Crawl Space Moisture

In the Seattle region, many homes are built with an area of unconditioned space between the floor and the ground.  This is generally referred to as a “crawl space”.  Although, most home owners do not routinely inspect the crawl space unless there is a problem, it is useful to understand how the conditions in the crawl space can affect the structure and durability of the home.

Moisture in soil causing mold growth.

Moisture in soil causing mold growth.

Symptoms of increased moisture in your crawl space can take many forms.  Often, the problem presents itself as unexplained musty odors in the home.  These odors may be the result of mold and mildew growth,  or simply normal soil smells that are finding their way into the living space.  These odors may be the only signs that a typical home owner will notice, but it is useful to have an inspection performed by a qualified professional to make sure that other more serious problems are not occurring.

Where does crawl space moisture come from in Seattle?

  • Evaporation from soil due to inadequate of inappropriately installed vapor barrier.
    Water seepage through foundation wall

    Water seepage through foundation wall

  • Intrusion from faulty downspouts or exterior drainage.
  • Intrusion from underground springs.
  • Leaky plumbing, or water damage that has occurred inside the home.

Why is crawl space moisture a problem?

Crawl space moisture can lead to mold growth, structural damage to building framing, increased odors, and the attraction of pests.  Termites and carpenter ants may be attracted to moist lumber, and cause significant damage to the building resulting in thousands of dollars of damage.

What can we do to limit crawl space moisture in our Seattle home?

  • Re-direct gutters and downspouts to drain away from the foundation.
  • Make sure that exterior drainage is adequate.
  • Install sump-pump with appropriate drainage when water intrusion cannot be stopped at the source.
  • Ensure that vapor barrier is installed correctly, and in good condition.
  • Install depressurization fans to vent excess humidity is habitually damp crawl spaces.
  • Visit our page on crawl space moisture removal

Also, for more information, visit Energy Savers