HIGH MOISTURE, ROT/DECAY CONDITIONS

C.  HIGH MOISTURE, ROT/DECAY CONDITIONS:
Frequently, high moisture conditions under a house (Fig. C1, Item A) can raise the moisture content of surrounding wood pieces. Fungus attack and deterioration are likely to occur (Fig. C1, Item B).  Fungus can begin to rot wood quite quickly. Once a fungus is reasonably established, the wood pieces may have to be replaced.

WARNING: Immediate efforts should be made to reduce the moisture in the area.

WHAT TO:  HOW TO:
This usually requires draining the water, collecting and discharging existing water, taking moisture out of the air with dehumidifiers and ventilation fans, and eliminating the recurrence of moisture with drainage controls.  Vapor barriers, used to control moisture rising from damp soils, are usually extended from the floor of the crawl space and up the sides of the foundation walls.  If it is expected that additional water will seep into the space, the seams of the vapor barrier are glued together to prevent water from passing through and covering the vapor barrier.  Additional vents may be required for crawl spaces that are affected by seepage.  It is important that the vents be adequately sized, located, and screened.

WARNING:  Vapor barrier should not be laid into contact with wood support members since this may lead to continuous wetting (and potential rotting).

Adding vents can lead to freezing pipes (Fig. C1, Item C).  Make certain that pipes are protected from freezing.  Crawl spaces that can get wet or damp should not have their vents blocked or closed during the winter.

There are vents available that will automatically open and close according to outside temperature.  These can prove to be very destructive under certain conditions.

Occasionally the cavities of foundation wall blocks are injected with foam to lessen the transpiration rise of contained moisture.  For additional information see structural section “h”. A reasonably instructed homeowner, or handyman, should be able to accomplish these modifications.

Always consult with an architect, building analyst, or professional engineer when contemplating installations of this sort.