A crawl space is basically a basement that you can’t stand up in, an unfinished space common to a home’s foundation that is usually between one foot and three feet high. Many people use their crawl spaces for storage of infrequently used belongings – holiday decorations, lawn and garden equipment and other seasonal stuff; some don’t use them at all.
It’s obvious that a crawl space used for storage must be waterproof to prevent damage to the stored goods. This extra storage space is invaluable in many homes and can be used with confidence once it has been properly waterproofed and a poured concrete floor or encapsulation system has been installed.
However, not every family needs that much storage and often the crawl space just isn’t very accessible. In either case, the crawl space goes unused but that doesn’t mean you can afford to ignore it.
Potential Problems of Unused Crawl Spaces
The biggest cause of problems resulting from an unsealed crawl space is dampness. With the typical bare dirt or gravel floor found in almost all crawl spaces, there is nothing to prevent the seepage of ground water up through the floor because of hydrostatic pressure in the underlying earth. Water may also enter the crawl space in the same ways it seeps into any basement — through cracks and over the top of the foundation.
OK, so the crawl space is leaky. What’s the harm in that? Well, the crawl space is part of your home and, even if you don’t use it, conditions there can affect the rest of your home’s living space. For example:
Moisture Vapor Rises: If the crawl space is damp, you can be sure that the moisture will eventually rise up through the floor structure and into the rooms directly above. This will increase humidity in your living space, which will make air conditioners and dehumidifiers work harder — and more expensively!
Flooring Can Be Damaged: Rising moisture will also affect flooring materials in rooms above the crawl space. Solid or engineered wood floors, along with the popular laminate floors, are likely to expand and buckle from excess moisture coming through the subfloor. Such moisture can also cause flooring adhesives to fail and vinyl or carpet tiles to come loose.
Mold Spores Grow and Spread: A damp crawl space is also a breeding ground for mold and mildew on floor joists, subfloors and insulation. A phenomenon known as the “stack effect,” where warming air in the house above causes cooler air to be pulled upward from the crawl space, may spread mold spores throughout your home.
Resale Value Diminishes: The average American moves 11.7 times in their lifetime so you’re probably going to sell your house someday. When a potential buyer’s home inspector shows up, chances are that your leaky crawl space is going to figure prominently in his report – and not in a good way.
So, How Do I Fix It?
Seepage problems in a crawl space can be repaired by many of the same methods used in a full basement.
- Cracks in poured concrete walls can be filled by urethane injection
- Exterior waterproofing membranes can be applied to foundation walls
- Interior drain tile can be installed, with or without a concrete floor
Speaking of a concrete floor, if you reconsider using your crawl space for storage, a 2”– 3” concrete floor will help prevent dampness and provide a solid, dry surface for your use.
There is one other method that is unique to crawl spaces – encapsulation. To encapsulate a crawl space, a heavy plastic vapor barrier is laid on the floor and extended up the walls of the crawl space to the top of the foundation.
U.S. Waterproofing has developed a crawl space encapsulation system called ComfortCrawl™ that includes a heavy duty, reinforced polyethylene vapor barrier applied to the floor; the walls are covered with radiant reflective insulation to lower energy costs and retard mold growth. All seams are then sealed to complete the encapsulation.
As you can see, the crawl space is an important part of your home, even if you’re not using it, and should be protected from water seepage to avoid serious problems that may affect your family’s health. U.S. Waterproofing has been keeping basements and crawl spaces dry for more than 55 years and we can certainly come up with a solution to your problem. Feel free to ask for our advice.