The one part of a house no contract covers
A foundation is excluded from every mainstream home service contract, at every tier, in every state. There is no foundation plan, add-on or endorsement in the market. This is not a gap in the product; it is the boundary of the product.
The reason is definitional. A home service contract covers the mechanical and electrical breakdown of systems and appliances from normal wear. A foundation is not a system that breaks down. It is the element transferring the building's loads to the ground — footings, foundation walls, piers, or a slab on grade — and together with the framing above it forms the load-bearing system, which is to say, the building. One provider says so in its own consumer material: home warranties cover the systems and appliances inside a home, not the structure holding it together, and foundation cracks and load-bearing elements fall outside standard coverage.
Three layers of exclusion, and the slab-leak trap
Contracts exclude foundations three times over, and two of the three never mention the word.
- The covered-items schedule is a closed list. Coverage is granted by enumeration; if an item is not on the schedule it is not covered, and no schedule lists structure.
- A structural exclusion. One widely circulated sample agreement excludes items involving structural and/or property damage.
- A construction and carpentry exclusion. The same agreement excludes construction, carpentry, or other modifications made necessary by the repair or replacement.
That third layer bites even when the underlying failure is covered. In slab regions, a leak on a covered water line beneath the slab can get the line repaired up to the cap, while the jackhammering, backfill, concrete and flooring restoration are the homeowner's. The plumbing is covered; the hole in the house is not.
Ask this about any under-slab coverage before relying on it: does the contract pay for access and restoration, or only the component? On most published forms the answer is only the component — and access is the larger number.
Observation is not evaluation
The distinction that matters most is between what a home inspector may say and what a structural engineer is qualified to conclude. Confusing the two is how buyers end up unprotected.
Under the ASHI standard, the inspector shall inspect and describe the visible, accessible structural components including the foundation and framing — but is not required to provide engineering or architectural services, to offer an opinion about the adequacy of structural systems, or to inspect footings. The InterNACHI standard covers the foundation, basement, crawlspace and structural components and requires reporting wood in contact with soil and active water penetration, while relieving the inspector of determining foundation bolting adequacy.
So the ceiling of an inspector's finding is a sentence of this shape: diagonal cracking at the southeast corner; recommend evaluation by a licensed structural engineer. That is not hedging. In most states, rendering a cause-and-repair opinion would be the unlicensed practice of engineering.
A licensed structural or geotechnical engineer does something categorically different: measures floor elevations with a manometer or laser level, correlates crack patterns to a movement mode — heave, settlement or lateral pressure — determines cause, and issues a stamped, signed report with a repair specification carrying professional liability. Only that document is relied on by lenders, insurers, litigants and pier contractors.
Concealment compounds the difference. ASHI's exclusions state that inspections are not technically exhaustive and that inspectors need not identify concealed conditions or latent defects. A slab is concealed by flooring; a crawlspace wall by insulation or storage; footings are underground and out of scope. So a general inspection produces a recommendation, and an engineer's evaluation produces an answer. If the buyer does not follow through, nobody is left holding the question except the buyer.
“Major structural defect” is a defined term, not a description
Structure is warranted in exactly one place: a builder's warranty on a new home, in the ten-year tier. The phrase that tier turns on is a defined legal term, not a description of a serious problem, and nearly every private version traces to one federal formulation.
HUD's regulation at 24 CFR 203.200 defines a structural defect as actual physical damage to the designated load-bearing portions of a home caused by failure of such load-bearing portions that affects their load-bearing functions to the extent that the home becomes unsafe, unsanitary, or otherwise unlivable. It enumerates the load-bearing components — footings, foundation, beams, columns, load-bearing walls, roof framing, floor systems — and lists what is not load-bearing and therefore can never be a structural defect: roofing, drywall, siding, electrical, plumbing and appliances. GovInfo publishes the regulation text.
The largest private structural-warranty administrator uses the same three-part test: physical damage to a designated load-bearing element; damage caused by the failure of such an element; and failure rendering the home unsafe, unsanitary or otherwise unlivable. Its Designated Load-Bearing Elements are a closed list of nine — roof framing, load-bearing walls and partitions, beams, columns, footings and foundation systems, floor framing, girders, lintels, and masonry arches.
The consequence is severe. A slab that has heaved, cracked and thrown every door out of square is frequently not a covered major structural defect, for two reasons: the home is still safe, sanitary and livable, and the cause is soil movement, which the exclusions reach separately. Ten-year structural coverage is catastrophic-failure coverage, not foundation-performance coverage.
Where the severity threshold is genuinely contested
The threshold is not settled nationally, and statutory programs can be more generous than the HUD formulation.
New Jersey's New Home Warranty regulation defines a structural defect as an actual or pending structural failure of some part of the load-bearing system, with load-bearing elements defined as framing members and structural elements that transmit both dead and live loads — roof rafters, floor joists, bearing partitions, beams, columns and foundation walls. The defect must vitally affect residential use, but the rule provides that the home need not be uninhabitable: a materially lower bar than "unsafe, unsanitary, or otherwise unlivable." The applicable standard depends on the state and the document, and the sources genuinely disagree.
What is consistent is the exclusion architecture. Private structural warranties commonly exclude earth or soil movement caused by earthquake, volcanic eruption, sinkhole, mineshaft, avalanche, landslide, plate tectonics or mudflow; changes in the underground water table; and mold, mildew, fungi, rot, decay, corrosion or other gradual deterioration. New Jersey's rule excludes owner-caused grade changes, flood, storm perils, improper loading, fire, and water seepage in a basement or crawlspace after the first year.
For the shorter tiers, the Federal Trade Commission summarises the common 1-2-10 structure: year one covers workmanship and materials, two years covers HVAC, plumbing and electrical, and some builders give up to ten years for major structural defects. Builder warranties typically do not cover temporary housing, appliances, or small cracks in brick, tile, cement or drywall — and the FTC's illustration of a major structural defect is a roof that could collapse, which shows how far the threshold sits from a cracked slab.
Expansive clay, and why the physics matches the exclusion
Expansive soils are fine-particle, clay-based soils that expand in volume when exposed to water, swelling by adsorption as water molecules attach to the clay particle surfaces. Soils capable of damaging foundations may contain as little as five percent of the active mineral and may exert as much as 5,500 pounds per square foot of pressure. The highest-abundance zones on the USGS swelling-clay map are in the Southwest, South-Central states and parts of the Great Plains. Mitigation happens at the design stage: piers below the zone of water-content fluctuation, doubled or floating bottom plates, grade correction and moisture barriers. InterNACHI reproduces the USGS map and the mitigation approaches.
Now match the mechanism to the exclusions. Expansive-soil movement is seasonal moisture cycling — gradual, cumulative and drainage-driven. That places it inside the structural warranty's gradual-deterioration and soil-movement exclusions, outside the service contract's mechanical-breakdown grant, and inside the homeowners policy's exclusion of settling, shrinking, bulging or expansion of foundations, walls and floors.
The result is worth stating without softening: foundation movement from expansive soil is uncovered by the home warranty, uncovered by the structural warranty, and uninsured under a standard homeowners policy. A widely repeated statistic holds that expansive soil causes greater annual loss in the United States than hurricanes, floods, earthquakes and tornadoes combined, but the page carrying it gives no source, so treat it as circulated rather than verified.
Foundations do not fail from age
The concrete itself is not the problem. The commonly cited life-expectancy chart gives poured-concrete footings and foundations 100 years or more, concrete block 100 or more, slab on grade around 100, and steel and timber framing 100 or more. Foundations almost never fail because they got old.
They fail because of what is underneath and around them: expansive soil cycling, poorly compacted fill, footings undermined by a plumbing leak, tree root moisture extraction, and — most commonly, and most cheaply fixed — surface water. Concentrated roof runoff at the perimeter is the most controllable input in the chain, which is why gutters are a foundation issue rather than a cosmetic one.
Whether a crack matters turns on whether the movement is active. A hairline crack that has not moved in a decade is a different object from one with fresh spalling, offset faces, or a monitor showing displacement. Only measurement across time answers that, and no one-day inspection can — a limitation of the format, not of the inspector.
What a buyer should settle, and when
The foundation decisions worth making are the early ones, and each expires.
Order the engineer inside the option period. When a report recommends evaluation, that recommendation has a shelf life measured by the contingency deadline. "The seller says it is normal settling" is not an answer; every foundation issue is normal settling until an engineer measures it.
Ask soil and design questions in an expansive-clay region. Soil type, foundation type — post-tension slab versus conventional — and the drainage plan all have answers, and they are cheaper to ask than to discover.
Verify structural warranty transfer in writing on a newer resale. Coverage transfers to subsequent owners under many programs, but that is a document term, not a custom.
On a new build, treat the eleven-month mark as a hard deadline. The year-one workmanship tier is where most foundation-adjacent complaints belong — cracks, doors out of square, grade and drainage defects — and it closes at twelve months whether or not anyone has looked.
Frequently Asked Questions
Is there any home warranty plan that covers foundation repair?
No. There is no foundation tier, no add-on and no endorsement in the mainstream home service contract market. The product covers breakdown of systems and appliances from normal wear, and a foundation is neither.
Three mechanisms exclude it: a covered-items schedule that is a closed list; a structural exclusion removing items involving structural or property damage; and a construction and carpentry exclusion removing the concrete and restoration work even where the underlying failure was covered.
My builder's warranty says ten years structural. Does that cover my cracked slab?
Probably not, and the reason is the definition rather than the facts. Major structural defect is a defined term requiring actual physical damage to a designated load-bearing element, caused by the failure of that element, to the extent the home becomes unsafe, unsanitary or otherwise unlivable.
A slab that has cracked and thrown doors out of square usually fails that test twice: the home is still livable, and the cause is soil movement, which the exclusions reach independently. Some statutory programs use a lower threshold, so the state and the document both matter.
What is the difference between the inspector's foundation finding and an engineer's report?
The inspector observes a visible condition and recommends evaluation. The standards forbid providing engineering services or opining on the adequacy of structural systems, and in most states going further would be the unlicensed practice of engineering.
An engineer measures floor elevations, correlates crack patterns to a movement mode, determines cause, and issues a stamped, signed report with a repair specification carrying professional liability. That is the document lenders, insurers and courts rely on.
Does homeowners insurance cover foundation cracks?
Generally not where the cause is movement. The standard homeowners special form excludes settling, shrinking, bulging or expansion, including resultant cracking, of foundations, walls, floors, roofs or ceilings by name.
That exclusion, with the service contract's structural exclusion and the structural warranty's soil-movement exclusion, is why foundation movement is one of the few large residential losses with no product behind it. A sudden accidental cause is a different analysis from movement over seasons.
Why are expansive clay soils such a problem for foundations?
Expansive soils are clay-based soils that swell as water molecules adsorb onto the clay particle surfaces. A soil with as little as five percent of the active mineral can damage a foundation, and such soils may exert as much as 5,500 pounds per square foot of pressure.
What makes them an exclusion problem as well as an engineering one is the time signature. The movement is seasonal moisture cycling — gradual, cumulative and drainage-driven — which is precisely the language every relevant exclusion uses.
If a covered plumbing leak is under my slab, who pays for the concrete work?
Typically the homeowner. Published forms exclude construction, carpentry or other modifications made necessary by the repair, which separates repairing the pipe from opening and restoring the slab and flooring above it.
The covered portion of an under-slab water line failure can therefore be a fraction of the total bill. Before relying on that coverage, establish from the contract whether it funds access and restoration or only the component.
Does an inspection report saying “no major structural concerns” mean the foundation is sound?
No. It means nothing structurally significant was visible on the day, from the accessible side, without moving anything, to an inspector whose standard bars offering an opinion on structural adequacy.
Concealment is severe for foundations: a slab is covered by flooring, crawlspace walls by insulation or storage, and footings are underground and outside the scope. The standards also state that inspections are not technically exhaustive.