VAPOR BARRIER INSTALLATION IN GLENDALE, CA

The Southern California climate feels dry at the surface, but the ground beneath a Glendale crawl space holds moisture year-round. The specific geology of the Verdugo foothills compounds this. The clay soils that dominate Glendale’s hillside neighborhoods are among the most moisture-retentive soil types in Southern California. These soils absorb winter rainfall and release moisture slowly over a period of months, meaning that crawl spaces in the Verdugo Hills and adjacent neighborhoods experience elevated ground moisture from winter rains continuing well into summer, even during periods of surface-level dryness.

This creates a particular problem for hillside Glendale homes. The clay soil’s seasonal moisture cycle generates more crawl space humidity than the sandy or loamy soils found in other parts of the LA area, and the original vapor barriers installed in 1950s and 1960s construction were not designed to manage this load for 60 or 70 years. Thin un-reinforced sheeting from that era is typically torn, compressed against the ground in low-clearance spaces, and provides almost no meaningful moisture control.

The older flat-lot homes near downtown Glendale and in the Adams Hill area face a different moisture profile. Ground moisture is more consistent year-round rather than seasonal, and the crawl spaces in older homes in these areas tend to have lower clearances, making inspection and maintenance difficult. Deteriorated vapor barriers in low-clearance spaces often go unnoticed for years because access is limited and the consequences arrive slowly.