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What Is Involved In A Post-Remediation Verification?  
  Simply stated; post-remediation verification testing (also called clearance testing) is the inspection and retesting of areas in a building that have undergone remediation work to ensure that the remediation was successful.

Success is defined as follows:

  1. No visible mold growth on any of the construction materials.
  2. All construction materials are dry by current industry standards.
  3. The cause of the original problem has been resolved.
  4. The indoor air quality is within acceptable standards.
  5. Cross-contamination of non-work areas has not occurred.

1. No visible mold growth on any of the construction materials.

Picture of construction materials after mold removal.The goal of mold remediation is NEVER to KILL mold, TREAT mold, or COVER mold up with paint or other solid color coatings. The goal of mold remediation is ALWAYS to REMOVE the mold.

The picture to the right is from the first floor of a house that had a flood in a second floor bathroom. The flooding occurred while the owners were away on vacation. By the time was discovered most of the drywall, cabinets, wood trim and floor coverings were destroyed. The framing materials you see in this picture were covered with mold growth from top to bottom. To the mold remediation contractor's credit, the lumber was completely mold free and restored to like-new condition.

Picture of construction materials that were not properly cleaned of mold growth.Unfortunately, not all mold remediation contractors are equally as thorough and conscientious about their work.

This picture is a testimony to why it is never a good idea to let contractors perform their own post-remediation verification or clearance testing. Both of these contractors claimed that the remediation work was complete and the jobs were ready for reconstruction. Yet it is quite clear that the second picture still has visible mold growth. Ironically, the contractor of the job in the second picture argued that the remediation was successful by virtue that it was "as good as he could get it".

Why is it so important to REMOVE the mold?  For two reasons:

#1. Mold that has been killed, treated, or covered up can always begin grow again if moisture reoccurs - even if the moisture is just high humidity.

#2. Dead or dormant mold still releases mold spores into the air. While mold must be alive to cause further property damage, dead mold spores - when inhaled - have the exact same effects on people and animals as mold that is alive. Mold can be killed, treated, or covered up but if it is still in your building, all of the health risks associated with mold are still there to.

In a Post-Remediation Verification, a visual inspection of all construction materials inside the containment area is conducted to determine whether of not all visible mold growth has been removed.

2. All construction materials are dry by current industry standards.
Mold grows on wet construction materials. Inexpensive mold contaminated materials such as drywall, wood trim, cabinets, etc. are typically removed and replaced. Other materials that are generally too costly to replace, such as wood framing, studs, joists, etc. can usually be remediated by scraping, sanding, and wire brushing off mold growth.

Picture of construction materials that were still wet after mold remediation. THe blue spot in the infrared picture shows moisture.Equally as important as removing mold growth is the complete and thorough drying of all salvaged construction materials. The blue areas in the picture to the right are wet spots in the framing lumber. The remediation contractor said the job was complete and ready for post-remediation verification. In this case, no visible evidence of mold was present on any of the remediated materials. However, if new drywall had been installed over this wet lumber, mold would have begun to grow within 2 to 3 days.

In a Post-Remediation Verification, a moisture assessment is performed inside the containment area to confirm that all construction materials are dry in accordance with current industry standards.

3. The cause of the original problem has been resolved.
Picture of construction materials after mold removal that were not dried thoroughly.In a Post-Remediation Verification, a visual inspection is performed  inside the containment area to confirm that the source of water intrusion that caused the mold growth has been remedied.

This is a picture of a remediated containment that the contractor claimed was ready for reconstruction. You can see by the dark stains on the framing lumber and sub-floor that the plumbing leak that caused the mold problem to begin with has not been resolved. Any new materials installed here would have been wet immediately. New mold growth would be certain within 2 to 3 days. Obviously, this remediation was unsuccessful.

4. The indoor air quality is within acceptable standards.
The final test of a successful remediation effort is the sampling of air from inside and outside of the containment area. According to current industry standards, after remediation the types of airborne mold spores present inside a containment - and their respective levels - should be the same or less as outdoors.

Test result are simple and straightforward. If there are 5 molds in the outdoor air and 8 in the containment air, the remediation was unsuccessful. If airborne spore levels in the containment are higher than outdoors, the remediation was unsuccessful.

In a Post-Remediation Verification, air sampling is performed to confirm by means of analytical data, that which cannot be confirmed visually.

5. Cross-contamination of non-contained work areas has not occurred.
When suspicious conditions are visually observed which raise concerns that cross-contamination may have occurred in other parts of a building during the remediation process, testing the air in those areas is done to confirm or rule out that concern.

Cross-contamination typically occurs when a containment area has been breached and mold spores have been blown out of the contained work area and into other parts of the building. Suspicious conditions that cross-contamination has occurred include:

  • poorly installed containment walls and doors
  • tears, holes, and broken seals in the containment plastic or tape

The following pictures will help you recognize the difference between a proper containment job and an improper one.

Picture of sub-standard mold remediation containment doorway.
This was the entry way to work area. The excessive use of tape indicates the contractor was having multiple problems keeping the plastic wall intact.
Closer look at the sub-standard mold remediation containment doorway shows gapping hole at bottom.
Tearing and significant gaps are seen between the plastic and the tape that is intended to secure it. Mold-filled air from inside the work area was being blown into a non-work area by filtration machines.
Picture of a very unprofessional attempt at building a mold removal containment area. Bad job at mold remediation containment shows tape did not adhere to floor.
This was a make-shift 3-sided containment wrapped so closely around kitchen island cabinets that there was no room to work inside. The worker broke the tape seal several times and made no attempt to repair the breach. Seen here is 1 of 2 breaches in the tape seal at the floor. It had been broken so many times that the tape no longer had enough glue to hold the plastic down. Mold-contaminated air passed into the kitchen with unprotected cabinets.
Picture of a perfect, professionally built mold abatement containment area. Picture of the inside of a professionally built mold remediation containment area.
This is an example of a  properly installed containment area. Unlike the make-shift example above, metal pole framing was used to keep the plastic tight and straight with no breaches in the tape seal. Even though the actual remediated area was a small section of wall, the contained area is large enough to work in without damaging any of the materials or putting stress on tape seals.
Mold remediation containment doorway properly sealed to floor. Mold remediation containment doorway improperly sealed to floor - not taped down.
Close but no cigar! This contractor did an excellent job at installing the containment materials. One worker was assigned to this room. Another to the room on the right. The plastic was tight and sealed perfectly in one room.
But the plastic in the room right next to the one on the left was never sealed at the bottom. Because of this oversight, the entire first floor of this ocean-front home was contaminated with mold spores.
Choosing A Qualified Remediation Contractor  
  Before choosing a "qualified" mold remediation contractor consider this:  
  1. Not all mold remediators are licensed contractors.
Currently in most States including California, there are no licensing requirements for people who remove mold. In California, removing mold is classified as janitorial work. That means that legally, anyone who can wash windows or sweep floors is allowed to perform mold remediation. This is important to know because many mold removal jobs require the removal of cabinetry, plumbing fixtures, electrical fixtures, and HVAC components, all of which should only be removed or installed by licensed carpenters, plumbers, electrical contractors. For that reason, it is important to know your mold remediators legal qualifications to address the entire scope of work, and not just the removal of mold.

The best person to trust your mold remediation work to is a licensed contractor who is certified to perform mold removal. See more on certifications for mold remediation contractors below #3.

  2. Not all licensed contractors are mold remediators.
If you or a loved one had a life-threatening condition that required brain surgery would you choose the best brain surgeon you could find or a podiatrist that came highly recommended by Aunt Martha? Obviously that is a rhetorical question. Yet every day people choose highly qualified repair contractors to do mold removal work that they are not qualified to do.

There are many excellent, reputable licensed contractors who are highly-qualified to perform room additions, kitchen and bathroom remodels, and even construct an entire building from the ground up. But that does not necessarily qualify them to perform mold remediation. Proper and safe mold removal requires specialized knowledge and expertise. If mold remediation work is not done properly, significant collateral damage can occur to other mold-free areas of a building by cross-contamination of airborne mold spores. Furthermore, failure to implement adequate safety measures to protect the occupants of a building before, during and after remediation work can result in serious health risks and costly litigation.

Choosing the best kitchen and bath contractor to perform mold remediation work is rarely a wise decision. It is always best to hire a certified mold remediation contractor to perform mold remediation.

  3. Always Choose An AmIAQC or IICRC Certified Contractor

stands for American Indoor Air Quality Council. In mid 2009 the AmIAQC was renamed the American Council for Accredited Certification (ACAC) to better reflect the exclusive prestige of being the only IAQ certifying body with CESB accredited certifications.

Council-certified mold remediation contractors are
required to maintain the highest industry qualification standards including a rigorous continued education credits program and mandatory recertification every two years. When searching online for a Council-certified
mold remediation contractor look for one or both of these logos.

IICRC stands for Institute of Inspection, Cleaning and Restoration Certification. IICRC is a non-profit certifying body for cleaning and restoration professionals. It was founded in 1972 to establish and monitor educational programs and standards most phases of property restoration. When
searching for an IICRC certified mold remediation contractor
online search for this logo.

Again, the best person to trust your mold remediation work to is a licensed contractor who is certified to perform mold removal. The second best would be one who may not be a licensed contractor but who is certified by one of these two certifying bodies. The least desirable choice would be a licensed contractor with no mold remediation certifications.

One last note on choosing a mold contractor.  A Council-certified or IICRC certified mold remediator is always the best place to start. But always ask for at least three references and never assume that a contractor must be OK just because they give you references. CALL THEM!  In fact, always ask for references that are at least one year old and call them. Why? Because right after a mold removal job is done everything looks great and everyone is happy to be rid of their mold. But if that job was not done right it might take 6 to 9 months before anyone knows it. A referral might have nothing but praise for the contractor immediately following a job, but nothing good to say about him a year later.

Get referrals and call them. Call the State Contractors Board to check on their license. Call the Better Business Bureau to check their rating. If you don't get satisfactory answers, call another contractor.


Who Pays For Post-Remediation Verification?  
  You do!  That's another reason why it is so important to choose the right remediation contractor. If a remediation job fails to meet industry standards the contractor must find out why and correct the problem. Then the work must undergo a second post-remediation verification. And if that fails, a third. And if that fails, a fourth. And every post-remediation verification costs the same as the first one.

During the interview, talk to your contractor about post-remediation verification (also called clearance testing). Most contractors do not pay for testing. If they do they usually insist on doing it themselves or having someone they know do it. But even the best contractors don't fail their own work. For obvious reasons it is always in your best interest to have a third-party independent Inspector perform clearance testing.

If you paid to get rid of a mold problem and the clearance test fails, you still have a mold problem. If you still have a mold problem, you will be dealing with it again sooner or later. An independent testing company can help you avoid future problems by insuring that your remediation job was done properly.

Here are a few tips to help you better understand post-remediation verification. Discuss these things with your contractor.

1. Tears, holes, and gaps in containment materials can cause a clearance test to fail. Additionally, breached containments cost more because areas outside the contained work space require testing to confirm or rule out cross-contamination.

Increase the likelihood of first-test clearance with air-tight containment. Stay out of the containment during remedial work. Traffic in and out increases the probability of a breached containment and a second test.

2. Post-remediation verification should be done after all the mold has been removed but before any new construction materials are installed. The Inspector should be able to examine all salvaged remediated materials. If new drywall is installed and the clearance test fails, the new drywall will likely have to be removed to find out why.

3. If anti-microbial coatings are going to be applied, (a step some contractors call "encapsulation"), it should be done after verification as a precautionary measure to help construction materials resist moisture in the future, not to cover up water stains or hide mold growth. If for some reason the contractor chooses to encapsulate prior to verification, only clear coatings should be used. Solid color coatings, paint and stain hiding products like Kilz are often used on framing materials to cover up mold that was not removed. A containment full of freshly painted wood framing may look nice, but if the clearance test fails it is virtually impossible to see why.

Ask your contractor if anti-microbial coatings are going to be used. If so, insist on clear products only. Also, Kilz is strictly a paint and should never be used as an encapsulant. It is not an anti-microbial coating nor does it have any water-proofing properties whatsoever. It serves only one purpose; to cover stains. Often times water damaged framing wood is permanently stained and damaged. But there is a distinguishable difference between water-stains and mold. Water stains don't fail a clearance test, mold does - even when it is painted over with Kilz. 

The best way to minimize post-remediation clearance testing costs is to educate yourself on the remediation process from start to finish. Recognizing when something is wrong early in the process can save time and hundreds, even thousands of dollars as the job draws to a close.

If you have questions or concerns about clearance testing that are not addressed here, please feel to call AMI at 1-800-369-8532 and speak to a Certified Post-Remediation Specialist.


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