab-leak line, see mold in walls; for roof deck and rafter work above the ceiling, attic mold removal covers what changes up there.

Step 6: Drying and fixing the moisture source

Mold comes back if the water does. EPA calls moisture control the key to mold control, and stresses fixing the water problem before or alongside cleanup. In Houston homes the cause is often an overflowing AC drain pan, a sweating supply duct in the attic, a plumbing leak under a slab, a window that lets in wind-driven rain, or flood water. A remediation contractor removes the mold; a plumber, roofer or HVAC technician may be needed to fix what caused it. Ask the consultant to note the cause in writing, because it matters for the certificate later.

Step 7: The post-remediation assessment

When the contractor finishes, the consultant who wrote the protocol comes back for post-remediation testing in Houston. The consultant confirms the work area has no visible mold or wood rot, that the work followed the protocol, and that the clearance criteria were met. A consultant who did not write the protocol cannot declare clearance on that project. If the area passes, you get a passed clearance report. If it fails, the contractor does more work and the area is checked again. Keep containment up until clearance; walls should not be closed in before the consultant signs off.

Step 8: Photos and the Certificate of Mold Damage Remediation

Under 16 TAC 78.150, within 10 days after the project ends the remediation contractor must give you before-and-after photos and a Certificate of Mold Damage Remediation (CMDR), a Texas Department of Insurance form. Both the consultant and the contractor sign it. If the consultant finds that the underlying cause was fixed, so the mold is reasonably certain not to return from that cause, the certificate says so.

The CMDR is more than paperwork. For a residential property it can help keep an insurer from making an adverse underwriting decision based on earlier mold damage or claims, though it does not promise any particular result; the details are in our guide to mold and homeowners insurance in Texas. If you sell the house, Texas requires you to give the buyer a copy of every CMDR issued for the property in the five years before the sale. File it with the deed and the roof warranty.

How long does the whole process take?

It varies with the job. A practical timeline includes the assessment visit, at least one calendar day before work for the protocol, the contractor's work plan at least one day before setup, the TDLR five-day notice on larger jobs, the removal itself, drying, and the clearance visit. A small bathroom job can wrap up quickly once paperwork is in place. A flood-damaged first floor, like many homes after Hurricane Harvey, can take much longer, especially when walls must dry before rebuilding. The Houston flood mold guide covers that case.

What if the mold is small?

Homeowners can always clean mold in their own home without a TDLR license, and EPA says a patch under about 10 square feet can usually be handled by the homeowner if the water problem is fixed. The 25-contiguous-square-foot figure in Texas law is an exemption threshold for owners and staff of non-residential property and of residential buildings with 10 or more units; it does not mean the law ignores smaller jobs. Anyone you hire to do mold work for you needs the TDLR license, and a contractor who holds one must follow the rules even on a small job.

Where this applies

The same Texas steps apply across the metro, from a bungalow inside the Loop to a newer slab home in Pearland or a two-story house that needs mold remediation in Katy. To start with a remediation company in the city itself, see Houston mold remediation.