This home in Hamilton was built using pre-cast concrete panels and stood on a sloping lot.
Pre-cast concrete panels are an innovative product, they don’t need footers and can be laid in a day. They are also less expensive and designed to be built on immediately. When these panels are part of a well-engineered design and installed correctly, they can be both cost-effective and time-saving. Below you can see how they should be installed:
Unfortunately, in this case the space that should have been empty, interior space was backfilled with “grits”, (An industry term for a type of sandy, uncompactable fill) under the garage slab. See below:
This type of soil cannot be compacted, and it tends to flow outwards when not contained properly. Having this soil piled against the pre-cast interior wall was not what these particular panels are designed for. Because of this, the wall was being pushed outwards by the fill material and the slab above had cracked.
The goal was to implement a solution that resolved the structural deficiency while being aesthetically acceptable. Since much of the exterior wall was above-grade they requested there be no visible repairs (such as counterforts) and they wanted the structure to be brought as close to plumb as possible.
To achieve these goals Cole Engineering designed a concrete retaining wall to run under the garage floor along the North wall. With a footing leg toward the South. The footing leg would keep the wall from rotating outward under pressure from the fill because the same fill pressure is also holding the footer down.
This interior retaining wall would help to contain the fill and also to provide extra support to the garage slab. With the soil no longer piled up against the walls, the panels can now function as they were meant to.
Stabilizing the outer wall
As you can see above, the top of the retaining wall is anchored to the top of the panel wall to ensure its stability. To provide support for the bottom of the wall, we installed helical piers with lift brackets. This should prevent any future movement, and as a bonus, the repair is completely hidden.
No one would ever know there was this tunnel under there. Personally, I would have added a secret door, but these homeowners opted to seal it up instead.
With all the structural work complete, we re-poured the whole garage slab and a portion of the driveway as well. This garage looks brand-new and is ready to support the weight of vehicles, toys and tools for years to come.
Do you have any leaning, cracking, or bowing walls at your home or business? Please contact us and let us walk you through the process.
At Hughes Construction, we aren’t salespeople. We won’t just come out and give you an estimate for work that may or may not fix the issue.We will most likely tell you to call an engineer. This will enable you, as the homeowner, to know what it is you need done and why.