The Salt Line in Sonoma County: How Coastal Air Affects Property Maintenance in Petaluma and Nearby Areas If you own or manage a home, rental property, or commercial building in Petaluma or elsewhere in Sonoma County, understanding the salt line can help you protect your property and reduce long-term maintenance costs. Salt air, marine fog, and coastal moisture can all accelerate wear on exterior surfaces, especially on windows, siding, paint, metal fixtures, decks, and concr