He Bolted Steel Posts to His Driveway and Built a Retaining Wall With 6×6 Timbers
A steep exposed bank ran beside the driveway, leaving soil and roots above the concrete with no barrier between the slope and the usable space below. Instead of building a block wall or setting wood posts into the ground, Reddit user u/Mrcraigt designed a retaining wall around steel uprights anchored to the existing concrete.
The homeowner had the steel supports fabricated by a local welder, then paired them with ground-contact pressure-treated 6×6 timbers. The finished wall follows the base of the hillside and ends in gravel-filled steps, adding access to ground that had been cut away when the house was built in 1952.
Exposed Hillside Met the Driveway With No Retaining Wall
The concrete driveway extends to the base of a steep bank between the brick house and storage structure. Soil sits above the slab, with exposed roots and loose material visible across the cut face.
According to the homeowner, the hillside dates to the home’s construction in 1952 rather than recent excavation. The project focuses on the lower edge, where a wall can separate the driveway from the bank without taking much space from the concrete.
Loose Soil Reached the Concrete Along the Full Bank
A closer view shows how little separation existed between the slope and driveway. Rocks, soil, roots, and debris reached the slab, while the bank changed height across its length.
That narrow strip left little room for a thick wall system. The new structure needed to sit close to the slope while preserving the open concrete area in front.
Steel Uprights Created the Wall Structure
Instead of digging post holes beside the driveway, the homeowner had steel uprights fabricated to support the timber wall. Each support uses a vertical steel channel connected to a horizontal foot resting on the concrete.
He drilled 5/8-inch holes into the six-inch slab and used two expansion anchors per upright. The homeowner said drilling eight holes and securing the supports took less than an hour.
Steel Channels Were Sized Around 6×6 Timbers
The wall was designed around 6x6x8-foot pressure-treated timbers, which measure about 5.5 inches across. The homeowner asked the steel supplier for an I-beam profile with an interior measurement close to the timber width.
The fit still required adjustment. He removed about a quarter inch from the timbers with a cordless hand planer so the wood could slide into the steel channels.
First Timber Rows Set the Wall Line
With the steel fixed to the slab, the first timbers establish a straight boundary along the hillside. The uprights divide the long wall into sections and hold the boards against pressure from the fill behind them.
Eight-inch TimberLOK screws connect the wood members. The homeowner also coated the backs of the ground-contact pressure-treated timbers with asphalt fence-post sealant before placing them against the bank.
Stacked Timbers Filled the Space Between Steel Supports
Additional timber courses turn the open steel framework into a continuous retaining face. Narrow steel uprights remain exposed on the driveway side, breaking up the long run without requiring wide masonry columns.
A 2×8 board caps the top of the wall. The homeowner reported that the straight section took about four hours to build, including drilling the concrete and installing the uprights.
Finished Wall Preserved the Concrete Driveway
The completed straight section creates a defined edge without pushing far into the slab. Wood spans most of the visible face, while the steel supports handle the connection to the concrete.
Behind the wall, decomposed granite fills the retained area. The homeowner did not install a dedicated drain behind the structure, noting that the property is in the Mountain West, the soil test showed decomposed granite with 15% clay, and water can exit beneath the bottom beam because the slab slopes away from the hill.
Wall Ends in Gravel-Filled Steps
Rather than stop the retaining wall at the house, the homeowner used the end of the structure to create steps leading toward the higher ground. Thick timber borders form angled treads filled with compacted gravel.
The geometry changes at each level to connect the driveway elevation with the path beside the house. This portion took three partial days because the homeowner worked out the stair design during construction.
Timber Borders Keep Gravel Inside Each Tread
A closer view shows how the stair framing ties into the retaining wall. Timber risers contain the gravel, while wide wood edges define the route through the change in elevation.
The steps avoid pouring more concrete against the hillside and use the same lumber as the wall, connecting the access point to the structure beside it.
Steel and Wood Leave Room for Future Repairs
The wall’s materials remain visible rather than hiding the support system. Steel uprights sit between replaceable timber sections, while the top cap runs across the wall as a continuous edge.
That separation matters for a wood retaining structure. If individual timbers deteriorate over time, the steel framework does not depend on a continuous wood post buried beside the driveway.
Gravel Steps Turn the Wall Into a Route Up the Slope
From the upper angle, the stairs show their full connection to the retaining wall. Three gravel-filled levels climb beside the brick wall, with timber borders creating broad treads rather than a narrow staircase.
The project leaves most of the existing concrete untouched while adding a retaining barrier and a route to the higher section of the property. What had been an exposed bank meeting the driveway now has a defined wood-and-steel boundary built around the slab already in place.
All image credits go to Reddit user u/Mrcraigt.