01 — The short version
Sixty seconds, then the details
That's not a joke. Under a wide band of Central Texas sits a clay that swells when it gets wet and shrinks when it dries out — not a little, but enough to lift and drop the concrete slab your house is built on.
It isn't settling. Settling happens once, in one direction, and then it's over. This is different: the ground goes up and down with the seasons, year after year, for as long as the house stands. What breaks a house isn't the movement — it's differential movement, one part of the slab going one way while another part stays put.
How much? The USDA's own description of Houston Black clay — the Texas state soil, and the one everybody names — records that when it dries, it opens cracks half an inch to four inches wide. Its neighbour Branyon cracks one to three inches wide, reaching twenty inches down or more. Those are surface cracks, not slab movement, but they tell you what the material does when it loses water.
USDA NRCS Official Soil Series Descriptions — Houston Black, Branyon
That's the whole mechanism. Everything else on this page is either where it's worse, how to see it, or what you can actually do about it.
Houston Black gets called "the soil under San Antonio" constantly. That's too simple. Bexar County is split into three different worlds by the Balcones Escarpment, and which one you're in changes everything:
- Far north Bexar — shallow soils over limestone. This is caliche country. Low shrink-swell, but rock excavation and drainage are the headaches.
- Mid-county — the Blackland Prairie. Thick expansive clay. This is where Houston Black lives and where the foundation story is real.
- Far south Bexar — South Texas Plains and coastal-influenced soils. Different again.
And by raw mapped acreage the single most extensive soil in the county isn't Houston Black at all — it's Eckrant, the shallow-over-limestone soil, at roughly 112,000 acres against Houston Black's 75,000. Neither one "is" San Antonio. That is precisely why a blanket claim about "San Antonio soil" is worth nothing, and your particular lot is worth everything.
Computed from USDA NRCS Soil Data Access (SSURGO), survey area TX029 (Bexar County)
And it doesn't stop at the county line
The same band runs through every county around here. Ranked by the share of mapped soil in the USDA's High or Very High shrink-swell classes:
Computed from USDA NRCS SSURGO as the share of rated acreage whose maximum horizon linear extensibility is 6% or greater, weighted by component percentage — one defensible aggregation of several, so treat these as approximate. The USDA sets the classes by linear extensibility: Low under 3%, Moderate 3–6%, High 6–9%, Very High 9% and above. Houston Black in Bexar returns linear extensibility from 7.5% up to 17% — High to Very High — with a plasticity index of 44–55.
Comal, Wilson, Atascosa, Medina, Hays and Kendall all carry their own mix — Comal and Kendall lean toward the limestone side of the escarpment, Wilson and Atascosa toward the southern plains. The rule that actually travels is not the county. It's which side of the escarpment your lot sits on, and how far.
A home inspection is not a soil investigation, and nothing in a normal Texas home purchase requires anyone to look at the ground. Not the inspector, not the appraiser, not the lender. That isn't a scandal — it's just not in anybody's scope.
02 — Why it's a lemon
There's a lemon law for cars. There isn't one for dirt.
A car lemon looks perfect on the lot. The problem is under the hood, you can't see it on the test drive, and by the time it surfaces, it's yours.
This looks perfect at the showing. The problem is under the slab, you can't see it at the walkthrough, and by the time it surfaces, it's yours.
And the lemon isn't the house. Plenty of well-built houses sit on ground that will fight them for thirty years. The lemon is the dirt — which is why the smart money looks at the lot before it falls in love with the kitchen.
03 — The road is the tell
They didn't put I-35 there by accident
The highway traces a geologic boundary. West of it the ground is largely limestone — hard, shallow, stubborn. East of it the ground turns to deep clay that moves with the weather. Drag the marker and watch the house cross over.
- Where you are
- West of the seam
- What's under the slab
- Shallow soil over limestone
- How much it moves
- Low
04 — The eight reasons
Three you inherit. Three you control. Two somebody chose.
Eight things move a foundation here. They aren't equal, and they aren't all your problem — which is the good news buried in this page.
Three you inherit · you can't change these, only know them
The dirt is alive
A clay that expands when it takes on water and contracts when it loses it. Not settling — breathing, on a seasonal cycle, indefinitely.
You're near a seam
The corridor runs along a geologic boundary. Which side of it you're on, and how far, changes what's under you more than which city you're in.
Texas doesn't rain, it binges
Long dry spells broken by heavy rain, over and over. It isn't the drought or the downpour that breaks slabs. It's the swing between them.
Three you control · all three are water
Your trees are drinking your house
Big roots near the slab pull moisture out of the soil on one side. That corner drops while the rest of the house stays where it was.
Water that won't leave
Ground sloping toward the house, no gutters, downspouts dumping at the corner. You get a soaked edge and a dry middle — the worst possible combination.
The leak you can't see
A supply or sewer line under the slab, wetting one zone for months or years. Invisible from the surface, and one of the most common real causes.
Two somebody chose · before you ever saw the place
How it was built
The slab design, the soil assumption behind that design, and whether the lot was cut down to native ground or built up on fill.
How it's been lived in
Whether anyone kept moisture steady through the dry months, or let the ground bake on one side while the sprinkler soaked the other.
05 — Lot to lot
Your neighbor is fine. You're not.
Two houses. Same builder, same floor plan, same month. Sixty feet apart on quarter-acre lots. One of them is fine at year ten and one of them isn't, and this is the part almost nobody knows to ask about.
House A
Listed first. Bigger back yard. That is all the curb tells you.
House B
Listed three weeks later. Nicer porch view. The curb tells you no more here.
Why two lots on one street disagree
- Soil maps aren't lot maps. The published soil surveys are drawn at a scale far coarser than a quarter-acre lot. A single mapped unit routinely contains more than one soil.
- Depth to rock changes fast. How much clay sits between the slab and something solid can differ substantially over a short distance.
- Old water finds a way. A filled-in drainage path, a creek terrace, a low spot — invisible once the sod goes down.
- Subdivisions get graded. Mass grading cuts some lots down and builds others up. One house ends up on native ground and the one across the street on several feet of fill.
- And nobody drilled your lot. This is the one that should stop you.
The Texas Section of the American Society of Civil Engineers recommends, as a minimum for a subdivision, borings "at maximum 300 foot centers" — and that's the minimum for ground believed to be uniform. It recommends borings at least 20 feet deep. Do the arithmetic: at 300-foot centres each boring covers about two acres. On quarter-acre lots that is roughly eight houses per boring, and more on the smaller lots common around here. The document itself says non-uniform conditions require more.
Texas Section ASCE, Recommended Practice for the Design of Residential Foundations, Version 2, adopted 4 October 2007 — verified against the document 2026-08-30
And the free soil map can't settle it either
The instinct is to look your address up on the government soil map. It's a good instinct and it will not answer this question, for a reason the USDA states outright.
County soil surveys have a minimum mapped shape of 1.5 to 10 acres. A typical tract lot is a fifth of an acre — between seven and fifty times smaller than the smallest area the map is capable of drawing. The USDA also says that siting individual building lots calls for an Order 1 survey, and that Order 1 surveys "are treated as special types of onsite investigations and are not part of the official soil survey."
And zooming in doesn't help. The manual is blunt: "The scale used to make the survey is the scale that must be used to display the mapping." Magnifying a map past the scale it was drawn at is the error, not the fix.
USDA-NRCS Soil Survey Manual, Handbook 18, Chapter 4
- "Complex" means the map gave up. A soil complex is, by definition, two or more dissimilar soils that cannot be separated at the mapping scale. If your map unit says complex, it is formally admitting it can't answer a lot-level question.
- Unnamed soils are allowed inside every shape. The manual says "virtually every delineation of a map unit includes areas of soil components… not identified in the name of the map unit" — up to about 15 percent of a dissimilar limiting soil that never appears on the label.
- One soil name, five times the depth to rock. Eckrant — the largest-acreage soil in Bexar County — is officially defined with bedrock anywhere from 4 to 20 inches down. Same name, same colour on the map, wildly different ground.
- The clay builds its own hills. Blackland vertisols churn themselves into mounds and hollows on a 10-to-24-foot cycle. On undisturbed ground the USDA records knolls sitting 3 to 18 inches higher than the hollows beside them; grading a subdivision flattens the surface but not the soil profile beneath it. A single lot spans several complete cycles — so the variation isn't only house to house, it's corner to corner on your own property.
USDA-NRCS Official Series Descriptions — Eckrant, Houston Black
The Texas engineering guidance states plainly that "fill may exist between borings or be undetected during the geotechnical investigation" — and that fill is sometimes placed after the investigation is finished.
This is the argument for looking at the specific lot rather than the general area — the plat, the grading, the drainage, and where the water used to go before anybody built here.
05b — The concrete you can read from the street
Your driveway is a soil gauge, not a foundation report
A cracked driveway is weak evidence about the house. It is strong evidence about the dirt and the water. Read it that way and it is genuinely useful. Read it as a foundation report and it will mislead you in both directions.
This is the one part of the inspection you can do from the public street, before you knock on a door, with nobody's permission. So it's worth knowing what it actually means.
Why the concrete outside moves before the house does
Weight holds soil down. The engineering guidance says it directly: "Lightly loaded foundation components, such as concrete flatwork, pavements, and building slab-on-grade floors, are impacted more by expansive soil volumetric changes than are heavily loaded foundation components." On the same clay, the driveway is expected to react more than the loaded parts of the house.
They're also built to completely different rules. A county driveway-approach specification calls for a 5-inch slab with #3 bar at 12 inches, on two inches of base. Sidewalks, four inches. No soil test. No engineer of record. No post-tensioning. A house foundation on this clay requires a geotechnical investigation first, and plans that "shall be signed and sealed by the engineer of record, and be specific for each site or lot location."
Comparing a cracked driveway to a cracked wall is comparing an unengineered slab to an engineered one.
Foundation Performance Association FPA-SC-01-0 · Bexar County driveway approach specification · Texas Section ASCE Recommended Practice, §§4.3.3 and 5.5.1
And concrete cracks anyway
The ready-mix industry's own practice sheet: "All concrete has a tendency to crack and it is not possible to produce completely crack-free concrete," and "Wire mesh and reinforcement in slabs cannot prevent cracking."
Those grooves cut into a walk are there for exactly this reason. "Joints are simply pre-planned cracks." The rule of thumb is a joint every 24 to 36 times the slab thickness — about ten feet on a four-inch slab, fifteen feet maximum. The American Concrete Institute puts it bluntly: without adequate joints, "the concrete will make its own joints by cracking."
A lifted slab edge does not require any soil movement at all. It's called curling — "the distortion of a slab panel into a curved shape by upward or downward bending of the edges and corners at joints or cracks," caused by moisture and temperature differences between the top and bottom of the slab. "Thin slabs and long joint spacing tend to increase curling." Thin walk, long runs between joints, lifted corners: that is the concrete behaving as concrete.
NRMCA CIP 4 · CIP 6, joints · CIP 19, curling · ACI 224R-01 §3.5.3
What flatwork does tell you — and it is the useful part
The one published statement from a foundation engineering association on exactly this question points at the soil, not the house: "Horizontal movement of flatwork, called 'walking,' may indicate movement due to expansive soils. Vertical movement of flatwork usually indicates soil activity."
Look at what both sentences are about. Soil.
The concrete is not reporting on your foundation. It is acting on it — by deciding where the water goes. Guidance for owners is specific: "All paving and Flatwork should drain away from the Foundation. If less than 10' from a Foundation, and especially for sites located in Expansive Soil, the Subcommittee recommends using a slope of 2% away from Foundation (2" Drop per 8')." It adds the part people leave out: if 2% is impractical, "lower slopes such as 1% or lower may be used, or a side slope can be used to drain to the adjacent grade."
And: "Paving and Flatwork joints next to your Foundation should be sealed." The named failure mode is a slab that pulls away and lets water in at the edge of the building — which is the mechanism that actually reaches your slab.
Foundation Performance Association FPA-SC-20-0, §§2.1.3–2.1.4, and FPA-SC-02-0
What it does not tell you
- Whether the foundation has moved. Nothing in the reviewed standards, codes or state rules treats flatwork condition as an indicator of foundation performance.
- That the house is fine because the concrete looks perfect. No source supports that inference either. Soil under a slab is usually wetter and changes more slowly than soil out in the open.
- Which side moved, or which way. A gap does not say whether something heaved or dropped. Without a benchmark, contours alone can't tell you.
- How much. There is no published conversion from driveway displacement to house-slab displacement. A number quoted that way would be invented.
- What a crack width means. No Texas standard sets a crack-width threshold for flatwork. Any "under an eighth is cosmetic, over a quarter is structural" rule applied to a driveway is made up.
- How old it is, or whether it's still moving. That needs repeat surveys over time, not one look.
- Whether your porch or patio is even part of the foundation. That varies house to house and has to be determined on the property.
The instinct is to eyeball the house against the curb. Foundation engineers are told not to: "trees, fire hydrants, curbs, light stanchions, manhole covers, etc., have been shown to move significantly relative to Foundations." The curb is sitting on the same clay. It is not a fixed reference.
A gap in how the transaction is built
A Texas home inspector is not required to inspect "concrete flatwork such as driveways, sidewalks, walkways, paving stones or patios" — except as it relates to slope and drainage. That isn't anyone's oversight; it's how the standards are written.
So a report that says nothing about your driveway has not cleared your driveway. The only officially recognised inspection interest in that concrete is which way the water runs off it.
22 TAC §535.227(d)(1)(G) and §535.228(b)(2)(A) — TREC Standards of Practice
And in San Antonio, that sidewalk is your problem
City Code Sec. 29-11(a) puts the duty on the abutting property owner to "keep the sidewalks, parkway, curb and driveway abutting said property in a good and safe condition and free from any defects and hazards." Sec. 29-11(b) gives 30 days from written notice to fix it. Sec. 29-11(c) makes the owner "primarily liable" for injuries and requires the owner to "indemnify and save harmless the city" — and says that applies whether or not the city was ever notified.
For scale: the city has roughly 6,000 miles of sidewalk, and its Fiscal Year 2026 budget funds repair of 11 miles. "The city will get to it" is not a plan.
San Antonio City Code Sec. 29-11 and Sec. 1-5. How often the city actually issues a repair notice is not published anywhere we could confirm — the legal authority is verified, the enforcement frequency is not.
06 — The walk-around
Seventeen things, about twenty minutes
Outside first, then inside, then the paperwork. Tap anything you actually see. This does not diagnose your foundation and it isn't trying to — it tells you whether it's worth paying someone qualified to look.
This is not an inspection. It does not diagnose or evaluate anything, and it cannot tell you whether your foundation is sound. It exists to help you decide whether to ask a licensed professional. Do not rely on it to decide that you don't need to.
Nothing flagged yet
Walk the outside first. Take your time — most of these are easier to see than people expect.
07 — What it means
Cosmetic, or catastrophic?
Most cracks are not an emergency. Some are. The difference is mostly about where the crack is and what it went through to get there — not how ugly it looks.
Mortar, or the brick itself?
This is the distinction most people never learn. Mortar is the softer, sacrificial part of a masonry wall — it's designed to give first. A crack that follows the mortar joints, stepping along them, is the wall doing roughly what it's built to do under movement.
A crack that runs straight through the brick or stone units themselves is a different signal. The movement found something stronger than the mortar and went through it anyway.
Neither pattern is a verdict. Brick veneer is a skin hung on the outside of the house, not the structure holding it up — so masonry cracking is a symptom to be read, not a diagnosis on its own.
The numbers an engineer is actually working to
You can't measure these from the sidewalk, but knowing they exist changes what you ask for. Texas engineers work to published figures, and they are narrower than most people guess.
Foundation Performance Association, FPA-SC-13-1, Guidelines for the Evaluation of Foundation Movement for Residential and Other Low-Rise Buildings, 11 April 2015 — the current revision; the association lists the 2007 edition as superseded — quoted verbatim: "Tilt be less than or equal to one percent (1%) over the entire length, width, or diagonal of the Foundation" and "the onset of excessive distress in the Superstructure appears to occur when Deflection exceeds the span divided by 240 to 480." Written specifically for Texas. Verified against the document 2026-08-30. Important: the Texas Section ASCE guidelines state plainly that they are "not intended to be Standards, but are guidelines only, reflecting the engineering opinions and practices of the committee." The Foundation Performance Association document carries its own disclaimer of standard status. Both are professional guidance, not law, and no rule obliges anyone to meet them.
The decoder
These are patterns described in published engineering and masonry literature. They are descriptions of patterns, not findings about your house. The same crack can have several causes, and only a licensed professional engineer who has actually looked at your property can say which one applies. Use this to decide whether to call someone — never to decide that you don't need to. Confirm anything that matters against the underlying documents and a licensed professional.
| What you see | What published engineering guidance associates it with | How that guidance treats it |
|---|---|---|
| Hairline cracks in the mortar joints only, never through a brick | Masonry guidance describes the mortar joint as the deliberately sacrificial element — far weaker than the brick, and designed to crack first. | Normal |
| A crack running through several brick units instead of around them | Guidance treats a crack that takes the path through the unit rather than the joint as a different order of force, and as a referral trigger. | Engineer |
| Any masonry crack wider than about 2 mm (0.075 in) | The masonry industry's own structural-referral threshold — stricter than several other published schemes. | Engineer |
| Stair-step cracking directly above the foundation | The classic differential-movement signature. | Engineer |
| A diagonal crack running between two windows or doors | Masonry guidance groups stepped and diagonal patterns together as structural indicators — a diagonal crack between openings is not treated as a lesser signal than stair-stepping. | Engineer |
| A crack wider at one end, tapering to nothing | Tapering points toward bending or settlement, widest where displacement is greatest. | Watch |
| Full-height vertical crack of uniform width, mid-wall | Thermal movement — catalogued by Texas engineers as commonly mistaken for foundation failure. Uniform width is the tell. | Cosmetic |
| Short horizontal cracks at a lintel, often with rust staining | Forensic engineers catalogue this pattern as rust jacking — corroding lintel steel expanding and lifting the brick — and list it among distress commonly attributed to foundations by mistake. | Watch |
| Brick veneer bulging or leaning out of plane | Outranks any crack as a safety signal. Sight along the wall from a corner. | Urgent |
| A vertical expansion joint that changes thickness top to bottom | A free diagnostic almost nobody uses — a possible sign of excessive movement. | Watch |
| Fresh or colour-matched repointing | Someone covered past movement. Spray it with water — new mortar often dries a different shade. Ask why it was done. | Watch |
| Diagonal cracks in interior drywall at door and window corners | The engineering body's sharpest interior indicator of excessive movement. | Engineer |
| More than 1/4 inch of floor slope over four feet | A published trigger to call an engineer — a screening cue, not a verdict. Four feet is too short a span to mean much alone. | Engineer |
Compiled from masonry-industry technical guidance, Texas Section ASCE and Foundation Performance Association documents. Full sourcing in the research file.
Judge it against the age of the house
Published guidance grades expectations by age, and it is about cracking that has opened since the house was built: nothing beyond hairline under ten years, up to about an eighth of an inch after that. Exceeding it is a reason to ask, not a finding — and read it alongside the list below, because several things that look alarming in a new house are shrinkage rather than movement.
What is actually normal — and frightens people for nothing
- Nail pops in walls and ceilings. Wood framing shrinking. Engineers advise waiting roughly two years before repairing.
- Crown moulding separating in a new build, and drywall tape lifting at seams and corner beads. Same cause, same wait.
- Grout-line cracks in a new home's tile — the slab kept shrinking after the tile went down.
- A crack in one tile that does not continue into its neighbours and has no mortar cracking. Cracks are inherent in the material.
- Surface cracks in a post-tensioned slab before the tendons are stressed. They typically close afterwards.
- Almost any hairline cracking in a house under about two years old. Soils normally settle down in the first year or two.
- Hairline and corner cracks in stucco. The stucco industry's own policy tells owners to expect exactly that.
Foundation Performance Association FPA-SC-03-1 and published industry crack-policy documents
08 — Who to call
The diagnosis and the sale shouldn’t share a paycheck
If you take one thing from this page, take this: the person who decides whether you need a repair should not be the person who gets paid for the repair.
Free foundation inspections are real, and they're free for a reason. That isn't an accusation about anyone's honesty — it's arithmetic. A company that sells piers is a company whose inspector's job description includes finding work. Even scrupulous people inside that structure are being asked to grade their own exam.
That person is a licensed professional engineer. They come out, they measure, they write it down, and they put their license on it. If the answer is "your house is fine," they get paid the same as if the answer is "your house needs forty piers."
What that gets you
- A written, stamped report — a document you can hand to a seller, a buyer, a lender, or a court.
- An actual measurement of how the floor sits, not an impression from walking around.
- A recommendation on whether to test the plumbing, which is a common hidden cause.
- Independence. Nothing in the report is trying to sell you the fix.
And what a home inspection is not
A Texas home inspector must give you a written opinion on whether the foundation appears to be performing. That part is required — and it is based on visible conditions and symptoms.
What it is not is an engineering evaluation. The Texas Board of Professional Engineers settled this in a formal advisory opinion: analyzing the cause of a condition, recommending a repair, or giving any other expert engineering opinion about a foundation is the practice of engineering, and "TREC licensed inspectors are not permitted to provide an engineering opinion on a foundation unless they also hold a PE license."
So the inspector tells you what can be seen. Why it is moving, and what to do about it, is a different licence and a different scope of work. That is not a knock on inspectors — it is the line the state drew, and a good one will tell you the same thing. If the answer matters to your decision, hire for the answer you need.
Texas Board of Professional Engineers, Engineering Advisory Opinion Request 43, February 2018 — document fetched and read in full 2026-08-31, quoted verbatim. The same opinion concludes, equally verbatim, that "a TREC licensed inspector who conducts a visual real estate inspection in conformance with the TREC Standards of Practice does not engage in the practice of engineering." Cross-referenced to the TREC Standards of Practice, 22 TAC §535.228(a)(1)(A) and §535.227(d)(3)(E) and (d)(7).
Plenty of foundation repair companies do good work, and some retain engineers themselves. There is no verified Texas Attorney General alert, enforcement action, or news investigation establishing a pattern of misconduct in this industry, and this page doesn't allege one. The argument is narrower and survives all of that: diagnosis and sales shouldn't share a paycheck.
Now the part almost nobody knows
Texas does not license foundation repair contractors. At all.
Most people assume that a job this consequential — lifting a house — must require a state licence, the way plumbing and electrical work do. It doesn't. There is no state licensing program for foundation repair, underpinning, general contracting, or residential construction contracting. And the Occupations Code expressly exempts repairing a private dwelling from engineering licensure.
In the transaction where someone tells you your house needs forty thousand dollars of structural work, the contractor proposing that work holds no state licence at all. The engineer is the licensed, regulated and disciplinable party — and hiring one is optional. That isn't an accusation against anybody. It's the structure of the law, and it's why "who is telling me this, and what happens to them if they're wrong" is the most useful question you can ask.
There's a narrow exception worth knowing: the private-dwelling exemption is lifted for engineering design of a foundation on expansive soil — but conditionally, and it snaps back where the work meets the residential code as the local jurisdiction applies it. It's a real carve-out and it is not the blanket protection it sounds like.
Where the state leaves a gap, San Antonio partly fills it: the city requires a permit for residential foundation repair and requires the work be designed by, or performed under the guidance of, a Texas-licensed professional engineer. So in San Antonio the permit record is the closest thing to a licensing check you get — and pulling it is free.
An engineer with nothing to sell can tell you to do less. The Texas guidance explicitly contemplates that "an owner may choose to perform periodic cosmetic repairs and door adjustments, rather than comprehensive foundation underpinning." That option only reaches you from someone who isn't paid by the pier. The same body publishes a document titled, in as many words, "The Presence of Damage Does Not Automatically Indicate Negligence." An honest evaluation often ends in "leave it alone."
Texas requires the firm to be registered, not only the individual. An engineer's personal licence isn't sufficient on its own — verify the engineer and the business entity on the state board's public rosters. Both are free.
And one myth in the other direction: the seal everyone is told to demand is discretionary on an evaluation report, not mandatory. The rule requires printed name, date, signature and "P.E." A missing seal is not by itself a red flag.
This may not fit your option period. Geotechnical and engineering work is scheduled, not instant, and Texas has no statutory option period — yours is only as long as you negotiated for. If the ground matters to you, negotiate that time before you need it.
Ask for a Level B. Say it in those words.
The Texas Section ASCE guidelines define three levels of foundation investigation, and the difference decides whether you get an opinion or a measurement.
| Level | What you get |
|---|---|
| A | First impressions. The standard says it must be labelled as such and must not imply anything more was done. This is a walk-through. |
| B | Adds a determination of relative floor elevations — an actual survey of how the slab sits. This is the one you want. |
| C | Deeper still, including soil investigation. |
Texas Section ASCE, Guidelines for the Evaluation and Repair of Residential Foundations, Version 2
The City of San Antonio requires a permit for all residential foundation repair, and requires the work be designed by or performed under the guidance of a Texas-licensed professional engineer. So a permit record is a paper trail on any repair that was done properly — and its absence tells you something too. The city's own bulletin warns: "A double fee will be assessed for failure to apply and obtain a permit before starting work."
City of San Antonio Development Services, Information Bulletin 172 — Residential and Commercial Foundation Repair Permits, revised 7 April 2025
What it costs, and why nobody will tell you
Here is the honest finding: no San Antonio engineering firm we could find publishes a price at all. The standard answer on a local firm's own site is that fees vary by location and foundation size. You are expected to call.
Cost-estimate websites publish wildly different ranges for this — they contradict each other, and we could not determine how any of them are produced or whether any reflects this market. This page is not going to invent an average. Call two or three firms, describe your house, and get your own quotes. That is the only number that means anything.
This page does not recommend, rank, or refer any particular firm. No engineer, warranty company, or foundation repair contractor pays me anything for this. If that ever changes, this page will say so.
09 — What you can do
Cheap things that actually work
Most of what protects a foundation here costs very little. It's just nobody tells you to do it.
The whole game is keeping the moisture in the ground steady. Not wet. Not dry. Steady. Clay doesn't mind being damp and it doesn't mind being dry — it minds the change.
The watering problem, and the way through it
Here's the bind: the ground wants steady moisture, summer takes it away, and the obvious fix — running the sprinklers — is exactly what gets restricted when it's driest.
There is a way through, and almost every article about it gets the detail wrong.
Standard foundation advice says "run a soaker hose along the slab." In San Antonio right now, a soaker hose is not hand watering. It is grouped with irrigation systems and sprinklers — once a week, on the day assigned by your address, 5–10 a.m. or 9 p.m.–midnight. The thing nearly everyone recommends is the thing that's restricted.
What is unrestricted here: a hand-held hose. Verbatim: "Watering with a hand-held hose is allowed any time on any day." It has to be physically held by a person and fitted with a shut-off nozzle. That's the lawful path, and it's the one nobody mentions.
Verified live 2026-08-30 — SAWS Stage 2 Watering Rules. Stage 2 was in effect that day, with the Edwards J-17 index well at 644.8 ft.
The SAWS year-round page says "Hand watering with a hand-held hose, soaker hose or bucket is permitted any time of day." The Stage 2 page says a soaker hose is restricted irrigation. Both were live on the same day. Because a stage is in effect the restrictive one governs — but a reader who lands on the year-round page first walks away with the wrong answer.
Two things nobody tells you before you read the table
Several cities in this corridor do have a foundation-watering carve-out — and it appears zero times on their own drought-restriction pages. It lives in the municipal ordinance. In this sweep only one city answered the question in plain English on its website; two others had a real carve-out buried in code where no resident would find it, and the rest had none at all.
So "my city's website doesn't mention foundations" does not mean there is no rule. It means you have not read the ordinance yet.
People assume the two are treated alike. They are frequently treated as opposites. Several cities here classify a soaker hose as a sprinkler — once a week, on your assigned day — while allowing drip irrigation any day and any time. One city defines a soaker by whether it throws "a fine spray in the air." Several others publish no soaker rule at all, at any stage, so the honest answer there is that nobody knows.
Since a soaker along the slab is the single most commonly recommended foundation practice, this is the detail most likely to put someone on the wrong side of an ordinance.
Your utility, not your neighbor's
These rules are set utility by utility and they genuinely disagree. Two houses fifteen minutes apart can have opposite rules. Find yours.
| Utility | Hand-held hose | Soaker / drip | Mentions foundations? |
|---|---|---|---|
| SAWS San Antonio | Any time, any day | Restricted. Soaker counts as irrigation, once a week. Drip Mon/Fri only | No — no guidance and no foundation variance category |
| Austin Water | Any time, any day | Drip and hose-end on a two-day schedule | Yes — water it on your assigned day, sprinklers about 18 inches out |
| New Braunfels NBU | Any day, but only before 10 a.m. and after 8 p.m. | Same terms, if it doesn't spray into the air | Yes, codified — up to two hours any day during watering times, soaker or drip within 24 inches |
| San Marcos | Any day before 10 a.m. or after 8 p.m. | One day a week | Yes — strictest in the corridor. Foundation watering by any method, one day per week |
| Buda Stage 3 | Restricted — once-a-week schedule, never 11 a.m.–7 p.m. | Same as hand watering: once a week, same hours | Yes — and it is the most permissive in the corridor. Foundation watering is "any day and at any time", with saturation causing pooling or runoff prohibited |
| Kyle | 7 p.m.–10 a.m. any day, shut-off nozzle required | On your designated day | Yes — soaker around foundations once a week on any day, named for structural protection |
| Cibolo no stage published | Not published. The city page restricts irrigation systems only and is silent on hand watering | Not published | No — and part of Cibolo is served by Green Valley SUD instead, whose rules are far stricter |
| Georgetown | Any day, any time | Drip only on your day, inside the 14-hour window | No |
| Round Rock | Any time, any day | Not exempt — the city says so in capitals on its own page | Yes — an allowed use, on the watering schedule |
| Live Oak two conflicting official versions | Any time, any day — both versions agree | Do not rely on this row — call the city. The city web page says soaker once a week on your day, 5–10 a.m. or 9 p.m.–midnight, drip Mon/Fri. The city's own Stages 1–4 PDF says every other week, 7–11 a.m. or 7–11 p.m., drip Mon/Wed/Fri. Both are live today | Yes — but only in the ordinance. Code §23-16(b) lets a soaker be used "for foundation watering on any day of the week during specified times" — escaping the weekly day limit, not the hours |
| Universal City Stage 3 | Any time — only if attended. The city warns an "unattended handheld hose will be considered same as sprinklers" | Soaker = sprinkler, once a week. Drip or 5-gal bucket Mon/Wed/Fri | Yes, in ordinance §2-10-106 — bucket, hand-held hose, soaker or drip "immediately next to a concrete foundation". Note the window is narrower than the stage's own watering hours |
| Pflugerville year-round | Any day, any time, shutoff nozzle required | Drip any day/any time. Soaker not addressed for the current stage | Yes — and the only one that says so plainly on its website: "Watering the ground around a foundation to prevent cracking is exempt from drought restrictions." Ordinance limits it to the foundation footprint — expressly not driveways, sidewalks, patios or carports |
| La Vernia Stage 3 | Not free. Designated address day and hours only | Drip on your day only. No soaker rule published at all | No — "foundation" appears nowhere in either 2026 plan |
| Boerne Stage 2 | Any time — ordinance adds a shutoff-nozzle condition the city's summary page omits | Drip any time if properly functioning. No residential soaker rule | No |
| Hutto Stage 1, voluntary | Any time, any day | Drip any time. No soaker rule published | No — hand-held and drip are fine, but on the general allowance, not a foundation rule |
| Selma no stage declared | Any time, any day — but the hose must be attended | Drip any time. No soaker rule published | No. Year-round rule still bans sprinklers 10 a.m.–8 p.m. |
| Santa Clara served by Green Valley SUD | See Green Valley SUD — the city runs no water utility of its own | See Green Valley SUD | No |
| Schertz | Any time | Drip any time — the only one in the corridor exempting drip outright | No |
| Green Valley SUD parts of Guadalupe, Comal, Bexar | No anytime exemption. Designated days and hours like everything else | Same designated-day rule | No |
Every row read off that utility's own page on 30 August 2026. Sources: SAWS · Austin Water · NBU · San Marcos · Kyle · Georgetown · Round Rock · Schertz · Green Valley SUD · Buda · Cibolo
Drought stages change, sometimes on a few days' notice. This was accurate on 30 August 2026 and it is not a substitute for checking. Two utilities were deliberately left out because their current stage could not be confirmed from their own published text, and one city publishes no hand-watering rule at all. If you're served by a small water supply corporation, a MUD or a WCID, none of the above is yours — part of Buda is served by a separate water control and improvement district, and part of Cibolo is served by Green Valley SUD rather than by the city.
Some cities simply do not publish this in any readable form. Seguin's water department page states no current stage at all, and its drought contingency plan is posted as a scanned image with no searchable text. Cibolo publishes hours for irrigation systems and a Sunday sprinkler ban, but nothing about hand watering. Third-party "water restriction" websites will cheerfully give you a stage and a fine amount for both — we could not confirm those against either city, so they are deliberately absent here. For those areas, call your utility. Do not trust a scraper with a number that could cost you a fine.
Three more were checked and deliberately left off the table because their own published rules could not settle the question: Converse, whose water page and council designation contradict each other and both are live; Marion, which has an adopted drought ordinance but publishes no current stage anywhere; and Springs Hill Water Supply Corporation, which publishes a six-stage plan but never says which stage is active. If one of those serves you, calling is the only reliable answer. Look up your provider before you turn on a hose.
The Edwards Aquifer Authority publishes critical-period stages too, and today both it and SAWS read Stage 2 — but the Authority's stages govern permit-holder pumping, not your garden hose. It states plainly that it regulates well owners holding withdrawal permits, not the public. Your watering rules come from your utility.
You can absolutely overdo this. Over-watering causes heave and can destroy the soil's bearing capacity — the opposite failure, equally expensive. Apply water lightly and evenly, roughly 12 to 24 inches out from the slab. And never pour water into the gap where soil has pulled away from the foundation. Even and moderate. Never soaked.
You do not have to take that from this page. One city in the corridor writes the same limit into its own drought ordinance: foundation watering is permitted any day and at any time — but "saturation to the point it causes pooling in the yard or runoff is prohibited." A municipality that is otherwise rationing water to one day a week will let you water a foundation whenever you like, right up until it puddles. That is the line.
In practice: a slow pass with the hose along each side of the house, enough to darken the top inch or two of soil in a band roughly 12 to 24 inches wide, then stop. If water pools, stands or runs off, you have already gone too far. Little and often beats a lot occasionally — the goal is to avoid the swing, not to soak the ground. Never run water into an open crack where the soil has pulled away from the slab.
The rest of the cheap list
- Gutters, and where they let go. A downspout emptying beside the foundation is a sprinkler pointed at the one place you don't want one. Extensions are cheap.
- Ground that slopes away. Water should leave the house, not pool against it.
- Watch the beds. Planting beds and mulch banked against the slab hold water right where it does the most.
- Know where the trees are. The Post-Tensioning Institute's design manual gives the rule most Texas field lore repeats without attribution: trees planted within half their mature height of the foundation edge have caused differential movement. Measure by what the tree will become, not what it is.
- Don't reach for the chainsaw. Removing a big mature tree near a slab can let the dried-out soil rehydrate and heave the foundation upward. The current Texas ASCE guidance (Version 3, 2022) does not compare root barriers to removal at all — it says only that "root barriers or periodic root pruning may mitigate the effects of vegetation," and that barrier installation "may negatively affect the vegetation," recommending you contact an experienced arborist. Taking the tree out is not automatically the safe move. Ask the engineer first.
- Read your water meter — the free two-hour test. Turn off everything that uses water, note the meter, do not flush for two hours, read it again. Movement means water is leaving the system. It will not tell you where — a running toilet looks identical to a slab leak — but it costs nothing. The formal version is a static test: the drain system plugged, filled and held under a head of water for at least fifteen minutes. The required head is set by the code your city has adopted, not by a national number — San Antonio's adopted amendment calls for 3.5 feet where the base International Plumbing Code says ten. Ask the plumber which standard they are testing to.
- Open the irrigation valve boxes and the meter box and look for standing water. Five minutes, free, and a surprisingly common find. Lift the lid with a tool and from the far side rather than with bare hands — those boxes are cool, damp and dark, which is exactly what a snake is looking for in a South Texas summer.
- Extend every downspout to discharge at least five feet out — then check where that water actually goes. A downspout draining into a low spot that runs back toward the house has solved nothing.
- Turn every sprinkler head away from the slab and stop overspray onto the foundation.
- Fix the small leaks: dripping outdoor faucets, the air-conditioning condensate and overflow lines, leaking irrigation valves. Each one puts water in a single spot, all day, for years.
- If work gets done, test the plumbing after. The Texas ASCE repair guidelines call for supply and sanitary drain lines to be tested for leaks when a foundation is jacked or lifted — lifting a slab can break the pipes running through it.
- Photograph and date your cracks. Costs nothing, and it turns "I think it's worse" into evidence.
09b — The warranty question
"Lifetime transferable" is doing a lot of work in that sentence
A repaired foundation with live, transferable, independently-backed coverage is a materially different asset from an unrepaired one — or from one whose warranty is now worthless. That's a pricing argument, not just a disclosure item.
Which is why the paperwork deserves more than a glance. Three things go wrong, and all three are invisible until you ask.
1. The warranty may never have included transfer at all
Transferability is frequently an upgrade the original homeowner had to buy, sometimes for a four-figure sum, at the time of the repair. Plenty of "lifetime" warranties in the field were never bought with that feature — and they simply end when the house sells. The word "lifetime" refers to the company's relationship with the person who paid, not to the house.
2. It may only transfer once
Some transfer exactly once, to the immediate next owner. Others allow unlimited transfers. If your seller is already the second owner, a once-only warranty was spent before you ever saw the listing.
3. The company has to still exist
"Is this warranty backed by an independent trust, or only by the company's continued existence?"
Ask it exactly that way, because the answer is not the same from company to company. Some warranty programs in this market are trust-backed: their published terms provide that an independent warranty trust steps in and upholds coverage if the original dealer becomes inactive. Others describe no third-party backing at all — the paper is only as good as the company still being there to honour it.
And foundation repair companies do go out of business, including long-established ones. When that happens a company-backed "lifetime transferable warranty" can become worth nothing overnight, while a trust-backed one may not. That single difference can outweigh every other term in the document — and it is invisible unless you go looking.
So go looking. In your own paperwork, find the language about what happens if the issuing company is no longer active. If there isn't any, you already know which kind you have.
Note too that coverage terms can differ dealer to dealer inside the same brand, so the brand name on the certificate doesn't settle it. The document does.
There is no industry standard. That is the finding.
We read the published warranty terms and transfer forms of a dozen companies operating in this market. They do not agree on anything that matters:
| What varies | What we actually found in published terms |
|---|---|
| Transfer fee | $0, $100, $150, $200, $250, $500. These do not cluster around anything. The "$75 to $300" figure repeated all over the internet is uncited and is contradicted at both ends. |
| Deadline | Commonly 30 days — but measured variously from the sale, from title transfer, or from the purchase of the home. One company waives the fee entirely if the house sells within 180 days of the work. Some publish no deadline at all. |
| Miss the deadline | Genuinely opposite outcomes. Some publish that an untransferred warranty "will expire and become non-transferable" and that expired warranties will not be honored. Another publishes the reverse in as many words: "we never cancel a warranty because it was not transferred." |
| Formalities | Some require notarization. Some require a specific form. Two of the largest names in this market publish transferability with no deadline, no fee and no form anywhere on their sites. |
| Who may claim | At least one restricts claims to the current property owner — so an unfinished transfer can leave nobody able to file. |
Compiled 2026-08-30 from companies' own published warranty pages and transfer forms. Terms change; the document attached to your house governs, not this table.
It doesn't mean the house will never move. One published warranty commits to adjusting a piling at no charge if it settles more than 1/4" over a 5-foot span — while expressly excluding cosmetic repairs and the tunneling needed to reach the pilings. So the concrete is covered and the drywall, paint and trim it wrecked on the way are yours.
And using the warranty is not necessarily free: more than one company publishes a $75 service fee due when you book a warranty visit.
What to actually ask for
- The warranty document itself, not a summary and not the seller's memory of it.
- Whether it is transferable, and critically how many transfers remain — not merely whether the feature exists. If it transfers only once and your seller already used it, there is nothing left for you. Get the remaining count in writing.
- The transfer fee, the deadline to file, and precisely what date the clock runs from — closing, funding, or the deed record. Get that in writing, because it decides whether coverage survives.
- Whether transfer requires a re-inspection or an engineer's letter, and who pays for it.
- Whether the backing is a trust or the company.
- What the warranty excludes — cosmetic damage and access tunneling are commonly excluded — and whether there's a service fee to make a claim.
- The current corporate standing of whoever issued it.
The window can be thirty days. The fee can be zero, or five hundred dollars. Two of the biggest names here publish neither. Get the actual document.
The transfer fee and any required testing are ordinary contract items. They can be allocated to either side and paid at closing like anything else. Deal with it in the contract rather than discovering it three weeks after funding, when the filing window may already have closed.
Before anyone tests the plumbing, know this
Under-slab leaks are a genuine driver of foundation movement, so testing the plumbing sounds like an obvious move. It is not a simple one, and this is the part most buyers — and plenty of people in the business — do not know.
On a house you do not own yet, a hydrostatic test requires the owner's written authorization. TREC promulgates a form specifically for it — Form 48-1, Addendum for Authorizing Hydrostatic Testing, effective 1 March 2020 — and TREC's own description of that form says it "addresses who pays for and is responsible for damages from a hydrostatic test, if the parties agree to have one performed."
Read that description again, because it is the warning. The reason a form exists to allocate liability is that the test itself can cause damage. Pressurising an old drain line can create a leak that was not there before — and who owns that problem is then decided by whatever the parties agreed to in writing, or failed to.
TREC Addendum for Authorizing Hydrostatic Testing, Form 48-1, effective 03/01/2020 — description quoted verbatim from TREC, read 30 August 2026. The Texas REALTORS® equivalent is TXR 1949.
There is another way to look at the same pipes: a plumber can run a camera scope through the lines and evaluate them visually, without pressurising anything.
The two methods answer slightly different questions and carry different risks, and the right choice depends on the house, the age of the plumbing, what the seller will agree to, and where you are in the contract. That is a conversation to have with your real estate agent — and, if a test is going to happen, with a licensed plumber — before anything is ordered or signed. What matters is knowing both options exist, and that one of them needs written permission and a liability decision first.
An unmanaged foundation history is a discount. A documented one, with the engineer's letter, the repair records, a warranty you've confirmed is live and transferable, and a current elevation survey, is just information — and it takes the uncertainty — which is what actually costs you money in a negotiation — off the table. Same house. Different number.
10 — The paper trail
What to ask for, and when
If a house has foundation history, that is not automatically bad news. An unmanaged history is bad news. A documented one is just information.
- The seller's disclosure — read what it actually says about repairs, and what it doesn't say.
- Any engineer's letter from a previous evaluation, with the date.
- Repair records, including which company, which method, and how many piers.
- The warranty — and specifically whether it transfers to you, and what it actually covers.
- The post-repair benchmark elevations from the original pier paperwork, and a current floor elevation survey to compare against them. One survey shows the shape of the slab today. Two, years apart, show whether it has moved since the work was done — which is the actual question, and almost nobody asks it.
- Plumbing test results — and read the section below before you order any test yourself.
On the TREC Seller's Disclosure Notice there is no separate foundation-repair box — a repair is disclosed under the combined item "Previous Structural or Roof Repair." And here's the part that matters: neither the TREC form nor the TXR version asks whether a repair carries a warranty, whether that warranty transfers, or who did the work. The form will never hand you that. You have to ask.
TREC Form 55-1, Seller's Disclosure Notice, required under Texas Property Code §5.008 — full text extracted and searched 2026-08-30
The Foundation Performance Association publishes free PDFs written by forensic engineers rather than contractors. Two are worth your time before you buy anything: "Homebuyers' Guide for Foundation Evaluation" and "Foundation Maintenance and Inspection Guide for Residential and Other Low-Rise Buildings." A third, "Distress Phenomena Often Mistakenly Attributed to Foundation Movement," is the one that tells you which cracks are not your foundation.
Titles verified 2026-08-30 on the Foundation Performance Association publications list — SC-06, SC-07 and SC-03 respectively.
The same stack of paper that scares a buyer when it's missing will settle them down when it's organized. Foundation history handled well is a negotiation you've already won.