Hiring a Retaining Wall Contractor in Wheeling, IL: What Separates the Bids
Slope is the reason most homeowners start looking for a retaining wall contractor in Wheeling, IL, and it is also the reason the bids come back so far apart. One quote prices a stack of block. Another prices an engineered structure holding several tons of saturated soil.
Bertog Landscape has served homeowners, associations and commercial properties across Wheeling and Chicago's North Shore since 1974, long enough to have repaired plenty of walls built the first way.
A wall is a soil retention system, and the visible stone is the smallest part of it. What sits behind and beneath the face determines how straight the wall stands in fifteen years.
Related: How a Retaining Wall Solves the Slopes and Grade Changes That Limit Your Yard in Verona, WI.
What Goes Behind A Properly Built Wall?
A drainage aggregate zone at least twelve inches deep runs the full height of the wall, separated from native soil by geotextile so fines cannot migrate in and clog it. A perforated drain line sits at the base and daylights somewhere the water can go.
Above roughly four feet, geogrid layers extend back into the retained soil at engineered intervals. Skip any one of these and the wall holds water instead of soil, which is how walls lean.
The face material is a preference. Segmental block, natural outcrop stone and mortared cut stone each hold soil when the structure behind them is right, and each fails the same way when it isn’t.
We choose the face for how it sits against the house and the existing grade, then design the retention independently of that choice.
Why Does Local Clay Make Drainage The Whole Argument?
The heavy clay under most of this area drains slowly and expands as it takes on water. A wall backfilled with that same clay becomes a dam.
Through a wet spring the pressure behind the face climbs well past what the block was rated for, and the first sign is usually a bulge two-thirds of the way up.
We excavate a full drainage chimney behind every wall rather than backfilling with spoil, which is the same reasoning behind what clay soil does to a paver base.
How Deep Should The Base Course Sit?
The base trench gets excavated below grade and filled with compacted aggregate, with the first course buried so that roughly one inch of wall sits below finished grade for every foot of exposed height. On sloped ground the base steps down in level runs rather than following the grade.
Frost movement in this climate lifts anything set on unimproved subgrade, so compaction gets tested in lifts rather than assumed.
Base preparation is also where schedule pressure shows up. Excavating, placing aggregate and compacting in six-inch lifts takes a full day on a wall a crew could otherwise stack in an afternoon. A bid that is noticeably faster and cheaper than the others is usually pricing the afternoon.
When Does A Wall Require Engineering Or A Permit?
Most local jurisdictions in Cook and Lake counties set a threshold around four feet of exposed height, above which a stamped design and a permit apply.
Surcharge conditions lower that threshold, since a driveway, a pool, or a second wall above the first all add load the block was not rated for.
A contractor who tells you height is the only variable has not looked at what sits behind the wall. We flag surcharge during the site visit, before a number goes on paper.
What Should You Ask A Contractor To Show You?
Ask for photographs of the excavation stage rather than the finished face, since anyone can build a straight top course on a bad base.
Ask which block system they are certified to install and what the manufacturer requires for grid spacing at your height. Ask where the drain daylights.
Homeowners across Wheeling, Wilmette, Winnetka and the surrounding North Shore tend to find that these three questions narrow a field of bids quickly.
Walk Your Slope With Us
Grade problems get more expensive the longer they move. Contact Bertog Landscape to schedule a retaining wall site visit in Wheeling, IL, and we will look at where your water goes before we talk about stone.
In Summary
How long should a properly built wall last?
A drained, engineered segmental wall typically performs for decades. Failures we are called to repair are usually under fifteen years old and nearly all trace to backfill.
Can a leaning wall be repaired without rebuilding?
Occasionally, if movement is minor and drainage is the only defect. Once the base has shifted, rebuilding from the footing is the durable answer.
Can a retaining wall double as seating?
A wall in the eighteen to twenty-two inch range with a cut cap works well as seating around a terrace, and we detail many that way.
Does a wall need to be rebuilt if only one section has moved?
Not always, though the section that moved is rarely the whole problem. Movement in one run usually points to drainage or base failure that extends past the visible bulge, so the repair gets scoped from where the water is going rather than from where the face is out of line.
How much does a second wall above the first change the design?
Considerably, because the upper wall becomes surcharge load on the lower one. Terraced walls need a designed separation distance or a single engineered structure, and stacking two walls too close is one of the more common reasons a lower wall fails early.
