No two issues are more likely to hinder the sale of Texas residences than apparent foundation damage or leaks on underslab sanitary drain piping. At the same time, no two issues are more misunderstood by the typical homeowner, home buyer, home seller, inspector, engineer, plumber, and real estate professional. It is both disheartening and a source of pride that my opinions are contrary to the majority opinion of the above groups.

In the mid 1990’s, underslab plumbing leaks became the number one blamed cause of differential foundation movement in the State of Texas virtually overnight. How was this hidden threat to the performance of residential foundations discovered? I’ll give you a hint; it wasn’t by anyone with knowledge of soil mechanics, structural engineering, foundation repair or even plumbing. It was a jury of our peers.

The insurance policy that most Texans purchased at that time to cover risks to their primary residences contained wording that can be paraphrased as follows: foundation damage; cracking, settlement, bulging and/or heaving is not covered. And on another page of the same policy, wording could be found that can be paraphrased as follows: damage from the accidental discharge of water from a plumbing system is covered. In a south Texas courtroom, a jury concluded that if foundation damage was caused by a plumbing leak, then foundation repair should be covered by the homeowners’ insurance policy. Within months, many foundation repair contractors started plumbing divisions and most began blaming differential foundation movement on plumbing leaks, almost to the exception of all other previously blamed causes. Insurance companies, which historically could deny foundation damage claims simply by pointing to the wording in the policy, suddenly had to run extensive tests on the underslab plumbing, and if it leaked, hire engineers to inspect the property and render opinions as to the contribution of the leak to the condition of the foundation. Most homeowners received insurance settlements to help with accessing and covering-up the leak, if not the actual repair, and some received help for foundation repair. And then there was mold!

In the late 1990’s, a similar courtroom interpretation of the same homeowners’ insurance policy instigated another primarily Texas phenomenon I call the “mold controversy.” Articles with titles such as Mold is Gold began appearing in legal journals comparing the mold threat to the hazards of asbestos. However, after a few years the gold tarnished as insurance carriers threatened to limit writing policies in Texas due to heavy financial losses resulting from mold claims. The state allowed the carriers to change the wording on the policy to limit mold losses, and many carriers either eliminated the foundation/plumbing relationship with the same edit, or made such coverage available as an added endorsement. Mold gold quickly turned to lead, but blaming foundation damage on underslab plumbing leaks remains semi-precious to this day…. and dangerously misunderstood.

The worst performing foundations I have inspected over the past twenty-two years were in their poor condition because of prior partial foundation repairs. Only two out of the worst hundred foundations were caused by other reasons; one straddled the Long Point Fault and one was built on top of a prior excavation approximately fifteen feet deep which was not back-filled properly. Put another way, the leading cause of the vast majority of serious residential foundation problems in Texas is prior foundation repair. In 1996 the Wall Street Journal published an article quoting an engineer as saying, “seventy percent of the money Texans spend on foundation repair is wasted.” In the same article a professor of civil engineering at Texas Tech University said, “Some so-called repairs can make the damage worse.”

In the mid 1990’s a huge market developed overnight after a courtroom interpretation created the demand from Texas homeowners’ insurance carriers to test underslab residential plumbing systems and inspect foundations. The demand to test underslab piping was filled by plumbers who began running cameras and inflating testballs in drains to check for leaks. The demand to inspect foundations for insurance companies was filled by existing forensic engineering firms. The demand to inspect foundations on behalf of homeowners, often after an engineer working for their insurance company
concluded that the plumbing leaks did not contribute to the differential foundation movement, was filled by the engineers already providing real estate inspection services in conjunction with the sale of residential property. It became popular for these engineers working for homeowners to opine that underslab plumbing leaks cause settlement and mimic what was being said by representatives of the foundation repair industry to explain why foundations piered around the perimeter begin sinking in the center. There are more than a few geotechnical hurdles to leap when theorizing about the settlement of slab foundations constructed on expansive soils being caused by plumbing leaks. In fact, these theories have been disproven in research papers by some of the leading geotechnical engineers in the state. Real estate inspection reports that claim underslab sanitary leaks cause settlement in the presence of expansive soils are wrong, and such opinions reflect a lack of understanding of basic soil mechanics. Such leaks, if they have any effect at all would cause heave and not settlement.

If you choose to refer an engineer instead of a real estate inspector to perform a pre-purchase inspection of a home, then the engineer you refer should be licensed by the State of Texas and have the initials P.E. after his or her name. It is up to the individual engineer to practice within their area of expertise. Most young engineering graduates that plan on ever being licensed to practice engineering take the EIT (Engineer-in-Training) or Fundamentals exam as a senior in college because it is very broad and difficult to pass after being out of school for any length of time. After passing the EIT exam, receiving an engineering degree from an accredited program, and working for the required time in the profession under licensed engineers, the young engineering graduate can apply to take the Professional Engineer Exam in his or her field and become licensed to practice and advertise engineering services to the public. It is very common for young engineers, while working to fulfill the time requirements toward becoming registered, to put the initials E.I.T. after their name on their business cards or on their professional correspondence if they have passed the exam. In the field of structural engineering, it is very common to see the initials MSCE or PhD as well as EIT, because most structural design positions in the architectural field require at least a master’s degree. We recommend to our clients that they confirm the degrees obtained, the registration status with the State of Texas, and the experience level of any home inspector advertising as an engineer. The following two recent case studies involve home inspectors advertising to the public as being engineers.

We received a request to test the plumbing beneath a house in the Briargrove section of Houston as part of pre-purchase inspections. The house had experienced some differential foundation movement and the buyer wanted to make sure that the underslab plumbing did not leak. I visited with the buyer several days before our inspection and informed him that many of the redeveloped properties in the subdivision were constructed on original piers, and suggested that the likelihood of any sheetrock cracking being caused by a plumbing leak was remote. In fact, many slab homes constructed since the 1930’s utilize original drilled piers, yet many home inspectors are ignorant of this fact. Many of the original homes in the Spring Branch and Memorial areas, the West University and Rice areas, the Braes Heights area, and to my knowledge the entire Tanglewood subdivision, were constructed on original drilled piers. Furthermore, many of the redeveloped properties in the most desirable areas of Houston have the second house constructed on the lot founded on original drilled piers, even if the first one was not. It is easy to read the crack pattern in sheetrock walls and determine with near certainty whether or not a house was constructed on piers or has had remedial piers installed. Correction, it is easy for an engineer with a basic knowledge of the mechanics of materials. Without such knowledge, an inspector can always probe the corners.

While probing a corner of the house built in Briargrove to confirm to our client (the buyer) that the house was constructed on builder’s piers, we were asked by the engineer performing the structural inspection what we were doing. When we told him that we were probing for piers he said, “No way will piers be present. This house has cracks in the sheetrock and would not have cracks if it had original piers.” We proceeded to dig up the pier and show him. He asked why there was standing water beneath the gradebeam so we mentioned the void boxes that often accompany original piers. The inspector did not appear to understand the term.

Lessons learned: Properly identifying the foundation system as either a slab-on-grade, slab-on-original piers, or slab-on-remedial-piers (prior foundation repair) should be part of any foundation inspection. A homeowner finding out that their home was constructed on original piers after purchasing it might consider it a pleasant surprise. A homeowner finding out that their home has had prior foundation repair around the perimeter after purchasing it or when the center begins sinking is not a pleasant surprise…….and often easily preventable.

We recently received a request by a homeowner to test the plumbing under a home in the Braeswood area of Houston. The homeowner had been told that the settlement on the interior and the resulting cracking which was occurring in the brick and sheetrock might be the result of underslab leaks on the sanitary drain piping. The homeowner sent me two inspection reports signed by an engineer describing two previous inspections performed by the firm’s employees. The first of these inspections was performed in 2013 as a pre-purchase inspection of the home which had been “flipped” by a seller after performing cosmetic upgrades. The second of these inspections was performed in 2015 after cracks began to appear in the brick and sheetrock. Both inspection reports referred to the house as a slab-ongrade.

In speaking to the homeowner over the phone after reviewing the reports, I suggested that the foundation had likely been piered before as many have in the area. He insisted that it had not because the prior engineering inspection reports did not mention it. I asked him if the driveway was new, and if
the front and back patios were covered in tile by the previous owner as part of the upgrade. He said that the patios were in fact covered in tile, and that the driveway was in fact new. I told him that without patches in the concrete driveways and patios, most home inspectors will not be able to report whether or not a house has been piered. Many inspectors either do not recognize the basic crack pattern indicative of perimeter piering, or do not probe the corners to determine if piers are present. We were in the neighborhood so I offered to stop by the house and probe the corners for the existence of piers. We quickly confirmed that the house had been piered.

Lesson learned: Many older homes have had the driveway replaced, and had tile placed on the porches and patios. This is a very frequent situation with “flipped” residences. The new driveway paving and tiled patios hide evidence of past foundation repair reflected in the form of patches to the existing concrete adjacent to the foundation. If the inspector does not probe the corners, or if the engineer cannot interpret crack patterns correctly, then the existence of remedial piers will be missed.

The worst leaking underslab sanitary piping systems I have inspected over the past twenty-two years have been in their poor condition because of prior foundation repair. Foundation repairs and leveling efforts tend to break the underslab sanitary piping much the same way that roots are broken when
plants are lifted out of the ground. The other factor besides prior foundation repairs making underslab systems at a higher risk of failing a hydrostatic test is the presence of cast-iron. Cast-iron was the pipe material used for underslab sanitary piping until the early nineteen-seventies, at which time the use of cast-iron was replaced by black (ABS) plastic first, and then white (PVC) plastic toward the end of the decade. Cast-iron will deteriorate over time, lasting anywhere from twenty years to one-hundred-andtwenty years, or more. If you believe that the cast-iron from the sixties and prior is on the verge of failing, why test it? Does it matter whether it passes or fails a hydrostatic test, if failure is eminent? Why not tunnel under the foundation and replace it? I can think of one reason…. how about if the tunnel to replace the piping allowed more water under the foundation than ever leaked from the system? Would you still tunnel under the foundation in the name of preventing foundation problems?

Plumbing reports which state It is always better to replace cast-iron before structurally damaging leaks develop should also be viewed with skepticism. If you are a homeowner, a homebuyer, or a realtor, and you have been told that a leak on the sewer pipe can damage your foundation, have you considered whether or not a tunnel dug to replace the sanitary piping is also a hazard to the foundation? After all, the tunnel will almost always be a path for more water to migrate under the foundation during rain events than ever leaked from the sanitary piping whose replacement required the tunneling.

We were recently asked to test the sanitary piping under a foundation by a seller after an inspector for a buyer ran a sewer camera through the three systems and reported that he observed hairline cracks and minor leakage and stated that it is always better to replace cast-iron before structurally damaging leaks occur. No hydrostatic testing was performed, no video was forwarded to the seller showing the hairline cracks, and the buyer demanded that the seller replace the underslab sanitary system in its entirety. We tested the system for the seller and discovered that two of the three systems did not leak, and the third dropped very slowly. We suggested to both the buyer and the seller that the tunnel to repair the one leaking system would allow more water to migrate under the house during rain events than was currently escaping the piping under normal service conditions, and suggested that to tunnel under the foundation and replace the other two systems that were not leaking was not in the best interest of the
foundation. We suggested to both the buyer and the seller that a financial arrangement would likely have to be made considering the cost of repairing the one leaking system, regardless of whether or not it was actually repaired.

Lessons learned: A video inspection is seldom enough to determine whether or not a sanitary system is leaking beneath a residence. Only about half of the cast iron sanitary systems installed beneath residences constructed prior to the early seventies fail a hydrostatic test. Of course, the percentage of
failures increases dramatically on residences which have had prior foundation repair. If you are a realtor routinely suggesting that underslab cast iron sanitary piping which fails a hydrostatic test should be repaired because it can cause foundation damage, then how do you feel about the tunnels to replace the piping? Can these tunnels cause foundation damage? Are the leaks or the tunnels a greater hazard? If you refer consultants who believe that it is always better to replace underslab cast iron before structurally damaging leaks develop, how would you feel about referring doctors who believe it is always better to have a heart transplant before the onset of life-threatening heart disease? Remind me again, which one of us is PLUMB CRAZY?