Foundation Footing Repair: How Failing Footings Are Diagnosed and Fixed

What a Foundation Footing Does

A foundation footing spreads the weight of the house over a wider strip of soil than the wall above could stand on by itself. Soil can carry only so many pounds per square foot before it compresses, so an 8-inch wall set straight on clay would press into it. On a footing two or three times wider, the same load is spread until the soil can hold it.

Most houses rest on a mix of footing types:

• Continuous spread footings. A strip of concrete under every exterior wall, and under interior bearing walls in many basements. This is what most people mean by “the footing.”
• Pad footings. Square pads under posts, piers, and basement columns. Problems with these in crawl space houses belong to pier and beam foundation repair.
• Thickened slab edges. A deeper band of concrete around a slab’s perimeter, poured with the slab. Repairs follow slab foundation repair methods.
• Footings under stem walls. A short concrete or block wall, the stem wall, rises from the footing to lift the framing or slab above the soil. Stem walls get their own section below.

Because the footing is buried, its failures show up in the wall, floors, and doors above, and often get patched as mere wall cracks.

What the Building Code Requires for New Footings

Chapter 4 of the 2021 International Residential Code (IRC) sets the minimums for footings in new houses and additions, and a new footing section poured under an existing house is generally designed to the same rules. The table draws on that chapter and on a 2021 IRC footing inspection checklist published by MyBuildingPermit.com, a group of Washington State building departments.

Frost protection is the most misunderstood rule. Fine Homebuilding’s code columnist points out that Section R403.1.4.1 offers four equal options: extend the footing below the local frost depth, build a frost-protected shallow foundation under Section R403.3, design to the ASCE 32 standard, or bear on solid rock. Digging below frost depth is just the most common choice, and the frost depth itself is set by your local jurisdiction.

These are minimums for new work. An older, undersized footing that has carried a house without movement for decades is not automatically a problem; the tables matter when a footing is replaced, enlarged, or extended.

How Footings Fail in Existing Houses

Footings fail in a handful of ways, and each points to a different repair. Stem wall cracks and separation, often the most visible result, are covered in the stem wall section further down.

Cracked Footings

Footings crack from shrinkage, point loads such as a chimney, and above all differential movement, where one part drops or rises relative to the next. Many older footings have no reinforcing steel to hold the pieces together once they crack. A hairline crack with no offset is common and usually harmless. A crack where one side sits lower, or one that lines up with a crack running up the wall, means the footing has broken.

Settled Footings

Settlement happens when the soil under the footing compresses or disappears. The usual causes:

• Soft or disturbed soil. Loose material left in the bottom of the trench, organic soil, or soil dug out and thrown back in.
• Poorly compacted fill. On sloped or filled lots, footings sometimes sit on fill that was never compacted and keeps consolidating for years.
• Plumbing leaks. A leaking line beside or under the footing softens clay and can wash fine soil out from beneath it.
• Erosion. A downspout that dumps roof water at one corner carries soil away from the footing edge.
• Shrinking clay. Expansive clay loses volume as it dries, especially near large trees and during drought.

The broader pattern is covered in foundation sinking, and the soil and water causes behind it in what causes foundation problems.

Undersized or Missing Footings

Some footings were never big enough. Older houses may have footings narrower than today’s tables, and stone foundations often start on flat stones rather than a concrete footing. A later addition may sit on a shallower or narrower footing than the original house, and the two parts settle at different rates and crack along the joint. Porches, sunrooms, and attached garages were often built on a shallow footing or slab edge that never reached frost depth.

Frost-Heaved Shallow Footings

A footing above the frost line can be lifted by freezing soil. As Fine Homebuilding explains, water in frost-susceptible soil collects into ice lenses that push the soil above them upward. When the ice melts, soil slumps into the gap, so a lifted footing settles back slightly higher than before and the movement ratchets over the years. Heave needs frost-susceptible soil, water, and freezing temperatures at once, and removing any one stops it. The classic sign is a porch or garage that rises in winter and drops in spring. Upward movement from swelling clay is a different problem, explained in foundation heave.

Exposed or Undermined Footings

When footing concrete that should be buried is visible, or soil has washed out from under its edge, the footing has lost both bearing and frost cover. Typical causes are runoff from roofs and paving, regrading that lowered the soil, and nearby excavation such as a utility trench.

Deteriorated Concrete

Weak or overly wet concrete, or concrete kept wet for decades, can soften and crumble. Freeze-thaw cycles break down saturated concrete near the surface, and rusting steel splits reinforced concrete from inside. Concrete you can scrape away with a screwdriver has to be replaced.

How a Footing Problem Shows Up Above Ground

You almost never see a footing fail. You see what its movement does to the house above it.

How Footing Problems Are Diagnosed

A footing problem is confirmed by measuring the house and then looking at the footing itself, ideally through an independent structural engineer evaluation. A structural engineer foundation inspection separates old movement from active movement and names a cause rather than a product; see foundation inspection cost for pricing. A thorough diagnosis usually includes:

• An elevation survey. A manometer or laser level reads floor elevations across the house. A low zone that follows one wall points to the footing under it, and a second survey months later shows whether it is still moving.
• Test pits. A hole dug beside the footing is the only way to see its width, depth, condition, and what it bears on. Many repair decisions hinge on what the pit reveals.
• Soil information. The USDA’s Web Soil Survey maps the soil types under a property and rates them for building, which flags problem clays before anyone digs. Larger repairs may call for a geotechnical report with borings.
• Plumbing tests. When settlement is localized near a bathroom, kitchen, or laundry, a pressure test rules a leaking line in or out.

Before any test pit, someone must contact 811. The national before-you-dig service asks that you reach your state 811 center a few business days ahead and wait until every utility has marked its lines.

Foundation Footing Repair Methods

The right repair depends on what failed: the concrete, the soil under it, or the water and frost acting on that soil. Broken or undersized footings get new concrete, weak soil gets support from deeper ground, and water or frost causes get drainage or insulation. Many jobs combine two of these.

Sectional Footing Replacement or Enlargement

When it fits: the footing is broken, crumbling, or too small, but the soil at footing depth is sound.

How it is done: An engineer designs the new footing and the work sequence. The crew shores the framing with temporary posts and beams, hand-digs a short section beside and under the wall, removes the damaged concrete, sets reinforcing steel doweled into the footing on each side, and pours a new footing that meets current size rules. Sections are dug in alternating order, and a neighboring section is opened only after the last has cured, so the wall is never unsupported over a long span. Enlargement works the same way, adding a wider footing tied to the old one with steel.

Mass Concrete Underpinning

When it fits: the soil at the current footing depth is weak, but firm soil is within reach of a hand-dug pit.

How it is done: Pits are dug beneath the existing footing in a staged sequence and filled with concrete, so the foundation bears on deeper soil. It is slow, labor-heavy work, and the foundation underpinning guide compares it with pier-based methods.

Push or Helical Piers Under the Footing

When it fits: firm soil is too deep to reach by digging, and the footing is sound enough to carry a bracket.

How it is done: Steel brackets are fastened to the footing at set spacing. Push piers are driven hydraulically using the weight of the house as resistance. Helical piers are screwed in and verified by installation torque, which suits lighter loads such as porches, additions, and garages. A crumbling footing cannot transfer load to a bracket, so a failed section may need replacing, or a new concrete beam cast, before piers go in.

Drainage Fixes for Undermined Footings

When it fits: water has washed soil from beside or under the footing, or keeps the bearing soil saturated.

How it is done: Voids under the footing are filled with concrete or grout as the engineer specifies, then the water source is cut off: downspout extensions, regrading so soil falls at least 6 inches in the first 10 feet (the IRC’s R401.3 standard for new work), and sometimes a footing drain. Without the water fix, any structural repair is fighting the cause.

Frost Protection for Shallow Footings

When it fits: a porch, garage, or addition sits on footings above the frost line and heaves seasonally.

How it is done: One route is deepening the support below frost depth with underpinning or piers. The other uses insulation to keep the soil under the footing from freezing. A HUD report on frost-protected shallow foundations notes the approach can solve existing frost-heave problems by retrofitting protective insulation, including for unheated garages and porches. According to Fine Homebuilding, the IRC’s version covers heated buildings kept above 64°F year-round, while unheated structures fall under ASCE 32, so a retrofit needs engineering.

Matching the Footing Problem to the Repair

Stem Wall Foundation Repair

A stem wall is the short foundation wall between the footing and the house, and stem wall foundation repair fixes cracks, spalling, and separation in that wall along with the footing problems that often cause them. Stem walls appear in two common layouts:

• Slab on stem wall. A perimeter footing and stem wall are built first, and the floor slab is poured inside them, raising the slab above grade.
• Crawl space stem wall. The perimeter wall carries the sill plate and floor framing, with pad footings and posts supporting the floor inside.

Common Stem Wall Problems

• Vertical and stair-step cracks. Usually settlement of the footing below. Sealing them without fixing the footing means they reopen.
• Horizontal cracks and leaning. Taller stem walls hold back soil, and wet or expansive backfill can push them inward.
• Rust stains and spalling. Moisture reaches the reinforcing steel, which rusts, expands, and pops off the concrete cover. Sprinklers hitting the wall and downspouts discharging beside it are frequent culprits.
• Slab-to-stem-wall separation. A gap opens where the slab meets the stem wall when one settles differently from the other.
• Sill rot. The IRC requires the top of a new foundation wall to sit at least 6 inches above finished grade (Section R404.1.6). Older walls with soil or mulch piled against them lose that margin, and the sill plate stays damp.

Stem Wall Repairs

The repair follows the cause. Settlement cracks are stabilized at the footing first, by sectional replacement or piers, then sealed or injected. Spalling is repaired by removing damaged concrete back to sound material, cleaning and treating the steel, adding bars where too much has rusted away, rebuilding with repair mortar, and stopping the water. A stem wall that is badly cracked, leaning, or deteriorated along a long run is rebuilt in shored sections, often with a new footing beneath it.

Permits and Engineering for Footing Work

Footing repair is structural work, so most jurisdictions require a building permit, and many require a design or letter sealed by a licensed engineer. Haltom City, Texas, is a typical example: since 2014 it has required a permit for foundation repair, an engineer’s sealed letter locating the piers and footings with the application, and an engineer’s final report confirming the work matched the design before final inspection.

Expect engineered plans, an inspection before concrete is placed, and a final inspection. A contractor who offers to skip the permit is handing you a problem at resale, when buyers ask for records of structural work. Confirm what applies at your address with your building department.

What Foundation Footing Repair Costs

Footing repair is priced by how much digging, shoring, and concrete it takes, and access matters more than materials. HomeAdvisor puts new concrete footings at about $5 to $18 per linear foot, yet replacing footings under an existing foundation starts around $1,500 and can exceed $12,000 for large jobs. The concrete is cheap. Hand-digging under a loaded wall, shoring the house, and pouring in sequence is what costs money.

Most pier jobs total $8,000 to $30,000. Add engineering, the permit, and restoring finishes or slabs that had to come out. Getting an engineer’s evaluation before collecting bids lets you compare quotes against one scope.

Related Guides

• Foundation Underpinning Cost
• Old House Foundation Repair
• Crumbling Foundation Walls
• Crawl Space Foundation Repair
• Foundation Repair Methods Compared