Retaining Walls

If you’re a homeowner in Alameda, Berkley, Oakland, El Cerrito, and Piedmont, CA.

Why Retaining Walls Fail

Older site retaining walls often start leaning over time. They generally lack wide or deep footings and the proper drainage for the long term. Moisture in the soil is often the culprit, causing pressure behind the wall, especially when there is an adjacent slope, plants and irrigation.

Properly Engineered Site Retaining Walls

We refer to walls in the yard as site walls. When properly constructed with reinforced concrete, large footings or piers, and drainage behind them to eliminate potential water pressure, these new walls will stand the test of time.

Foundation Retaining Walls

When the soil adjacent to a building is higher on one side or the other, the foundations will function as retaining walls and must be properly designed. If they are over 3’ in height they need to be engineered. The footings are generally much wider than those of a standard foundation. When the ground on one side or the other is level, the footing (base) of the new wall can be place under the adjacent surface, in this case under the driveway which was then patched over. On the inside of the new wall (which is partially underneath the building), a French drain is installed adjacent to the building at the base of the new wall with all the water directed to the street in front.

Retaining Wall with Piers

As an alternative to new walls with wide footings, and a requirement in hillside scenarios that are sloped on both sides, holes are drilled in which I beams are set in concrete. For tall walls these holes are often 10’-15’ deep.

Wood Lagging is Installed with I-Beam Walls

Pressure-Treated Wall Boards are installed between the beams- usually 4” thick. Pressure treated lumber is resistant to termites, dry rot and moisture over time. Because the drop off is over 30” on the downhill side of the new wall, a 42” minimum height guardrail system is required above. These railings need to be installed to resist substantial horizonal forces for safety purposes.

Retaining Wall Drainage

This patio wall is being built with a drainpipe and a drainage mat on the back side. This mat, called Miradrain directs water to enter it and trickle to the bottom where the pipe is located, acting like a miniature drainage system. This allows us to form the wall on one- side only and avoids the need for extensive gravel backfill behind the wall for drainage.

Failing Old Cinder Block Wall

Cinder block walls are often not reinforced, and cinder block is a weak material and is very porous. Often lacking proper footing and drainage, failure occurs, especially with taller walls as they age.

Cinder Block Wall Replacement

By install a new reinforced concrete wall with proper footings and drainage this wall can easily support the much higher soil level in the neighbor’s yard.

Decorative Wall Finishes

Stonework is sometimes installed on new walls to give them a more decorative look.

Stucco Finished New Walls

More commonly, we will install a texture coat of stucco on the new concrete, often to match the house stucco. This finish is relatively inexpensive and a major upgrade over rough concrete.

Retaining Walls Can Create New Space

By leveling spaces behind or in front of homes and installing new retaining walls level areas can be created where the spaces were previously unusable. These can be expensive projects, but for homes with little or no flat areas for recreating or sunbathing this can make a huge difference.