Crawl Space Waterproofing in Alpharetta, GA

Alpharetta homes built during the North Fulton building boom of the 1990s and 2000s used the minimum crawl space protection required by code at the time. A thin 6-mil vapor barrier on the dirt floor and open foundation vents were considered adequate. After 15 to 25 years, the barriers have torn, displaced, or degraded, and the vents admit humid air that condenses on cooler crawl space surfaces throughout the summer months.

The fill soil used to level lots in subdivisions like Windward, Broadwell Oaks, Thornberry, Cambridge, and Cogburn Station in the 30004, 30005, 30009, and 30022 zip codes has continued to settle over the decades. As the fill compacts, it pulls away from the foundation wall, creating channels that direct surface water straight to the crawl space. The original damproofing on the exterior walls was never designed to handle this concentrated water delivery.

Many Alpharetta homes have a hybrid foundation with slab on one end and crawl space on the other, built to accommodate the rolling North Fulton terrain. The transition between slab and crawl space creates a stress point where water can enter if the joint is not properly sealed, and these joints were rarely waterproofed during original construction.

Interior French Drain Along Foundation Walls

We install a perimeter French drain inside the crawl space along the walls where water enters. The drain sits in a gravel bed that captures water at the wall-footer joint and routes it to a centrally located sump pit. For Alpharetta homes with partial crawl spaces, we size the drain system to the actual crawl space footprint rather than a standard full-perimeter install.

Slab-to-Crawl Transition Sealing

Where the crawl space meets a slab section in hybrid Alpharetta homes, we seal the transition joint with hydraulic cement and apply a flexible membrane that accommodates minor movement. This prevents water from migrating between the two foundation types through the unsealed joint that builders left during original construction.

Sump Pump with HOA-Compliant Discharge

The sump pump collects water from the perimeter drain and discharges it through a line that exits at grade level. For Alpharetta HOA communities, we route the discharge to comply with community drainage requirements, avoiding discharge onto sidewalks, common areas, or neighboring properties. Battery backup is included for storm-driven power outages.

20-Mil Vapor Barrier Replacement

We remove the old builder-grade barrier and install a 20-mil reinforced liner across the floor and up the walls. This is over three times thicker than the original 6-mil plastic and is sealed at every seam, pier, and penetration. The difference in moisture blocking performance is dramatic and immediate.