5 Steps to Proper Mold Remediation


Follow these steps for quickly remediating mold problems

By Michael Dickens, BuildIQ | November 29, 2018
Mold remediation_important issue_steps to take to address mold problems for builders
Photo: Unsplash/Michael Schiffer

Mold has had its 15 minutes of fame over the last few years. Though the hype has died down, mold is still an important issue. Customer complaints require home builders to have a fast action plan; both to clean up the mold problem and to show customers a quality home builder is looking out for their health and safety and the durability of their home.

There are two important things to remember about mold: prevent it by doing things right the first time and when you do face mold, take care of it immediately. Ensuring that your warranty team follows a process for mold remediation will take care of the latter.

The following steps, which can be adapted to fit within your company's policy, serve as a basic process for quickly remediating mold problems.


Step 1: Learn about moisture


Assessing mold growth involves more than just looking at what's visibly growing on the walls or in a corner. Mold can be an invisible intruder, growing behind and around what you first see. Such devious behavior requires inquisitive thinking.

First, understand that behind all mold growth is a water or moisture problem. Second, become a master of moisture — know where moisture comes from and how it gets into the home. The ultimate goal of these two steps is for warranty representatives to identify a moisture source and use its location to help locate all mold growth, not just what's immediately visible.


Step 2: Document the mold problem and create a remediation plan


Before you begin remediation, document the mold situation with writing, photos and video. The warranty team supervisor will use the documentation to develop a remediation plan, which typically answers questions like when work is slated to begin, when that work is scheduled to be completed, who will be performing the remediation, any testing that should be done, and if homeowners will be temporarily relocated. In the longer term, the documentation can help manage liability for your company or point to larger trends in mold growth.


Step 3: Calculate the extent of the contamination


Mold may not always grow in one area, so you need to figure out how much contamination you're really looking at. Calculating the extent of the contamination will impact how you approach mold removal and clean up. The goal of mold remediation is to clean up mold growing within the home, and to avoid exposing homeowners to large amounts of mold.

The New York City Department of Health (NYC DOH) has developed guidelines for cleaning up mold contamination. These guidelines are widely used in the construction industry and recommend six levels of mold remediation based on the square footage of the mold and whether or not the mold is located within the home's HVAC system. Following the NYC DOH's guidelines, available online, calculate the remediation level needed.


Step 4: Remediate mold contamination


Remediation will always involve cleaning up existing mold while avoiding exposure to oneself as well as homeowners, as well as preventing new growth by addressing the moisture source. Based on your calculation of the contamination area, determine if you're working in an area up to 30 square feet (approximately the size of a full sheet of drywall). If so, you'll be following the guidelines for remediation levels 1 and 2. Level 1 remediation is used for small, isolated areas of mold up to 10 square feet and Level 2 remediation covers square footage from 10 to 30 square feet.


The cleanup process is the same for Level 1 and Level 2 mold remediation and comprises these steps:

  • Repair the water problem. This will help prevent new mold spores from growing.
  • Isolate the contaminated area. Close all doors and windows between the contaminated area and other rooms of the home for both levels. For Level 2 remediation, also cover all doorways and any other openings with 6 mil polyethylene sheeting. Seal all seams of the sheeting with duct tape and slip openings in the sheeting to enter the contaminated area.
  • Suppress dust. Do this by misting the contaminated areas.
  • Remove materials. Remove all wet and mold-damaged porous materials. Check with your supervisor and reference the Environmental Protection Agency (EPA) document, Mold Remediation in Schools and Commercial Buildings if you're not sure which materials to remove.
  • Place materials in plastic bags. Discard all wet and moldy materials in plastic bags that are at least 6 mil thick, double-bag the materials, and tie the bags closed. The bags can be disposed of as regular trash once the outside of the bags are wiped with a damp cloth and detergent solution prior to leaving the contamination area.
  • Clean. All non-porous materials and wood surfaces that are moldy must be cleaned. Use a wire brush on all moldy surfaces and then wipe the area with disposable wipes. To dispose of as regular trash, discard wipes in 6 mil polyethylene bags, double-bag and tie closed. Finally, scrub all moldy surfaces using a damp cloth and detergent solution until all mold has been removed and rinsed cleaned surfaces with clean water.
  • Clean the affected area and egress. The process for Level 1 differs from Level 2 at this point. For Level 1, clean with a damp cloth and/or mop with detergent solution. Level 2 requires you to vacuum all surfaces with a HEPA vacuum, and then clean all surfaces with a damp cloth and/or mop and detergent solution. Discard wipes as described above.
  • Visibility test. All areas should be visibly free of contamination and debris — no dust and dirt means no mold.
  • Dry. Cleaned materials should be dried to allow leftover moisture to evaporate. To speed up the drying process, use fans, dehumidifiers or raise the indoor air temperature.
  • Replace. All materials that were moved should be replaced or repaired.


Reference the remediation plan during the actual remediation to make sure it's being followed. If additional mold is discovered during the clean up, the warranty supervisor should update the plan.

For contamination areas greater than 30 square feet, many builders hire outside mold remediation firms to perform the clean up. In this case, you and your team switch from actually performing mold remediation to supervising a qualified contractor. Having a general understanding of the proper procedures an outside company should be following is useful. The NYC DOH guidelines address such procedures for Level 3 contamination and above.


Step 5: Determine if clean up has been successful


Just because the mold is gone and there's no dirt or dust doesn't mean that you're done. Your last step is to determine if your clean-up efforts have been successful. While this last step is a judgment call, there are some options and guidelines to follow.

The EPA document, Mold Remediation in Schools and Commercial Buildings, is a great resource that provides guidelines for helping you complete your clean up efforts. Some of these guidelines include:

  • The moisture problem has been fixed. Verify this by revisiting the home soon after remediation — you shouldn't see any signs of recurring water damage.
  • No sign of visible mold, mold-damaged materials or moldy odors.
  • Homeowners should be able to occupy or re-occupy the home without physical symptoms or aggravated health complaints.


Depending on your company and the specific details of a mold problem, additional testing by an environmental testing company may be performed after the clean up to verify that all mold has been removed.

When it comes to mold, the key is to implement a comprehensive moisture management strategy. Potential liability and health issues from mold can be dramatically decreased by doing it right the first time. Clean up must be immediate and thorough, following a process like the above steps. It may sound over-simplified, but the primary failure in response to homeowner complaints is simply the fact that builders don't respond fast enough, or with the emphasis that the issue is potentially serious.

Minimum personal protection equipment for levels 1 and 2 remediation includes an N95 respirator, eye goggles without vents and rubber gloves that extend to mid-forearm.


Got Mold?


Following an immediate and thorough remediation plan is essential for getting rid of the mold and showing your customers you're committed to acting quickly.

Before entering a home to assess a mold growth situation, make sure you have the necessary personal protective equipment.


Submitted by Andy (not verified) on Tue, 12/12/2017 - 00:01


The article doesn't say anything about what chemicals to use to kill or remove the mold, or how strong to mix them, such as bleach, 1-4 or 1-6, etc...
I would like to know if there are economical alternatives to bleach.

Submitted by Michelle at th… (not verified) on Wed, 01/24/2018 - 11:33


Hi! I have a question about how to test for unseen mold in an old, adobe building. Our office is a house that's 100+ years old and may or may not have a mold problem. We cannot see it, but we can smell something, We bought a ProLab test kit (for vacuum), but since we have no carpet (it's tile), crawl spaces, basement, drywall, wallpaper, attic, etc. we've been told that this is not the optimal test. Is there a Petri dish type test that can measure air quality? Thanks! Michelle (michelle@taoslandtrust.org)

Submitted by Griselda L. Mayorga (not verified) on Sat, 09/08/2018 - 16:27


I have some question about mold issues at the apartment:
If any company will make any mold remediation repair the tenants should move during these mold remediation repairs?
I want to know the differences between mold mitigation and mold remediation?
If after any mold remediation the tenants have any respiratory problems , should order any airborne test to detect any mold spores?
My email is gris403@hotmail.com

Submitted by Candace Jones (not verified) on Mon, 09/17/2018 - 15:54


I got mold due to a leaky sink. The insurance Company gave me money for demolition. They dont pay for my plumbing issue. My sink(the source of the leak) should it be replaced by the insurance company but not the labor. Also does demolition money is suppose to pay for the demolition and putting new walls and floors after the remediation or should the insurance pay separate for the material and labor to put the bathroom back together

Submitted by Matthew Valdez (not verified) on Tue, 02/12/2019 - 17:27


This is a really helpful article. As someone who's been working in the industry for a long time, (can I say a long time, since 2011), I like how you referenced the EPA and the NYC DOH guidelines. There are a lot of hacks out there making a mess in peoples homes.

Our national franchise has a similar process they've listed; of course ours is 7 steps which isn't necessarily better. You can see it here, https://www.servpronorthcentralcoloradosprings.com/mold-remediation

As your article references, what good is restoration without following up to see if you were actually successful.

Thanks! Matthew.

Submitted by Cathy Bennett (not verified) on Sun, 03/03/2019 - 11:49


We have mold in a kitchen wall. So far we have discovered 2 sources of leaks. Many fixes have been done. The wood is dark in this wall due to the moisture it held. Should this wood be replaced?

Submitted by Al Hall (not verified) on Wed, 04/10/2019 - 10:47


A petri dish will almost always give a positive for mold because it is ubiquitous. Get an air sampling test kit like My Mold Detective to get a quantitative measure of mold spores & types in your air. Or higher an IAQ or Mold Inspector. Have them prove their certification(s).

Submitted by Nathan Linfoot (not verified) on Thu, 06/27/2019 - 11:35


Hi, I don't know if this was answered already but the best way to check for mold in this case would be an air sample, you will want to get a base line outside to confirm the baseline for the area and environment. Then you will want an air sample inside and you don't want those numbers to be too much more than outside, indicating normality in the environment. Sometimes this can be costly though, a cheaper way would be to check the basement/crawlspaces and the attic area for moisture and for visible mold. The do it yourself method would be to use a hydrogen peroxide solution to clean it. For the moisture I would recommend contacting a private contractor/indoor air quality specialist for the best operation in remediating that problem.

Hope I could help!

Submitted by ana (not verified) on Fri, 08/16/2019 - 20:20


Contractors came, demolition was done, they placed contaminated material and items and other clean rooms without using plastic bags, wet my carpet with moldy water. Is this something I need to worry about it, and what can I do?
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