A crawl space is a vacant unfinished, small area in a residential building, often between the first and second floors. The term ‘crawl space’ is frequently used but rarely explained in residential construction. The word ‘crawl space’ is derived from the engineering usage of the term ‘dormatory’. The word ‘crawl space’ is used for many different purposes in the building environment, and is used as a descriptive expression for many different types of space.
A crawl space has the potential to store a great deal of heat and moisture. These areas are designed with minimum energy efficiency in mind. Even if they are designed with efficient heating and cooling in mind, they may still trap excess moisture causing increased structural humidity. Crawl spaces can be an important health risk. Moisture can contribute to the growth of mould and mildew, which is known to cause a number of health problems.
The longer a structure sits unheated or is constantly exposed to water (whether it is from a pipe break or other water leakage), the greater the chances of mold growth becoming established. A few signs of mold growth include discoloured, crumbly paint, cracked and peeling walls, dampness on the floor and ceiling and structural damage beneath the foundation. If you find any of these signs in your crawl space, it is important to act quickly to repair the problem as a mold infestation could result in severe structural damage to the building. In fact, even the smallest amounts of mould can bring down a property’s value.
Although it may seem obvious, the best way to combat mold and mildew growth in a crawl space (a room that has no central heating and air conditioning ducts) is through ventilation. By eliminating the humid air (which breeds mould and mildew) and providing a source of dry air, you will not only kill or remove the existing mould, you will prevent the new ones from growing. There are a number of ways to ventilate a crawl space including opening windows and opening doors. The most effective ventilation method for a crawl space however, is via a high efficiency particulate air (HEPA).
High Efficiency Particulate Air (HEPA) strips can be installed in any room in your home, with the one obvious exception being the crawl space. In a crawl space, they must be installed under the concrete slab. These strips are attached to a plastic tube that is connected to the outside of the slab. Once installed, the strip directs air from the inside of the house to the strip, which then directs air back to the house. This air is completely fresh and dust free.
In a cold climate, it is less expensive to ventilate a crawl space than it is to maintain a damp basement. Even if you have to spend slightly more on heating and cooling, the additional expense is not worth it. In extreme cases, damp basements cost more to maintain than a dry basement because of the additional time and effort spent on dehumidification. Another benefit of ventilating a crawl space (even if you use conventional means) is that the home’s energy rating improves. The crawl space houses the equivalent of about 8 square feet of unheated air in a home that has a conventional chimney. In climates where the temperature outside exceeds that needed for human comfort, this is significant savings.