In this section, we present a brief history and background of those subjects, which comprise the basic components of Virginia waterproofing and foundation repair industry: basements, cellars, crawlspaces, drain systems, and the building materials used to build your home and foundation. We start with Basements, Cellars, and Crawl Spaces, and continue with a brief history of Basement Waterproofing. We then conclude with the most important building material – concrete. Concrete is the major component of your foundation and basement, and through understanding the properties and characteristics of this material, you will better understand Virginia basements, and their inherent problems.
A basement is defined as the lowest story of a building, either partly or entirely below grade. The first below surface foundations, i.e. – footings, foundation and load bearing walls – were cellars or crawl spaces, traditionally designed and built a minimum of 30-36 inches (or more) below the surface of land where you have winters or cold seasons or freezing temperatures, plus soil that will support a below grade structure. The frost or freezing line in the Northeast U.S. for example is 3 feet or more which is why most crawl spaces have a height of 3 feet. The frost line in some of the Southern Provinces of Canada is 4 feet.
At some point in our past, before we had electricity and refrigerators, we used to be an agricultural society. Cellars, crawl spaces, and the like were used to store foods, coal, roots, wine, grains, and other staples upon which families could depend in the seasons, like winter, when nothing was growing, and you had to live off of what was harvested in the warmer seasons, like summer and fall.
Then we discovered (like Henry French, in 1850) that these living environments, due to the high moisture content, also supported growth of mold, mildew and dampness, and other microbiology dangerous to our health, plus the proliferation of insects such as cockroaches, spiders, etc, and other insects and rodents which are also dangerous to health.
Virginia Civil engineers and homebuilders, in the mid to late 19th Century and early 20th Century, began to experiment with moisture barriers, vapor barriers, and drainage systems, using the building materials available at that time, such as terra cotta, tarpaper, and gravel.
Then we evolved into an industrial society in the late 1800′s (early 1900′s), along came electricity and appliances, and living space in the city became more important than storage space. Crawl spaces were dug-out (or dug down) to take advantage of this enclosed space already in existence, which could support more living space. Beginning with the development of large, mid-priced suburban homes in the 1950s, the basement, as a space in its own right, gradually took hold. Initially, it was typically a large, concrete-floored space, accessed by indoor stairs, and with exposed columns and beams along the walls and ceilings, or sometimes, walls of poured concrete or concrete cinder block.
A cellar is a type of basement, primarily used for the storage of food and drink for use throughout the year. Cellars are intended to remain at a constant cool (not freezing) temperature all year round and are more common in older houses than in modern homes. Usually with a concrete floor, in the 20th Century, cellars served as shelters from the possibility of air raids and missile strikes during World War II and the Cuban Missile Crisis. In parts of the U.S. that are prone to tornadoes, cellars still serve as shelter in the event of a direct hit on the house from a tornado or other storm damage caused by strong winds.
Except for Britain, Australia, and New Zealand, cellars are popular in most western countries. The majority of continental Europeans have cellars. In North America, cellars usually are found in rural or older homes on the coasts and in the South. However, full basements are commonplace in new houses in the US Northeast and other areas requiring foundations below the frost line.
The primary purpose of a crawlspace is to allow easy access to plumbing, electrical and other such maintenance, repair, and installation needs. In essence, a crawlspace, as its name implies, is a variation of a basement in which one crawls around. Some are as small as a foot in height, while others tend to be 3′ to 4′ in height. Although we occasionally encounter a concrete floor, the floor surface is commonly just dirt, sometimes with a thin piece of plastic on top, which is supposed to act as a vapor barrier.
Crawl spaces in Northern Virginia offer a practical and efficient way to access pipes, substructures and a variety of other areas that may otherwise be difficult or expensive to reach. While a crawlspace cannot be used as living space, it can be used as storage, often for infrequently used items. However, care must be taken in doing so, as water from the damp earth, humidity entering from crawlspace vents, and moisture seeping through porous concrete walls and block creates the perfect environment for mold, mildew to form on any surface, especially organic materials such as cardboard boxes, the wood under the first floor, drywall, some types of insulation, etc. Health and safety issues are major concerns and must be considered when installing a crawl space. (See Crawl Space Waterproofing)