Project Description

New Foundation – Mill Valley

Completed projectCompleted project

Completed project

Excavating the basementExcavating the basement

Excavating the basement

Excavating the garage

Temporary shoring at basement

Drilled shafts for tiebacks

Temporary shotcrete wall at garage upper lift

Soil Nails and Shotcrete holds Excavated Soil

Reinforcing steel for permanent wall

Waterproofing membrane in the background

Shotcrete placement for permanent wall

Building forms for the concrete garage roof

Formwork for garage door opening

View of garage roof and concrete elevator shaft from above

Garage roof with electrical distribution prepared for concrete placement

Structural slab with moisture barrier and underground electrical conduits

Concrete garage roof

Structural slab with moisture barrier and underground electrical conduits

Hillside foundation for a Mill Valley home

The Challenge: The foundation and garage construction for this Mill Valley home required deep excavation into a steep hillside. The garage was designed to have a rooftop garden and an elevator leading up to the house. The hillside was rocky, so excavation would be particularly difficult. Additionally, the hillside had to be effectively shored and an underground springs continuously dewatered during the excavation and foundation construction operations.

Our Solution: We retained an engineering firm to produce a shoring design for this project. We shored the hill in 8’ lifts utilizing tiebacks and reinforced shotcrete.

With the assurance that the excavated area was totally stable,we began constructing the permanent foundation and retaining walls. During the course of the construction, we placed an advanced waterproof membrane, gravel and a sophisticated drainage system between the temporary shoring and the garage walls to enable water from the underground spring and rain to drain properly. The waterproof membrane and the drainage system would safeguard the concrete walls against water infiltration into the garage, basement and elevator shaft and eventual corrosion of the concrete.

Once the garage and its concrete roof were completed, we built terrace walls on the roof of the garage with its own waterproofing and drainage system. At the end of the project, the hillside was completely reconstructed above the garage and planted.

To learn more about how we can help with yournew foundation project, please contact concrete contractors SteelCore Builders at: 415-331-0525.