Retaining walls come in a variety of shapes and sizes, made of concrete, wood, block, and with steel beams for posts. They function to hold back soil and are often used as foundation walls.
Many older walls fail due to inadequate footings, lack of drainage behind the walls, or poor soil conditions.
We construct walls using L-shaped footings on most level surfaces, but sometimes drilled concrete piers or steel I-beams set in concrete are needed to support the new walls when they are on a slope or if soil conditions are poor.
By excavating soil in basements or in yards and building new retaining walls, we can help home owners create brand new living spaces, patios, garages, etc.
Here are some of the types of retaining wall projects we do in our service area of Oakland, Berkeley, Piedmont, and Alameda, CA:
- Retaining Wall Repair or Replacement
- Pier and Grade Beam Concrete Retaining Walls
- Wood and Pressure-Treated Retaining Walls
- Railroad Tie Retaining Walls
- Foundation Retaining walls
- Block Retaining Walls
- New Wood or Concrete Retaining Walls
Retaining Wall Repair or Replacement
Older retaining walls often fail due to inadequate supports or lack of drainage. Concrete or brick walls often have shallow conventional footings, and require L-shaped footings typical of modern retaining walls if the ground below them is level, or drilled piers if they are on a slope. The drilled piers may need to be quite deep if the walls are tall and the slope is great. This often requires a more substantial design than was originally executed to create a properly engineered wall.
Pier and Grade Beam Concrete Retaining Walls
Concrete walls built on a slope will generally require drilled concrete piers, with steel reinforcing in them which will be tied into the new concrete wall spanning between the piers. The piers can be anywhere from 4’-20’ deep or more depending on the height of the wall, the grade, and the soil conditions. If site conditions do not allow an excavator to be moved on site for the drilling, portable equipment can be used to drill the holes, which is run from a hydraulic unit that is placed on the street.
Wood and Pressure-Treated Retaining Walls
These walls are generally simpler and more cost-effective than concrete. For shorter walls (generally around 4’ or less), pressure treated wood posts (4×6) and wood wall boards (3×12 or 4×12) are feasible; whereas taller walls often require steel I-beams set in concrete as the support posts to avoid bending due to the greater soil pressures.
Railroad Tie Retaining Walls
We no longer recommend installing railroad tie walls due to the highly toxic nature of the material. We do remove them, however, replacing them with either concrete or pressure-treated walls.
Foundation Retaining Walls
When the dirt level is lower in the crawlspace or basement than the corresponding level outside, these become foundation retaining walls rather than simple “T” foundations. They are designed as L-shaped footings to prevent the greater outside soil pressures from pushing or overturning the exterior walls.
Block Retaining Walls
Cinder block retaining walls are generally a cheaper alternative to reinforced concrete. If not waterproofed properly, they will have drainage issues at the mortar joints. If not properly reinforced, they will have no structural integrity. We prefer not to install these as new walls, though we end up replacing them a lot with concrete walls.
New Wood or Concrete Retaining Walls
Both wood or concrete can be used to construct new retaining walls, and both will work fine if designed properly. The key is proper design: the depth of the materials, their sizing, and proper drainage behind the walls will yield long-lasting results.