Posts tagged ‘mold testing’

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

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

Why You Need a Mold Inspection – Part I

Why you need a mold inspection

One of the most common questions our offices receive is “Why do I need a mold inspection?  Won’t mold sampling and testing tell me what I need?”  From our experiences over the last 10 years, which includes tens of thousands of mold inspection projects across five states, we consider the mold inspection to account for about 75% of the puzzle and mold sampling and testing to account for the other 25%.

Both parts are important, but they must be done in tandem — you can’t just count on one to tell the entire story.

Rather than write abstractly about why you need both an inspection and testing, I thought it would be more useful to provide a number of examples to make my case.  This posting will be the first of several hypothetical case studies I’ll present.

Our client, Mr. Brown, is in contract to purchase a new home.  He wants to make sure that he has no water intrusion or mold problems that could cost him money to repair or that would cause his family health problems.  But, Mr. Brown is concerned about the cost of the inspection and the testing.  He believes his home inspector will do a thorough inspection, so he just wants mold testing in a few rooms and wants to skip the mold inspection.  We warn him against this decision and try to explain the need for the mold inspection, but he won’t be swayed.

He asks us to collect air samples in a few rooms in the home; including the master bathroom and master bedroom.  All of the air samples come back from the lab as “normal”.  Mr. Brown purchases the home and believes everything is ok from a water and mold standpoint.  About a month after moving in, he notices a really musty odor in his master bedroom and is seeing some swelling of the drywall adjacent to the master bathroom shower.  He hires a plumber to investigate.  The plumber opens up the access panel to the shower plumbing and finds the inside of the wall full of mold.  Mr. Brown is upset because he had mold testing performed in both the bedroom and bathroom and the air samples were normal.  How could this happen?

A proper mold investigation requires both a mold inspection and mold testing.  Had Mr. Brown paid for the mold inspection, the inspector would have used their moisture meter around all plumbing areas and places where water and mold are often found — like the areas adjacent to the shower.  The inspector would have found elevated moisture and would have observed the staining and swelling of the drywall.  The inspector would have recommended a wall cavity sample or invasive testing or both.  The mold inspection service would have uncovered the mold problem.

Now, Mr. Brown is faced with a very expensive mold remediation project and repair of the drywall and shower.  Since he has already purchased the home, he will likely have to pay for it himself.  Had he spent just a little more money for the mold inspection during his due diligence, the responsibility to repair the shower and pay for the mold remediation would have been the seller’s.

That said, Mr. Brown did pay for mold testing of the air in the master bathroom and bedroom.  How were those samples “normal”?  The mold growth had an active source of water and food.  Thus, it was not actively sporulating.  And, it was trapped inside a wall cavity.  Under these conditions, it is perfectly normal to have an air sample with no elevated spore counts in the air even though there is active mold growth in the area.

Again, this is why you need both a mold inspection — a big part of which is a moisture intrusion investigation — and mold testing.

Michael Bains

by Michael Bains, President, Mold Inspection Sciences

February 22, 2012 at 5:00 pm

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