Humidity

Make sure there is plenty of ventilation in the crawlspace before using it. The sand should be used to fill any low spots in the crawlspace. Using a layer of 6 mil or thicker plastic, cover the ground beneath the entire crawlspace. Place a layer of sand on top of the plastic to keep it in place and to absorb any excess moisture. 

Does it ever become too dry in a crawl space?

The installation of a relative humidity meter in the crawlspace is recommended as good practice. The relative humidity should be kept below 70%, but not too low to prevent mold growth and other problems. Crawlspaces can become overly dry. If the moisture content of the wood is reduced from 60 percent to 5 percent, there will be significant shrinkage and cracking in the floor.

Are crawl spaces capable of increasing humidity in a home? 

Yes. On the other hand, it is actually true that open crawl space vents tend to increase rather than decrease the amount of moisture in the crawl space. By allowing cool and warm air to mix, open crawl space vents raise the relative humidity in the space, which is typically greater than 100 percent in most cases.

Must a crawl space be dried in order for it to be usable?

Fans are an incredibly effective way to dry out a space that has condensation and moisture on the walls and ceilings. Fans installed in your crawl space drainage system will aid in the thorough and rapid drying of the area and the prevention of mold growth. Make certain that a dehumidifier is in place afterward to keep the area dry.

When it comes to crawl spaces, is 70 percent humidity too high?

Please keep in mind that condensation will form on some surfaces when the relative humidity in an area reaches greater than 100 percent. The ideal humidity level for a crawl space is significantly lower than 100%. You will eventually experience condensation issues if you allow the soil to continue to pump moisture into the air for an extended period of time.

Is it permissible to use plastic sheeting as a vapor barrier in a greenhouse?

Vapor barriers are materials that prevent moisture from passing through them, such as plastic sheeting, in their most basic definition. Laying a plastic garbage bag down on some damp soil is a very simple experiment to demonstrate how a vapor barrier works.