For many homeowners, the first thought in their mind when they consider installing a crawl space waterproofing system is, "But I don't go down there! Why on earth would I do that?"
Good question! And there's a great answer. While you probably don't think about your crawl space, and you may have never even seen your crawl space, it's part of your home. What happens to it has surprising effects the rest of your house.
Water can enter into your crawl space in three different ways: through the earth (or concrete) around your home, from a plumbing leak, or through the air entering your crawl space vents. Whether this moisture enters as humidity or as an all-out leak, a wet crawl space means a headache for you. Moisture collects in anything organic - including wood floorboards, support beams, and some types of crawl space insulation. As the wood swells and warps with moisture, there are nasty results: mold, rot, mildew, bacteria, and dust mites.
What you have beneath your house is no longer a crawl space. It's a habitat. The area is filled with humidity, mold spores, and dust mites. All too soon, mice, rats, snakes, and vermin will take up residence- living and dying in the dark, wet area beneath your home. And there's nothing more attractive to a termite colony looking for a new place to live than all that damp, rotting wood!
Ignore the monster lurking below while you can, but remember that even before your rotting floor and support beams are significantly damaged, you're already being affected. Warm air in your home exits the home through your upper levels, and crawl space air is sucked up into your home. As it's pulled up, nothing is stopping the humidity, mold spores, dust mite waste, and odors coming up with it. In the summer, your air conditioners will be working overtime to remove this humidity. During the winter months, cold air vented into the home hammer away at anything it can reach- including the water heater, hot water pipes, and heating ducts.
In a vented crawl space, insulation is a Catch-22. If you don't have crawl space insulation, then there's no line of defense keeping humid summer air and cold winter air away from your floorboards. If you do have crawl space insulation, then moisture and mold can saturate the material, weighing it down and causing it to collapse on to the floor. If it's wet or lying on the ground, what can it do for your home?
The first step to solving a crawl space moisture problem is to remove any standing water issues. Left in your home, it will add humidity to the home, encourage mold and mildew, and bring pests into the room while it stagnates. It simply has to go.
If your crawl space has pooling water at any time, a reliable cast-iron crawl space sump pump is the best option. Water can be directed to the sump pump via a drainage swale, or in some cases, a modern French drain system.
Humidity pours into your house through the crawl space vents, and the damp earth and cement around your home will soak up water like a sponge, releasing water vapor into the area. Cut this problem off at the source by sealing off all crawl space vents and installing a crawl space vapor barrier. Avoid cheap solutions- the kind of product you're looking for should be strong and durable- at least 20 mil thick. A quality crawl space vapor barrier will allow access for you and service workers without tearing your line of defense. Crawl space vapor barriers should also be flexible and resistant to punctures and tears, and a bed of gravel should be laid underneath to allow water to pass underneath.
