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The Basics of Mold Remediation – Part II of III – Gross Removal of Mold Growth and Impacted Materials

mold removal

See my post “The Basics of Mold Remediation – Part I of III – Containment of the Affected Area” for background information important for understanding this part of the mold remediation process. At this point in our process, the mold impacted area has been isolated from all non-affected adjacent living spaces. This was accomplished by establishing containment of the area, which included the installation of HEPA Filtered Negative Air machines and installation of physical barriers which, in turn, would have created a negative pressure environment. The next step is to perform the removal of impacted materials and mold growth.
 Part II of III – Gross removal of mold growth and impacted materials

Unfortunately, when a mold problem is present within a home it typically means that some materials are going to have to be removed. If mold growth is within a wall cavity or under flooring materials, to be accessed, the materials around the source must be removed. If mold and/or water damaged non-structural materials are present, they are typically removed and discarded. These types of materials would include: baseboards, drywall, carpeting, carpet pad, tack strip, underlayment, insulation, building paper, etc. The bottom line is that most remediation projects involve the demolition of building materials. The removal of materials is typically well planned and, on most projects, only the necessary materials will be removed while salvaging the non-affected materials.

Once the removal of the non-structural materials is accomplished, mold growth must be cleaned and removed from the structural materials. Mold is often found growing on organic structural materials such as framing, subflooring, roof sheeting and just about any organic material that is used in construction. As long as the structural integrity of these materials has not been compromised, the mold growth will be cleaned and removed from the materials. The first step in this process is to HEPA vacuum the surface of these impacted materials. This is done to remove as much of the mold source as possible in a controlled manner in an effort to prevent the mold spores from becoming airborne. Next, the impacted materials are scrubbed and cleaned to remove all physical mold growth. This is a very important step because mold sources imbed themselves into the materials they are feeding on with hyphae. Hyphae are thread like components of the mold used to bind itself to the material and can penetrate it as far as a 1/32nd of an inch. Some contractors will remove the hyphae with wire brushes or sanding, while others may use more intense methods such as dry ice blasting or media blasting. Either way, the mold must be removed in its entirety. This process typically creates lots of dust and debris, so HEPA vacuuming is often done in combination with the cleaning.

During the cleaning of the structural materials, many contractors use liquid based cleaning products in combination with the cleaning. This is done for multiple reasons: to physically kill the mold, to penetrate the affected materials and aid in loosening the hyphae, to wet the mold source and make the spores less likely to become airborne, to bleach the materials and remove evidence of staining, etc. There are many different types of products used: some are “Green” products considered to be environmentally safe, some are biocides designed to kill all biological organisms, some are fungicides designed to kill fungal based organism, and some are based on everyday homeowner liquids such as Hydrogen Peroxide (quite a bit stronger then the stuff in your medicine cabinet though).

Once all of the impacted non-structural materials have been removed, and all of the physical mold growth has been cleaned and removed from the structural materials, the next step of the remediation project may begin. Stay tuned Part III of a basic mold remediation project…

Brandon Apple

by Brandon Apple, Mold Inspection Sciences


June 7, 2012 at 9:55 am

The Basics of Mold Remediation – Part I of III – Containment of the Affected Area

Mold remediation containment

Mold Remediation Containment

Mold remediation HEPA Filtered Negative Air Machine

Mold remediation HEPA Filtered Negative Air Machine

One of the main intents of an initial mold inspection is to identify whether or not you have a mold problem. This can obviously lead to one of two outcomes: 1) You do not have a mold problem and your concerns were alleviated through a thorough mold inspection and/or testing, or 2) You do have a mold problem and proper mold remediation should be performed. I don’t know about you, but I would be hoping for option one. But, unfortunately, a lot of people end up in situation number two. The next step to properly address the situation is to enlist a certified, competent remediation contractor to perform mold remediation (removal of mold) in the affected area. This can be a pretty in depth process, but for the sake of this article (and the next two to follow) we shall break it down into three basic steps.

Part I – Containment of the affected area

When a remediation project is initiated, the first step is to set up containment (isolation) of the affected area. One of the concerns when indoor mold is present is the resulting airborne mold spores. Containment will help control the spread of these spores, while assisting the remediation contractor in returning the affected area to normal conditions. The act of removing or disturbing a mold source tends to distribute large quantities of mold spores into the air. If proper containment is not utilized, this can affect adjacent spaces to the work area and cause cross contamination.

The first step to setting up containment of the work area is installing a HEPA Filtered Negative Air machine. This is a fan that is set within the work area which pulls air from the area which is typically exhausted outside of the structure via flexible tubing or ducting. Doing this will begin to draw any airborne mold spores away from the airspace eventually creating a negative pressure environment, which we will be discuss later in this article.

Step two is to install physical barriers in the work area. This is most typically done with the use of heavy plastic. The main goal when creating this physical barrier is to completely isolate the work area from any adjacent, non-affected areas. For example, if mold is present in one room of your home and the adjacent areas have not been affected, the room must be isolated. Depending on the layout, the doorway would be completely sealed with plastic. All HVAC systems or shared airways between other rooms would be taped or covered in plastic. All electrical outlets and light fixtures would be covered. In essence, any area that could allow air communication between the work area and other non-affected areas should be properly sealed.

Once step one and two are completed, a negative pressure environment should be created. A negative pressure environment simply means that the air pressure within the work space is less than the air pressure in the areas surrounding that space. This is achieved when the volume of air being pulled out of the space (through the negative air machine) is greater than the volume of air being pulled into the space. As a result of this negative air pressure within the work space, any mold spores that become airborne through the remediation efforts are being controlled, preventing them from affecting the adjacent spaces and flushing them away from the indoor environment which is necessary when attempting to return the area to normal conditions.

Once these steps have been completed, the remediation contractor would then begin Part II of a basic mold remediation project. Stay tuned for what happens next…

Brandon Apple

by Brandon Apple, Mold Inspection Sciences

May 11, 2012 at 9:20 am 2 comments

The Importance of an Outside Control Sample

Air sampling for moldPart of a proper mold investigation, is collecting ambient air samples in relation to suspect conditions within a home. This helps us determine if there are “suspect” or “elevated” airborne mold spore types and/or concentrations. This not only helps us in determining if hidden mold sources are likely, it helps us determine the overall impact mold is having on the environment and in turn allows us to give proper recommendations for remediation (the removal of mold).

To properly asses the indoor conditions, we must first collect an outside control, or baseline sample. This is necessary because we always have to remember that airborne mold spores are everywhere, so even a home that does not have a mold “problem” will have some mold spores within the air. For a sample to be considered “normal” it should be somewhat consistent with the outside control sample taken that at that same day and time. In general indoor spore counts should be roughly 75% of the outdoor counts and usually proportionately similar in terms of spore types.

We do get asked all the time though “well, why can’t we just use averages from previous samples to determine a baseline?” Great question, and at first glance it does seem like a reasonable method, but in reality it just doesn’t work that way. Averages are used to some degree in the analysis of air samples, but an average is just that, an average. The spore types and concentrations in our environment can swing drastically due to multiple factors that influence our environment. Mold is a living organism, and therefore it reacts to its environment conditions. So, if it has been wet and rainy out and the mold sources are, let’s say happy, then they may not be actively sporelating and releasing mold spores into the air. On the flip side of that, when conditions are dry, mold sources typically begin sporelating in an effort to spread out and find additional water and/or food sources. On windy days, we sometimes see very high spore concentrations. And when there is snow on the ground, we will typically see very low spore concentrations.

As a result of all of these influencing factors, it becomes apparent that averages just do not give us enough information to properly assess indoor airborne mold conditions. To fully understand if there is a mold “problem” within a home, it is important to have as much information as possible. And a big piece of information that helps us do that, is analysis of airborne mold spore concentrations as compared to an outside control sample. If you believe you have a mold problem, consider engaging a competent and certified mold investigation specialist to perform a thorough mold investigation and proper mold sampling.

Brandon Apple

by Brandon Apple, Mold Inspection Sciences

April 19, 2012 at 8:57 pm 1 comment

We Live, Eat and Breathe Mold

Eating Mold CheeseThe other day, I was on a call with a client. We had performed a mold inspection and microbial testing for them, and their results were… let’s say less than typical. There were a lot of possibilities, and sources, and we talked through all of their options as far as moving forward. At the end of the conversation, the client thanked me, and said that I seemed to know a lot about mold, and my time was appreciated. I replied with a simple joke: “Hey, it’s not hard when all you have done for the past 10 years is live, eat and breathe mold”. We had ourselves a good chuckle, and ended our conversation there. But, it didn’t quite end in my mind, and I started thinking about that comment. What I realized is that we all live, eat and breathe mold every day of our lives. Let me explain:

We Live Mold – Mold in our homes is definitely considered to be a bad thing. However, mold outside of our homes is actually a necessary organism, and adds to a healthy ecosystem. Its purpose is to break down dead, organic material such as plants, trees and animals. Without mold, those materials would just sit around, and start to pile up, and let’s face it, make the world a pretty yucky place. If it weren’t for mold, we would live in a very different world. It could even stand to reason that if there was not mold, humans as we know ourselves might not be around today. So, in essence, we live, in part, due to mold.

We Eat (and drink) Mold – This is an easy one. Mold is actually used in multiple types of food. Whether it be the mold used in the production of certain cheeses, or fungi (which is in the same family as mold) used to create bread, wine and beer. So, I guess you could say we all eat (and drink) mold.

We Breathe Mold – Believe it or not, we all inhale mold on a day-to-day basis. In fact, 99% of you reading this right now probably just took a breath that had some good old mold spores in it.  Mold, because it is a natural part of our environment, is everywhere!  Mold spores, which is what a mold source uses for reproduction and spreading out looking for new food and water sources, are most commonly distributed via airflow. This is happening on a daily basis outside, and as a result the spores are widely spread throughout our environment. As a result, those spores infiltrate our home through open windows and doors, through invisible cracks in the home envelope, through natural and mechanical ventilation, and on our clothes and contents coming into the home. Almost every breath you take will invariably have some amount of mold spores within it. So, every single one of us breathes mold on a daily basis.

When you put all this together, you find that we all “Live, eat and breathe mold”. That being said though, as with everything there can be too much of a good thing. When mold is originating from an indoor source, and we are exposed to excessive amounts of mold spores and/or byproducts of mold (mycotoxins), we can experience health effects. If you believe that you might have a mold problem within your home, the best thing you can do is consult with a certified Mold Investigation Specialist. Through a thorough mold investigation and microbial sampling process, they can help you determine if you are dealing with normal mold conditions, or something that needs to be professionally remedied.

Brandon Apple

by Brandon Apple, Mold Inspection Sciences

March 31, 2012 at 1:08 pm

Good Mold vs. Bad Mold

Good and Bad Mold

Being in the mold inspection industry, we get asked all the time: “Is it good mold or bad mold”. To be honest, this is a tough question to answer. I think instead of looking at it as good vs. bad, it should really be lumped into 3 categories: Good, Normal, and Bad.

Let’s start with the good, shall we? Molds can be good when they are used for medicines, or in the production of certain cheeses, and let’s be honest, mold that is Outside our home is typically considered to be a good thing. So, most people don’t even notice mold when it’s good, unless they are reaching into the fridge for that stinky wine cheese they love so much.

Next, we come to normal molds. When talking about normal molds within the home, there are really two types. Airborne mold spores, and mold growth. When it comes to the airborne type, it is simply a fact of life that there is always some degree of airborne mold spores floating around in your home. They come into the home through any gap, penetration, open door, and even on our clothes from the outside, and are considered to be normal, as long as they did not originate within the home. Normal mold growth within the home occurs on a day to day basis. It could be that “mildew” in the corners of your shower, or that weird looking black stuff you see in your window track. What makes it normal, is the fact that it is growing on a non-sustainable food source, the surface is non-porous and can typically be cleaned away with normal housecleaning methods.

Now, for the fun part, Bad mold. To put it simply, mold growth within the home is considered to be a bad thing when it is growing on a sustainable food source, and is potentially affecting the air with what would be considered “elevated” mold spores which is quite a bit different than the normal airborne mold spores we talked about earlier. The food sources within a home are pretty numerous, and can include: Drywall, wood framing, wood subflooring, debris, contents, etc… What makes this a bad thing? Well, typically when conditions such as these start to occur, the proper removal of said mold is just a bit much for the average homeowner. Not only must the impacted materials be properly removed and/or cleaned, but the airborne spores in association with the mold must be addressed as well. The proper removal of a mold problem is a very technical process, and requires the right equipment, and is just not something that the average homeowner should take on themselves.

The first step a homeowner should take when they believe they may have a mold problem is to have the conditions assessed by a Mold Investigation Specialist. Through a thorough investigation and proper testing, they will be able to tell you if you have a mold problem or not. Or, if you really prefer the terminology, if it’s good mold or bad mold.

Brandon Apple

by Brandon Apple, Mold Inspection Sciences

March 21, 2012 at 2:20 pm 1 comment

Proper Mold Assessment and Removal Process

Mold within your home is typically considered to be…, you guessed it, a bad thing. Molds can begin to grow in a number of different ways, and can grow on many different things. When a mold problem is found, the safest and most effective way of addressing the issue is with a three step process including: 1) initial mold assessment, 2) mold removal (also known as mold remediation), and 3) post remediation verification.

The first step is the initial mold assessment inspection. This should be performed by a certified mold inspection company, and that company should be completely independent of any mold remediation work to avoid conflict of interest. The assessment should include determining sources of moisture, determining the overall area of impact (gross contamination as well as elevated airborne mold spore contamination), assessment of the affected building materials and putting together preventative maintenance plans. All of this information should be compiled into a final written report, which should include the mold remediation recommendations.

Next, is the mold remediation.  This work should be performed by a competent, certified mold removal company. This can be a pretty in depth process depending on the area affected and materials that have been impacted, and will be unique to each situation. But, there are some basic steps that are almost always utilized including: containing the area from adjacent living spaces, installing engineering controls such as HEPA filtered negative air machines, removal of water damaged and mold impacted non-structural materials, cleaning and disinfecting of structural materials, scrubbing the air, HEPA vacuuming all surfaces, wet wiping all hard surfaces and returning all building materials to adequately dry conditions.

Lastly, a post remediation verification inspection should be done to ensure that the work has been performed properly. This inspection is typically done by the same company that performed the initial mold assessment. The inspection should be done while the remediation contractor’s containments are still in place, but before any materials have been installed. First the area must pass a visual inspection, meaning: All water damaged non-structural materials have been removed, all visible mold growth has been removed, all building materials are adequately dry and the area is visible clean. If the inspector deems that the visible remediation work was adequate, then air samples are collected within the work area to test for airborne mold spores. If the air samples are within industry clearance standards, then the mold inspection company will “pass” or “clear” the project. A final written report should then be provided to all relevant parties, verifying that the work was performed properly and effectively.

Facing a mold problem in your home can be a pretty daunting project at first. But, when the proper steps are followed, and competent professionals are utilized the process can be as low impact on you as possible. And, proper documentation of the entire process can save you a lot of headaches down the road when selling or renting a home with previous mold disclosures.

Brandon Apple

by Brandon Apple, Mold Inspection Sciences

February 23, 2012 at 12:00 am 2 comments

Ambient Air Sampling

During a proper mold investigation, ambient air sampling is a very important part of the investigation.  You can think of air sampling, as a way of telling us what we can’t see with our naked eyes.  But, before we can understand why this important, perhaps we should take a step back, and get to know mold.

Mold is an important part of our environment.  Its purpose is to break down dead, organic material.  If this didn’t happen, our world would probably be very dramatically different place. Just picture what a forest would like if every tree that had ever fallen was still there, and never went anywhere.  It would start to add up after a while, and I’m guessing it wouldn’t be a very inviting place.  So, molds purpose is to break these materials down, and therefore recycle that energy back into the environment.  To do this, mold has to find a food source and a water source.  It typically does this by releasing spores into its surrounding environment, generally through the air.  You can think of mold spores as seeds, which then spread out into the world looking for new food sources and water sources.  Once those are found, it can begin to grow, create a new mold colony and in turn break down its food source.  Therefore, continuing its existence, and completing it’s life cycle.  This is great news for the environment, when it happens outside of our home.  But when these processes begin to happen within our living spaces, it can create an unhealthy environment.

So, let’s now discuss what happens when mold is found within a home.  It needs a couple things to get started, one of which is a food source.  As we now know, that can be any dead organic material.  Unfortunately for us, this is readily available in any home.  It could be the paper backing on drywall, the wood framing used to construct the home, construction debris, even the skin cells that we leave behind in the form of dust.  Next, it needs a water source.  This can be introduced into a home of number of different ways, but the most common would typically be related to plumbing problem, and issue with the exterior of the home (bad siding, bad roofing, poor drainage) and/or poor ventilation and humidity problems.  So, if we now have a food source and a water source, mold can begin to grow.  Once mold begins to grow, it’s goal is to complete its life cycle, and part of that is to spread out and finding new food and water sources, i.e.  releasing microscopic spores into the environment.

Now that we have all of that out of the way, how can we tie it all together with air sampling.  Ambient air sampling is used to determine the type and quantities of mold spores within the air.  If we suspect there is a mold problem within a home, an ambient air sample is typically collected in the suspect area, and then compared to an outside sample (control or baseline sample) collected at that same day and time.  When we start to see spikes in the quantities and/or types of mold spores, as compared to the outside sample, we can start to relate that to suspected indoor sources of mold.  So, if I suspect there is a hidden mold source within a wall cavity, and the air sample collected in that location shows elevated spore types/concentrations as compared to my outdoor sample, it is very likely that there is an indoor mold source within that area.  We have used ambient air sampling to tell us what we can’t see, and had some fun in the process.

Brandon Apple

by Brandon Apple, Mold Inspection Sciences

February 9, 2012 at 12:21 am 1 comment

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