Foundation repair in Richardson, Texas

Richardson draws its permit line at a pier count, which is the most concrete threshold published by any city in this set: "Permits are required for foundation repairs consisting of four (4) or more piers" (City of Richardson — Foundation Repair).

Four piers is a low bar in practice

A number that specific invites arithmetic. Industry underpinning practice caps exterior perimeter pier spacing at about 8 feet on centre for a one-story wood or brick house and 6 feet for two-story brick (Foundation Performance Association, FPA-SC-08-1). At 8-foot spacing, four piers cover roughly 24 feet of wall — less than one side of most houses, and typical DFW jobs run 8 to 12 piers (The North Texas Home Guide).

So the ordinary Richardson repair is a permitted repair, and the sub-four exemption covers only very small work. The threshold defines when the city wants engineering on file — which makes a proposal for exactly three piers worth a second look, since it lands one pier short of the paperwork.

What the city asks for above the threshold

The submittal is a report, not just a drawing: an "Outline drawing of structure showing the areas of proposed repair and report of items to be corrected and details of how the repair is to be performed. Report must be signed and sealed by a Texas Licensed Engineer." Two procedural conditions follow: "The building permit must be approved and posted at the property prior to any work commencing," and "All contractors must be registered to perform work in the City of Richardson" (City of Richardson — Foundation Repair).

Registration with the city is not a trade licence: Texas licenses engineers, not foundation repair contractors, which is why the sealed report carries the technical weight.

The city's own guidance also notes that once damage appears "it may be necessary to contact a structural or foundation engineer to inspect your home," and that "A correction may be necessary with the use of piers, or simply a more intense watering program may solve your problem" (same page). No fee amount is published there.

Half Houston Black, a quarter Austin

Roughly 52.1 percent of Richardson's area is Houston Black and about 27.6 percent is Austin. The largest map unit is "Houston Black-Urban land complex, 0 to 4 percent slopes" at about 30.1 percent; "Austin-Urban land complex, 0 to 2 percent slopes" covers another 15.7 percent (USDA Soil Data Access).

Those two series are not variants of one another. Houston Black is a Udic Haplustert whose official description records dry-weather "cracks that are 1.3 to 10 cm (1/2 to 4 in) wide at 30 cm (12 in) depths," measured at plasticity index 32 to 78 with linear extensibility to 17 percent (USDA series description, Houston Black; SSURGO). Austin is a Haplustoll — not a Vertisol — with no shrink-swell behavior stated in its official description, PI 16 to 45 and linear extensibility near 7.5 percent (USDA series description, Austin; SSURGO).

More than a quarter of Richardson therefore sits on ground with well under half the swell capacity of the clay the city is known for. On the Austin side, unexplained slab movement deserves a look at drainage, fill and plumbing before seasonal swell is accepted as the cause.

Richardson also straddles a county line: about 64 percent of its area is in Dallas County and about 36 percent in Collin (Census TIGERweb). One permit process covers both; county property records do not.

A 1960s–70s core with a young multifamily layer

Median year built is 1985, but the distribution is two-humped: 20.8 percent of units date to the 1970s and 16.3 percent to the 1960s, while 18.0 percent were built in the 2010s (ACS 2019–2023, Richardson). By the vintage rule, post-1970 construction is almost all slab, and the 1960s share sits close enough to the 1965 line that pier and beam turns up in the oldest streets. No published figure gives the city's actual split.

Watering days are set by street number

From April 1, "even-numbered addresses may water on Tuesdays and Saturdays and odd-numbered addresses may water on Wednesdays and Sundays," and "Sprinkler system watering is not permitted between 10 a.m.-6 p.m. from April 1-Oct. 31, unless the North Texas Municipal Water District asks for more severe restrictions due to drought conditions." The exception is broad: "Watering via drip irrigation, soaker hose or hand-held hose with a shutoff nozzle may be done any day at any time" (Richardson Today).

Two fixed sprinkler days on Houston Black is a coarse moisture cycle; the unrestricted drip and soaker allowance is what makes steady perimeter moisture legal in between — and, in the city's own words, sometimes an alternative to piers.