Slide 47 of 67
- Adequate ventilation is one of the best ways to minimize potential wood decay in the crawl space.
- The crawl space may be mechanically ventilated
- If not, the UBC requires 1 square foot of vent openings in the cripple walls for every 150 square feet of under-floor area.
- To provide cross ventilation: Spaced openings evenly on at least two sides of the crawl space.
- New sheathing should not reduce or cover existing ventilation openings.
- Additional ventilation should be added when wood decay is present under prevailing conditions.
- Photo shows proper crawl space ventilation needed to prevent wood rot
- If none is present, or it is inadequate, contractor must add ventilation