December 17, 2012

Crawl Space Doors - Don't Cut Corners Pt. 1

crawl space doors
When it comes to installing a crawl space door, most of us don't give it too much thought. Whatever closes up your crawl space, right? 

There's more to selecting the right crawl space door than you think. Are you just covering the entrance to your crawl space or are you trying to minimize crawl space moisture? 

If you're trying to reduce the moisture in your crawl space, then you'll need to install more than a crawl space door; you'll want to invest in encapsulation. 

Why should I worry about crawl space humidity? 
An unsealed crawl space can be the lair of mold, mildew and a variety of pests. These problems thrive in high humidity environments. And chances are good that if you have an unsealed crawl space, you also have high humidity.

Open foundation vents, loose doors and dirt floors all contribute to your crawl space moisture problem. When the outside air combines with the air in your crawl space, it can add to the humidity that's already in your crawl space. 


Here's how it works: Let's say that your crawl space is 65°F, and the outside air is 95°F (with a relative humidity of 70%). That's a temperature difference of 30°F. For every degree that the air cools, the relative humidity goes up by 2.2%.

Then the different temperatures are combined, the crawl space humidity will increase by 66%. Air can only hold up to 100% humidity, after that it will need to release the excess moisture.

With the increase in humidity of 66% added to the 70% humidity of the outside air, the total humidity is 136%. The air cannot hold this much moisture and as a result you'll end up with crawl space condensation or sweat.


All of this extra crawl space moisture will contribute to the stack effect and a variety of other problems.

Want to learn more? Come back next week for part 2 of our Crawl Space Doors blog.

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