Questions About Mold


Mold Removal Portland, OR - Before mold removal in house hallway walls


Mold, what is it and what is it good for? You actually may be surprised. We get a lot of the same questions as well as the same assumptions about mold from our customers – here’s a list of our frequently asked questions or incorrect but often assumed facts about mold…

What is mold?

Neither plant nor animal, mold is made up of asexually producing simple cell structures. Reliant upon water to sporate, and spread by air or water. Read more here.

How does mold grow?

Mold needs four elements (plus time) necessary to grow. Moisture, food (any dead organic matter like leaves, a log or even 2x4s and plywood), temperatures (usually between 55 and 90 Fahrenheit is just right) and a single mold spore.

A single mold spore can reproduce as an asexual producing simple cell. That means one mold spore becomes two mold spores, becomes four, becomes eight and so on. So not only can mold grow quickly, it’s a pretty easy recipe. Read more here.

What’s the difference between mold and mildew? 

I often hear clients say “I have some mildew but it’s not that bad.” What many people don’t realize is that mold and mildew are pretty similar. For one, they are both fungus, they both eat organic matter and both can cause harmful side effects. Basically they are moisture problems that cause fungal growth in your living or work space. What differentiates them? Mildew is usually a white or gray powdery-like coating on plants. Mold on the other hand can be a multitude of colors and grows almost exclusively on dead organic material. If you think the dark spots on your drywall or in your attic is just mildew…think again, it may just be mold.

Does the color of mold determine how dangerous it is? 

Just because mold is black, does not necessarily mean that it’s harmful and just because it’s not black, doesn’t necessarily mean that it isn’t. There are plenty of black or dark molds that are less harmful while there are green, white and other colored molds that are very harmful. Basically, color is not an indicator of how dangerous a particular mold type is. That’s why it’s best to have a remediation expert inspect your business or home to make sure you aren’t exposed to any dangerous molds.

What does mold smell like? 

Mold has no smell.  When people say they “smell mold,” what they are likely smelling is the byproducts of the decomposition due to water.  Water doesn’t rot, but when things get and stay wet, they decompose, and it is this decomposition that is causing the smell.

Are there home remedies I should try? Will bleach help?

Bleach will actually worsen a mold problem. Because bleach is over 90% water, after the chlorine evaporates, the area is left with water, which in turns helps promote mold growth! Read more here.

Other home remedies we’ve heard of are vinegar and tea tree oil but neither have been scientifically shown to effectively mitigate mold. While vinegar is a great nontoxic cleaner it has been proven to be an even less-effective solution than bleach. And Tea tree oil has historically been used to treat infestations, but there isn’t scientific evidence to show that it’s effective against fungus whatsoever.

What are common molds in Portland/Vancouver area?

The most common mold in this area, and maybe the world is Cladosporium. We also see Penicillium/Aspergillus, which is a potentially harmful mold. Aspergillum can be white or gray and can be fatal if not diagnosed properly. And the two types of toxic mold we see most often are Stachybotrys and Chaetomium. It should be noted that there are at least 26 types of Stachybotrys. Stachybotrys is black and has an oily consistency when wet.  That said, there are a multitude is mold types potentially present here in the NW, these are just the ones we see over and over again.

Why is remediating mold important? Are mold fears overblown or exaggerated?

Sometime in the late 90s and early 2000s, the term “Mold is Gold” surfaced. For the first time in history, people started to take mold and the health affects seriously, but unfortunately, this spawned an industry of questionable character. Since almost no one knew anything about mold, many mold remediators used this heightened awareness to proliferate fear, all for financial gain.

Now, that said, mold does have it’s health and building affects, and it should be treated with the proper urgency. Depending on the type of mold, if it is in your home, it is likely affecting, or will affect your health.  Read more about this toxic mold story here.

To what degree and how quickly depends on a multitude of factors such as, what type of mold is it, how much of it is there and how does the individual person being exposed react to that particular type of mold. For instance, one person might react immediately to a specific type of mold, and someone else might not exhibit any symptoms for months or years.
 When it comes to buildings, none of that really matters. Mold is doing to your building what it does to a downed tree in the forest, which is, decomposing it. That is mold’s job, decomposing dead organic material, which is a good thing, except when it’s the organic material we built our homes out of!

If mold is natural and exists in the world, why should I be concerned about mold in my house or building? What are some health and building impacts?

If I’ve said it once, I’ve said it a thousand times, mold is not some big, bad enemy. It has a very useful function in our world. Think about it, if there was nothing to break down dead organic material, we would be up to our eyeballs in downed trees, animal carcasses and any other organic material.  So mold in the natural environment is a good thing, and likely is essential for life.  However, when it sporates in the indoor environment, it is allowed to buildup to levels that are unhealthy for people and pets. What’s more, if it’s decomposing dead organic material we built our homes or buildings out of, it can become a very serious problem to the structural integrity of living and working spaces.

Can you explain some of your remediation techniques? What is containment and negative air pressure, PPE, etc.?

Containment is a vital part of any remediation. It is the physical temporary barrier that is erected to prevent mold from a contaminated environment affecting a non-contaminated environment.

Negative air pressure is the other side of the critical barrier coin. It is the virtual barrier that prevents mold escaping containment. Basically, by putting any environment under negative pressure, any airflow will be coming from the outside, and into the negatively pressured space. With air rushing in, it does not allow mold to push outside of the space.

PPE stands for Personal Protective Equipment. It is the masks, gloves, suits and respirators that remediators use to protect themselves against mold exposure.