Crawlspace Cleanup

Mold on crawlspace framing

What happens when moisture enters a dirty, poorly ventilated place that no one ever checks? Sometimes, mold.  Though fairly uncommon, mold growth in the crawl space is unusually problematic due to the effect it can have on the indoor air quality in the space above.  By most estimates, 30-40% of the air in your home comes directly from the crawl space.

Crawlspaces – A Primer.

Most houses built in the Puget Sound are constructed over a ventilated crawlspace. Basements are more common in older, urban homes.  Sealed crawl spaces are typically only found on high-end, energy efficient homes.

Constructing homes with crawl spaces brings a number of benefits.  Installation of HVAC ducting and plumbing lines is much easier.  However, crawlspaces also bring their own set of  problems.  Much of these issues are due to the fact that crawlspaces operate outside the conditioned (heated) air space of the home, yet lie within the building envelope.  This means that crawlspaces exist in an in-between zone where they don’t benefit from indoor heating and ventilation, but must remain cleaner than the exterior of the building.

What are the most common sources of crawl space problems in Seattle?

  • Missing vapor barrier
  • Poor drainage / flooding
  • Broken sump pump
  • Inadequate perimeter ventilation
  • Rodent infestations
  • Saturated framing during new construction

 

Example Crawlspace Mold Remediation Report

Work #: 202026

damaged insulation in crawlspace

Project Background Information

Mold Growth:

  • No significant mold growth observed on inspection.

Insulation:

  • Crawlspace insulation installed within the belly of the manufactured home. Visible portions of insulation appear to be in adequate condition.

Moisture:

  • At the time of inspection no increased moisture content was noted in the framing or subflooring.
  • Standing water noted in portions of the crawlspace.
  • Large amounts of standing water (up to 6” deep) was noted below the vapor barrier. The foundation drainage, sump system, and crawlspace grading must be addressed to prevent future water intrusion.
Water in Crawlspace

Leaks:

  • No obvious plumbing leaks were observed on inspection of the crawl space. Environix is not a professional plumbing contractor and cannot guarantee the condition of any plumbing.

Vapor Barrier:

  • Intact- Vapor barrier is intact and provides adequate coverage to all soil.

Ventilation:

  • Current ventilation is adequate to exhaust normal amounts of humidity.

Ducting:

  • The HVAC ducting along the back side of the home is not adequately insulated allow excessive heat loss through ducting walls.
  • All HVAC ducting in unconditioned space must be well insulated.
  • The flexible crossover duct appears to be laying in standing water and should be replaced. This ducting should be replaced with rigid metal ducting, hung above the ground, sealed, and insulated.
More water in crawlspace

Trash and Debris:

  • The crawlspace is currently free from excessive amounts of trash and construction debris.