Foundation Drainage, Waterproofing and Seismic Retrofit Project in Orinda, CA
Location: Orinda, CA
Problems: Water collecting along the rear foundation wall and the need for additional seismic reinforcement beneath the home
Services: Foundation drainage, foundation waterproofing, sump pump installation, seismic retrofit and cripple wall strengthening
Solution: Installed a new perimeter drainage system with foundation waterproofing and a sump pump, then strengthened the home’s foundation with anchor bolts, plywood shear panels, foundation straps and framing hardware.
The Problem: Water Management and Structural Reinforcement
Many hillside homes in Orinda require attention to both drainage and structural performance. Water collecting alongside the foundation can place additional stress on below-grade walls, while older homes may also benefit from seismic upgrades that strengthen the connection between the framing and foundation.
For this home, Ward Construction developed a repair plan that addressed both concerns during the same project. The work focused on improving water management behind the home while also increasing the home’s resistance to earthquake forces through a comprehensive seismic retrofit.
The Solution: Installing a New Foundation Drainage System
Ward Construction constructed a 27-foot drainage system along the rear of the garage and home.
The drainage system consisted of two separate pipes installed within a rock-filled trench. A perforated pipe was designed to collect groundwater moving through the surrounding soil, while a second solid pipe carried roof runoff from the home’s downspouts.
Collected water was directed into a new sump basin, where it could be pumped into the property’s existing patio drain for safe discharge away from the foundation.
Waterproofing the Foundation
Excavating alongside the foundation also created the opportunity to improve moisture protection.
Ward Construction waterproofed the exposed foundation walls with two coats of asphalt emulsion reinforced with fiberglass mesh before backfilling the trench. Combining waterproofing with foundation drainage provides two complementary layers of protection by reducing the amount of water reaching the foundation while also creating a barrier against moisture that does contact the wall.
Building a Drainage System for Long-Term Performance
The drainage system was constructed using methods intended to provide reliable long-term performance.
The perforated drain pipe was installed below the level of the garage slab, pitched toward the sump basin, and placed on a bed of clean gravel with the perforations facing downward. The trench was backfilled with clean drain rock inside a 12-inch-wide trench, providing generous drainage around the pipe. A clean-out was also installed so the system can be inspected or cleaned in the future if necessary.
Strengthening the Home for Earthquakes
In addition to improving drainage, the project included a comprehensive seismic retrofit beneath the home.
Ward Construction installed:
- Thirty-five epoxy-set anchor bolts
- Twenty Simpson UFRP foundation straps
- Approximately 80 linear feet of half-inch plywood shear panels along the inside face of the existing cripple walls
- New framing clips connecting the floor joists to the shear panels
Together, these upgrades strengthen the connection between the home’s framing and foundation while improving the cripple walls’ ability to resist lateral movement during an earthquake
Why Combine Drainage and Seismic Improvements?
Many homeowners think of drainage and earthquake retrofits as unrelated projects, but both involve work around the home’s foundation and crawl space.
Completing these improvements together can reduce disruption, improve access to structural components and provide a more comprehensive upgrade to the home’s long-term performance. For this Orinda property, the project addressed moisture management, foundation protection and seismic strengthening as one coordinated solution.
The proposal also recommended a floor level survey if the homeowner wished to further evaluate foundation settlement, demonstrating Ward Construction’s emphasis on measuring existing conditions before recommending structural repairs.
Need Foundation Drainage or a Seismic Retrofit in Orinda?
If you’ve noticed water collecting around your foundation, damp crawl spaces, or you’re considering an earthquake retrofit for an older home, it’s worth evaluating whether both issues can be addressed during the same project.
Ward Construction specializes in foundation drainage, waterproofing, sump pump installation, seismic retrofits, foundation bolting and cripple wall strengthening throughout Orinda and the East Bay. Every repair is designed around the property’s drainage patterns, structural condition and long-term performance goals.