Although putting your finger in to block a leak might be the solution that comes easily to mind, there are probably better solutions.

This is the second blog in a series of blogs helping engineers and those trying to diagnose soil-foundation interactions. In the last blog, I spoke about the anchoring bias, where someone judges a book by its cover. Here’s the link to that post.

The Availability Heuristic in Foundation Repair

In this blog, I want to explore the availability heuristic in foundation repair, which tempts us to reach quick conclusions based on familiar solutions that come to mind. This often involves first impressions, but not always. Sometimes, it may come to mind later, yet it can still be based on easy, lazy thinking.

Industry Challenges

Foundation repair contractors across the nation typically interpret the solutions they see through the lens of products offered by their single-source suppliers. When those suppliers don’t have a product to address a particular problem, the signs of trouble for that issue are often ignored in favor of more easily recognizable problems with straightforward solutions.

The foundation repair industry, which has been around for 60 to 70 years, has developed effective products for addressing home and foundation settlement. However, there are very few solutions available for expansive soil heave. As a result, this issue often goes unrecognized when examining a house.

It’s easier to perceive differences in elevation as settlement and a need for underpinning. Often, the training received by foundation repair sales representatives almost completely overlooks expansive soil heave, as there is no solution from the single-source supplier. Consequently, there is a significant lack of awareness regarding this phenomenon, including how to recognize and address it.

This reminds me of a great saying by Abraham Maslow: “If your only solution is a hammer, then all your problems start looking like nails.”

Personal Experience

In my previous foundation repair business, we utilized licensed forensic engineers to diagnose problems and recommend solutions. Often, the sales personnel who first assessed the situation did not align with the engineering recommendations. Over time, these sales reps began to learn, but we saw this pattern regularly, especially early on with newer representatives.

I can only imagine what it’s like for those sales representatives who lack engineering support to guide their learning.

In the area where I ran my foundation repair and forensic engineering business, a popular YouTube contractor perfectly embodied the Dunning-Kruger effect. He had no experience or education in soil mechanics. Yet, he insisted that he was the only one capable of solving foundation performance problems—despite never having driven a single pile or conducted even one-floor elevation survey.

Misguided Solutions

This particular expert “with 30 years of experience” had a seemingly simple solution that could “easily and instantaneously determine if the sloping of a slab foundation was due to settlement or heave.” Intrigued, I watched on.

His solution was to drill a small hole in the slab and check for a void directly beneath it. What the heck? His reasoning was that there would be no void if the slab had expansive soil heave! Like many with limited experience in soil mechanics, he assumed that wetted clays must be muddy, not realizing the ability of clay to absorb moisture, be plastic, and remain non-liquid.

This example shows how those lacking geotechnical engineering knowledge and understanding of Atterberg liquid limits and plastic limits can engage in lazy thinking. I wrote a blog many years ago explaining these concepts and used an illustration to show how solid plastic movement of expansive soil upward can, and almost always does, create voids under a slab. See illustration below. 

Training Insights

During my initial training in this industry, the trainer was, of course, our single-source supplier. The representative accompanied me to various properties, and during our travels, he casually remarked, “I’ve never seen a house that doesn’t need piers.” This mindset is not uncommon in the industry.

It is easy to arrive at quick conclusions that fit familiar patterns based on data we are used to, overlooking other signs of stress that could lead us in different directions.

Geographic Considerations

This tendency also applies to more nuanced and less obvious areas of understanding. I have often seen experienced geotechnical experts come to Phoenix, with its unusually dry conditions, and apply reasoning from other geographies. While such reasoning may be valid in their home areas, it can be completely out of sync with the very arid conditions found in Phoenix.

There may be many opportunities to apply the easy solutions we are accustomed to. Instead, let’s examine all the data and weigh it carefully to see how everything stacks up.

Now how do we resist the temptation to ignore data that does not fit with our already conceived ideas? Next up the granddaddy of biases…  the confirmation bias.