Short answer: a lot of North Texas sits on expansive clay that shrinks when dry and swells when wet.[1][2] That movement can crack decks, coping and sometimes pool shells. Whether a crack is the builder's problem depends on your written warranty, what kind of crack it is, and Texas Property Code chapter 27, which excludes normal shrinkage cracking within building-standard tolerances.[4]
What the soil does
- The Houston Black series covers about 1.5 million acres of the Blackland Prairie, from north of Dallas south to San Antonio. The Texas Water Development Board calls it a classic Vertisol that shrinks and swells markedly with moisture, and says its very high shrink-swell potential commonly limits building site development in metro areas.[2]
- USDA's official description: 40 to 60 percent clay; when dry, cracks 0.5 to 4 inches wide extend a foot or more deep and stay open 90 to 150 cumulative days in most years.[1]
- Not every DFW lot is Houston Black. Look yours up in the free USDA Web Soil Survey (draw your lot, then open the soil properties report for shrink-swell).[3]
Cosmetic vs. structural: what to note
| What you see | Often | What to do |
|---|---|---|
| Hairline surface cracks in plaster that don't grow | Usually cosmetic (surface shrinkage) | Photograph with a ruler and date; recheck monthly |
| Crack between coping and deck, or deck slabs lifting | Deck/soil movement; the expansion joint may have failed | Note the warranty for decking (often separate from the shell) |
| Crack through the shell that widens, or water loss beyond evaporation | Possible structural issue | Document water loss, call the builder in writing, get an independent inspection |
| Pool no longer level (water line uneven around the tile) | Possible shell movement | Measure the water line at several points; send a written warranty claim |
These are common patterns, not a diagnosis. An engineer or independent inspector should judge your pool.
The warranty and chapter 27
- Chapter 27 says a contractor isn't liable for damage from someone else's failure to maintain the residence, normal wear and tear, or normal shrinkage cracking within building-standard tolerances.[4] Keep drainage and watering records: they help show maintenance.
- For a defect claim, chapter 27 requires written notice by certified mail before suing, and lets the builder inspect and make an offer. See warranty claims for the timeline.[4]
- Owners do describe ground shift showing up after a warranty runs out (for example, an X post we cite as the poster's own account).[5] Check the warranty length for the shell versus the deck and equipment.
Before you sign: questions for a builder
- Will you get a soil or geotechnical report for my lot? Can I have a copy?
- How are the shell, steel and deck designed for expansive clay?
- Where will roof, yard and deck drainage go?
- What does the structural warranty say about soil movement, and is it transferable?
- Put the answers in the contract. See how to vet a builder.
FAQ
Why do so many DFW pools crack?
Much of the Dallas area sits on Blackland Prairie clay. The Houston Black series, the Texas state soil, is described by the Texas Water Development Board as highly expansive clay that shrinks and swells markedly with moisture, and its very high shrink-swell potential commonly limits building site development. The USDA series description says that when dry it cracks 0.5 to 4 inches wide, at least a foot deep, for 90 to 150 days in most years. That movement can stress decks, coping and pool shells.
How do I know what soil is under my yard?
Use the free USDA NRCS Web Soil Survey: draw your lot on the map and open the soil report, which shows the mapped soil and its shrink-swell rating. It is a map-level estimate, not a site test; a geotechnical report for your lot is more specific.
Is a crack in my pool covered by the builder's warranty?
Read the written warranty first. Texas Property Code chapter 27 says a contractor isn't liable for normal shrinkage cracking within building-standard tolerances, normal wear and tear, or damage from someone else's failure to maintain the property. A structural crack that leaks or keeps growing is a different question from a hairline cosmetic crack; get it documented and ask a Texas attorney if the builder refuses a claim.
Should I ask about soil before I sign with a pool builder?
Yes. Ask whether the builder will get a soil or geotechnical report, how the shell and deck are designed for expansive clay, how drainage will be handled, and what the structural warranty says about soil movement. Get the answers in the contract.
Related: warranty claims · final inspection check · builder directory. Checked November 4, 2026. Something wrong? Tell us.
Sources
- USDA NRCS Official Series Description: Houston Black series
- Texas Water Development Board: Houston Black, Texas State Soil (PDF)
- USDA NRCS Web Soil Survey (look up the soil at your address)
- Texas Property Code ch. 27, Residential Construction Liability Act (RCLA) (official text)
- X, @JettBlast00 (Aug 27, 2026): ground shift after the warranty expires
- Texas Attorney General: File a Consumer Complaint
- State Bar of Texas: Lawyer Referral & Information Service