Best here is a published score, not an opinion: years in business, review volume, rating and a verifiable website, weighted the same for every company. We reviewed 79 foundation repair companies across St. Louis to build this list, and every company below carries the same seven facts - so you can compare them without opening 25 tabs.
Fixed weights, applied identically to every company: years in business, review volume, rating, verifiable website. Rating and review count are Google's, read in August 2026. Years in business is what the company states on its own site or in its state registration - where neither says, the figure is marked unverified.
Bids on the same house routinely differ by a factor of two, and the cheapest is not reliably the worst or the best. The only way to know what your repair should cost is to have more than one company look at it.
Or just call them directly - these are the numbers each company publishes itself. We don't insert tracking numbers, and we aren't paid when you call.
Every company listed here serves inside the outlined area. Most travel further for a large job - the boundary is where they routinely quote, not a hard limit. Where a town shows a number, that is how many listed companies are based there; plenty of towns are covered without having a foundation company headquartered in them.
St. Louis is the only market we cover where the ground can be genuinely missing. Everywhere else on this site the problem is soil that moves - clay that swells, shrinks or pushes. Here the bedrock is limestone, and limestone dissolves. That produces karst: caves, underground streams and sinkholes, in a metro where houses sit directly on top of it.
The effect is concentrated in south St. Louis city and the Illinois Metro East. Benton Park and Benton Park West are built over known cave systems, and much of south city was quarried for limestone in the 1800s and then built over - the 1876 Compton and Dry survey still shows where the pits were. Across the river, the sinkhole plain runs through St. Clair and Monroe counties. A house over a void does not settle evenly; it drops at one corner, and no amount of pier work fixes a hole. That is a geotechnical question before it is a foundation-repair question, and it is worth knowing which one you have.
The second local problem is the age of the housing stock. St. Louis has one of the oldest inventories of any large American city, and a great many pre-1900 brick houses stand on limestone rubble foundations - stacked stone laid up with lime mortar, not poured concrete and not block. Rubble walls fail differently. The mortar washes out, the stones shift, and the wall bulges. The repair is repointing, parging or rebuilding a section, and a contractor whose entire product line is steel piers may quote you piers for a wall that needs masonry instead.
Then there is ordinary clay, which St. Louis has plenty of, and the river bottoms - the American Bottom on the Illinois side, and the Missouri and Meramec floodplains on the Missouri side. Those are alluvial silt and sand with a high water table, so the failure there is water pressure against a basement wall rather than movement under a footing.
Add a real freeze-thaw winter on top of all of it. Four different failure modes - subsidence, rubble-wall decay, clay movement and hydrostatic pressure - need four different repairs, which is the strongest argument there is for getting more than one company to look before you sign anything.
St Louis splits between waterproofing and structural work more evenly than any other metro we cover. Of the 8 companies naming a method, 50% install steel piers, but the firms at the top of this list describe themselves first as basement waterproofers - and several of the best-reviewed do masonry repair on stone foundations as well. That mix is what an old housing stock over karst limestone produces: three different failures, three different trades, and companies that have had to learn all of them.
Every figure here is counted across the 25 companies listed above, not across the wider market. The oldest on the list has been in business 71 years, and together the 25 carry 9,852 Google reviews.
Settlement is gradual and usually shows along one side of the house. A karst void tends to produce sudden, localised dropping - one corner, a section of floor, or a hole opening in the yard - and it can appear after heavy rain. If you are in south city or the Metro East and something moved quickly, ask for a geotechnical opinion before a repair quote. Piers installed over a void do not solve it. Nine things that should end the conversation →
Substantially. A limestone rubble wall fails when its mortar erodes and the stones move, so the fix is masonry work - repointing, parging, sometimes rebuilding a section - not piering. Piers address a foundation that is sinking. If your wall is bulging and the mortar is sandy to the touch, a company that only installs piers is the wrong company to be quoting it. The four methods compared →
Because this is a basement metro, and in a basement the most common call is water. A wet basement and a failing wall are related - hydrostatic pressure does both jobs - so the same firms handle drainage, sump systems, wall anchors and crack repair. It is not a sign they cannot do structural work; in this market it is the normal shape of the trade. What repair actually costs →
No. Belleville, Edwardsville, Collinsville and Granite City are part of the St. Louis metropolitan area, and the two largest firms in this directory are both based in Illinois and work throughout eastern Missouri. Check that they are licensed and insured for work in your state, which is a paperwork question rather than a distance one.
We collected every foundation repair company operating in St. Louis from public listings - 79 of them - then opened each company's own website and read it. Seven attributes were recorded, and only what the company states publicly. Nothing here is inferred, estimated, or paid for.
51 were excluded: no working website to verify against, too few reviews to judge fairly, based outside the area, running a network of city-named microsites, or not a foundation company at all - foundation searches surface a lot of roofers and handymen by the second page of results.
The full method, including the ranking weights and the disqualifier list →