When it comes to reducing the stack effect, there’s really only one thing that will cut the stack effect off at the source. You need to encapsulate your crawl space. After all, if there’s nowhere for air to come into the crawl space, you can’t have the stack effect in the first place. This is the process a crawl space expert will use to encapsulate the crawl space.
Remove Standing Water and Fix Leaks
First up is the process of removing any standing groundwater in the crawl space and any places water might be leaking into the crawl space. Standing water is a terrible thing to have in your crawl space because you’re inevitably going to have extremely high levels of moisture as the water evaporates into the air.
Leaks are the most common reason you might have standing water in your crawl space, but they’re far from the only reason. You might have standing water in the crawl space because your crawl space isn’t graded correctly, because of open crawl space vents, or many other possible causes. Fixing the leaks should be the first thing you do in your crawl space to avoid this exact problem.
Close Crawl Space Vents and Doors
After you’ve removed the standing water in the basement, it’s time to close the crawl space vents and make sure all the doors have effective seals. If there’s no way for air to move into the crawl space from the outside, you won’t have to deal with the stack effect at all. That means the best way to avoid issues that often arise from the stack effect is to close off the crawl space vents and install additional insulation to ensure there’s no way for air to move in.
There are a number of ways to seal crawl space vents and doors to make your crawl space function more effectively. Typically, that means adding crawl space vent covers to any open vents you have, then either installing new doors or adding additional insulation measures to the crawl space doors you have. This can be a very involved process, and it’s important to get a crawl space expert to help.
Install a Vapor Barrier
Next, especially if you have a dirt crawl space, you need to install a vapor barrier under your home. A vapor barrier does what it sounds like: It forms a barrier against water vapor. When you have a dirt crawl space, water vapor is inevitably going to rise through it. This is the case even if the top layer of the dirt seems dry. Dirt crawl spaces connect to the earth far underneath the crawl space, which retains moisture even if the rest of the dirt is fully dry.
However, a high-quality vapor barrier ensures the crawl space stays dry even if the dirt is completely soaked through with moisture. When you have a suitable vapor barrier, you no longer have to worry about any water vapor coming in through the crawl space floor. JES only uses the 20-mil CrawlSeal™ vapor barrier. Although these are thicker than the traditional vapor barrier thickness, JES uses them because of the idea that the crawl space should be overly protected rather than under-protected.
Add a Crawl Space Dehumidifier
The last step is usually to add a crawl space dehumidifier. Even if you’ve completely blocked off the entrances for crawl space humidity, that doesn’t necessarily mean your crawl space will stay at a healthy humidity level. Some locations just have naturally high levels of humidity. Those naturally high levels of humidity will still have a significant impact on your crawl space, which is why it’s important to adjust them.
Instead of just allowing the crawl space to become heavily moisture-laden, you might want to install a crawl space dehumidifier. A dehumidifier allows you to keep the crawl space at a certain relative humidity, which you can keep to a healthy level. Although this isn’t necessary for everyone, it’s useful if you want to maximize your crawl space health.