If you are building a new home or renovating an existing home you may have heard of a ‘crawl space’. But what is a crawl space? A crawl space is a vacant unfinished, narrow area in a house, usually between the first and second floors. The word ‘crawl’ is derived from the Latin word ‘capuit’ meaning hand.
There are several reasons for having a ‘crawl space’. One reason is that it was originally created to give easy access to a cellar, hence the name ‘crawl’. Another reason is the construction of houses with all-sided walls, which were considered difficult at the time; in order to create a flat roof with no overhang on one side, foundations were poured below the existing walls. This is called pouring the foundation.
If the walls are poured to level the roof then you are in a position of having a foundation, but without the overhangs that provide good ventilation to a crawl space. A concrete floor provides good ventilation but does not allow much outside air to come in, unless there are large openings in the walls. The air that comes in can easily be trapped by the concrete, therefore mold and mildew can grow very quickly. It is these black or dark colored molds that mold loves. They are the perfect growing environment for mold, and it takes very little moisture to cause mold problems in a concrete slab.
If you are building a new house, make sure that you have plenty of space to add in crawl spaces underneath your finished basement walls. This can provide the perfect amount of room for expanding into a crawl space, if desired. If your house has two levels, or some rooms are on higher levels than the others, then there is no problem with putting in crawl spaces underneath your finished basements. You may choose to just use some drywall between the floors and walls as a transition from one level to another. It is not recommended to use actual brick or stone blocks in this area, just put in cinder blocks.
You will also want to look for insulation in your crawl space. The walls should have insulation applied to them, or the space could have loose, damp insulation throughout. This allows moisture to get in and does not provide good insulation. Exterior walls in the crawl space should also have insulation applied. If you are getting this type of insulation, make sure it is fairly rigid and tightly applied, because the air circulation is important.
Another issue that many people do not consider when they build their basement are the foundation footers. Often, these are not finished properly and can allow moisture and water to get underneath the finished concrete slab. Once the floor is finished, then the only real problem left is standing water on the outside of the finished floor. You may also run into problems if you do not have any kind of water control system in place for the crawl space, which allows the water to drain.