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Crawlspace Encapsulation vs. Pest Control
Crawl Space Encapsulation vs. Pest Control
~ By Jesse Waltz, Professional Engineer
From the point of view of a professional engineer, like it or not, your crawlspace is a part of your house.
For years many pest control companies have been treating crawlspaces for termites and dismissed problems like heat loss, mold, structural damage, damage to heating/air conditioning duct work, insulation, moisture issues, condensation, and energy loss. We inspect thousands of crawlspaces each year and most are covered by a termite warranty, yet very few of them address these problems.
Building scientists have written many articles on the benefits of a properly encapsulated crawlspace, which include mold and moisture control and minimizing the risk of an insect infestation. "Many termite companies lack a suitable solution to address these serious problems so they are forced to deny the need for encapsulation. " Many termite companies lack a suitable solution to address these serious problems so they are forced to deny the need for encapsulation.
This leaves customers feeling frustrated that they paid for termite inspections for years with companies that they trusted, to then find that the same companies have allowed these conditions to not only continue to exist but in fact worsen. Many customers that had a termite warranty, myself included, experienced having their warranty voided because of excess crawl space moisture.
As a homeowner and consumer, I recently purchased a new home and during inspection noticed there was termite damage. When a few termite companies 
came to my home they stated that the termite warranty on the home was void due to excessive moisture. Then two out of the three companies that inspected my home even offered me a form of crawlspace encapsulation.
Ask any termite professional which a termite prefers, wet or dry wood. The answer will invariably be wet wood. So it's in the best interest of the homeowner to keep their crawl space dry and eliminate pests. Which is why some of these pest control companies are getting into the crawl space encapsulation business.
The reason we encapsulate a crawlspace is to lower moisture levels to prevent mold, condensation, and structural deterioration of framing members. Which ironically is what invites termites and pests into your crawlspace in the first place.
There are four ways that moisture enters your crawlspace:
1. Ground water infiltration
2. Water seepage through porous block or brick walls, or foundation cracks
3. Hot humid air entering through crawlspace vents or loose doors
4. Water vapor from the exposed dirt floor
Encapsulation addresses all four of these issues by installing a drainage systems for ground water, wall liners to address wall seepage, seal off vents to prevent the entrance of hot humid air, and treat all existing air to maintain acceptable humidity levels so mold can't grow.
Recent studies have shown that closed crawl spaces should be built to minimize the entry of outdoor air into the crawl space. Specifically foundation wall vents, and wall openings to ventilated porch foundations allow entry of humid air into the crawl space, which raises relative humidity and provides the perfect breeding ground for mold.
I would be hard pressed to find any legitimate termite company that would not agree that it is better to have a dry crawlspace than a wet one. "I would be hard pressed to find any legitimate termite company that would not agree that it is better to have a dry crawlspace than a wet one.. "We understand this may have impacted their business but feel as though the homeowner has a much safer and healthier home with the installation of a Cleanspace Encapsulation system.
It's important to note that the air that is in your crawl space is also cycled through your home. This movement of air is called the Stack Effect, so if you have mold in your crawl space, you're breathing it in.
Building scientists and professional engineers, such as myself, feel that since 50% of the air you breathe in your house comes from your crawlspace that encapsulation will save you money on energy bills, prevent mold growth, prevent further wood rot, and ensure that the crawl space air that cycles through your home is healthier and safer to breath.
When JES installs the Cleanspace Encapulation System we make sure that there's a 3-inch gap from the bottom of the wooden sill to allow for termite inspection. This eliminates the discussion that termite inspection and encapsulations can not coexist in your crawlspace.
It's easy to be confused by the two-sided discussion. Please feel free to call JES with your questions, we'll provide you with the Crawl Space Science, a book on the scientific reasons behind crawl space encapsulation. We'd also be happy to show you what a crawl space encapsulation system looks like and how it works.
References:
AdvancedEnergy.org. A Quick Reference on Closed Crawl Spaces. http://www.advancedenergy.org/buildings/knowledge_library/crawl_spaces/
pdfs/Closed%20Crawl%20Spaces_Quick%20Reference.pdf
Dastur, Cyrus and Davis, Bruce. Double Duty. PCT Magazine. October 2004. http://www.advancedenergy.org/buildings/knowledge_library/crawl_spaces/
