Black mold in crawlspaces

Posted by Matt Buchanan

We’re going to spend much of 2017 talking about black mold. It’s a pervasive enemy to many homes throughout the country and a serious health risk to those exposed to high levels of black mold spores. We’ve spent much of the last few years detailing water damage and the impact it has on homes. In doing so, we’ve discussed the correlation between moisture and mold. But this year we’re going to delve further into the root causes of mold damage, where you’re most likely to find it, and what you can do to either prevent it or make sure it’s safely removed in the event you discover it. So with that backdrop, let’s talk about black mold in crawlspaces.


What causes black mold damage in crawlspaces?


What causes black mold levels to become elevated in any environment are the same things, whether it’s in your kitchen cabinets or below your home or even outside in nature for that matter. To review, what mold needs to grow and expand inside a home is:

() the right temperatures

() food

() moisture

Unfortunately for us, mold is most comfortable in the same temperature range that we find comfortable, but can also thrive in considerably colder temps. And as for food, mold spores love the organic cellulose found in wood. That means the main components of your crawlspace, the floor joists and beams supporting your home, are the perfect food for toxic mold. So where does that leave us? Trying to measure and manage the one factor we can control: moisture. Here’s the main ways moisture enters your crawlspace:


crawlspace-water-poolingWater pooling in your crawlspace

Most of your crawlspace resides underground. That can be troublesome when you have a water drainage problem outside of your home. We’ve discussed at length the issues with lawn sloping and its impact on home water damage, so for the purposes of this blog post, we’re just going to point out that if you have water seeping into your foundation walls from the ground, it will end up causing big problems as it sits in your crawlspace.

In homes with crawlspaces, there is another potential cause of excess moisture: plumbing pipes. Both the supply lines and drain pipes that service your home’s plumbing systems are housed in this space. So if either develops a small leak, it can lead to a lot of water being dumped into your crawlspace.


Evaporating ground moisture

Depending on where you live (both geographically within the US as well as your proximity to a river or lake or other large deposit of water) your soil is going to naturally hold some moisture. If that is the case, that moisture can evaporate into your crawlspace.


Air from outside coming in through your vents

Your crawlspace needs to breathe. That’s why you’ll notice vents located around your home that allow air to exit your crawlspace. It also allows air to come into your crawlspace. In many cases, the air inside your crawlspace is cooler than the air outside. Cool air can’t hold as much moisture as warmer air, so the moisture trapped in the air turns to liquid as it cools in your crawlspace. Overtime, the moisture can create serious water issues that can allow for black mold growth.


How can I prevent these conditions from happening? 


If you live in a humid environment or in an area with a high water table, you are right to be concerned about moisture problems in your crawlspace. And as we’ve said on this blog a thousand times, it’s up to you to gauge the risk you are at of developing problems with the cost of implementing proactive solutions to stop those problems from happening. For some people, that calculation may determine the need for somewhat costly solutions. For others, it may simply mean that keep a more watchful eye on their crawlspace in the event a problem does arise. But below are some measures you can decide for yourself whether or not you want to take in order to prevent mold from damaging your crawlspace.


digital-thermo-hygrometerInstall a digital thermo-hygrometer

A hygrometer measures the relative humidity inside your crawlspace and can come with a a remote sensor that allows you to monitor the conditions inside your crawlspace without having to go down there yourself. If the relative humidity approaches 70%, you’ve got a critical problem on your hands that you need to address. A simple hygrometer can be had for $30 or so. If it means you’re alerted to a problem that could end up costing you several thousand dollars, in our minds $30 is worth that peace of mind.


Fix your lawn’s slope

If you notice water pooling on the exterior of one section of your crawlspace (and you don’t see any issues with plumbing pipes in the vicinity), you may have an issue with groundwater seeping into your crawlspace. Luckily, this should be a relatively cheap fix. The issue most likely is that the slope of your lawn is towards your home as opposed to away from your home. Fix this problem and it will allow any water that comes down near your foundation to be carried away from the home and into your yard and/or street. That’s a lot better than inside your crawlspace!


Install a vapor barrier

In the event you have moisture from the ground evaporating up into your crawlspace, it may be in your best interest to install a vapor barrier. A basement waterproofing company can do this for you, or it’s something relatively inexpensive and easy you can do yourself. Here’s a quick video demonstration detailing both the proper materials and techniques used to install a vapor barrier.


Hopefully this blog post helps give you a little more insight into the causes of black mold in crawlspaces as well as solutions to fix the conditions necessary to create said problems. Of course, if all of this advice is too late for you and you do have visual black mold in your crawlspace, please do give us a call. We would be happy to come out and inspect your crawlspace and help give you a better idea of the process and costs involved with removing the mold and restoring your crawlspace!


About Matt Buchanan

I grew up in Irving, TX and left for Nashville, TN for college. After college I lived in Washington, DC and then in Cairo, Egypt. After coming back to the states, I spent a couple of years back in Dallas before moving with my wife to Denver!
This entry was posted in Mold Remediation. Bookmark the permalink.

Comments are closed.

  • YouTube
  • Category

  • Recent Posts

  • Recent Comments

  • Sign Up For Our News Letter :