St. Louis County, MO
Foundation Piering Cost in St. Louis County — Per-Pier Ranges, Drain Tile & Sump Integration
Foundation repair pricing looks opaque because most quotes arrive as a single number. It isn't opaque underneath: piering is priced per pier, drain tile is priced per linear foot, and the sump system is a fixed assembly. Once a bid is broken into those three units, two contractors become directly comparable. Here are the ranges to expect in St. Louis County and what moves a project within them.
How much does foundation piering cost per pier in St. Louis County?
Installed piers in St. Louis County generally run about $1,400 to $2,500 each, driven mainly by depth to bearing strata and site access. A typical West County settlement job needs four to eight piers, landing most projects in the $6,000 to $8,000 range.
Depth is the single largest cost variable and the one nobody can promise before installation begins, because the pier stops when it reaches competent strata — not at a number written in a proposal. That's why a credible quote states three things: the per-pier unit price, the assumed depth included in it, and the cost per additional foot beyond that assumption. Access is the second lever. Piers installed along an exterior wall reachable by a compact excavator are meaningfully cheaper than interior piers hand-dug through a finished basement, and a slab-on-grade or attached-garage location carries its own premium. Pier count comes from the engineer's plan, not from perimeter length, so a small localized settlement can be a four-pier job on a large home.
How much does an interior drain tile system cost in St. Louis County?
Interior drain tile runs roughly $55 to $95 per linear foot installed, so a partial run lands near $4,000 and a full basement perimeter can reach $12,000. Price varies with slab thickness, access, and whether a new sump pit is required.
The work is more invasive than the price suggests: a channel is cut through the slab along the footing, perforated pipe is bedded in washed gravel, a vapor membrane is often run down the wall into the trench, and the slab is patched back. Slab thickness and reinforcement drive the demolition cost, and finished basements add restoration that rarely appears in the drainage line item — ask explicitly who is putting the flooring back. Whether you need a full perimeter or a single wall depends on where water is entering, which is a question a moisture survey answers and a sales visit tends to answer generously. In West County the wall facing the poorest exterior grade is usually where a partial system earns its keep.
Does a piering quote include the sump pump and drainage work?
Usually not. Piering addresses settlement, while drain tile and a sump pump address water. Expect them as separate line items, and ask the contractor to price them in one mobilization since both require excavation along the footing.
Bundling matters financially because mobilization, excavation, and slab work are the shared costs. A homeowner who piers this year and installs drain tile next year pays for the same trench twice. A sump pit and pump typically adds $900 to $2,500, with a battery backup at another $700 to $1,500 — worth specifying in St. Louis County, where the storms that raise the water table are the storms that cut power. Confirm the discharge terminates well away from the foundation and does not tie into a sanitary sewer, which is prohibited in most local jurisdictions and is a common finding when someone else's earlier work gets inspected.
| Scope Item | Typical Range | Priced By |
|---|---|---|
| Steel push or helical pier, installed | $1,400 – $2,500 each | Per pier, plus cost per foot past assumed depth |
| Typical West County piering project (4–8 piers) | $6,000 – $8,000 | Pier count from the engineer's sealed plan |
| Interior drain tile | $55 – $95 per linear foot | Linear feet of perimeter treated |
| Sump pit and pump | $900 – $2,500 | Fixed assembly; add $700–$1,500 for battery backup |
| Carbon fiber wall strap | $600 – $1,000 each | Per strap, typically on 4-foot centers |
| Independent engineer report | $400 – $900 | Flat fee, paid directly by the homeowner |
Planning ranges reflect typical St. Louis County residential conditions. Actual pricing depends on depth to bearing strata, access, slab construction, and the engineer's specified scope — get competing bids against one written plan.