Not only do wet climates cause an invisible stream of water vapor into a home, but groundwater also leaks into many crawl spaces. Water enters through cracks of the floor footing and the walls causing puddles to begin to form within the invaded space. Eventually these puddles will start to evaporate upward into the house. Although crawl spaces are usually made from block walls, these walls are still porous and have many mortar joints which suck up water from the ground. The puddles of water do very little to hurt the home, but the water vapor, or humidity, will harm the house.