Vapor Barrier Installation in Aromas, CA

Local Context

Aromas Crawl Spaces Take On Water From December Through March and Give It Back All Summer

A crawl space with bare soil under it works like a moisture pump. Aromas takes its rain between December and March, and on the lower ground toward the Pajaro River bottom the water table rises with it. That moisture does not stay in the dirt. It evaporates upward into the sub-area and condenses on joists, subfloor, and ductwork. Then the marine layer comes through the Pajaro Gap on summer mornings and holds the humidity high enough that the space never fully dries between wet seasons.

What that produces is a short list, and every item on it is expensive. Wood-decay fungus in the subfloor and joists. Soft sill plates. Rusting duct straps and sagging batts. And subterranean termites (Reticulitermes spp.), which forage toward moisture and read a damp crawl space as an invitation. It is also why so many Aromas WDO reports carry Section 2 findings for excessive moisture and inadequate sub-area ventilation. Those findings do not go away when the rain stops — they come back every winter until the soil is covered.

The raised-floor construction common in the ranch-era housing here is what puts so many properties in this position in the first place. A slab house does not have the problem. A great many Aromas houses are not slab houses.