The New Oxford American Dictionary, 2nd edition defines the word inspect this way:
To look at (someone or something) closely to assess their condition or to discover any shortcoming.
This applies to much of what a TREC home inspector does.
Here is how the same dictionary defines the term:
investigations: to carry out a systematic or formal inquiry to discover and examine the facts of so as to establish the truth.
The Texas Board of Professional Engineers considers a foundation performance evaluation to be an investigation. In a foundation performance evaluation, the truth searched for are several items:
Is there any visible distress or damage consistent with foundation distortion?
Slab-on-ground foundations react to shrinking and swelling soils in predictable ways. Any competent structural Texas Professional Engineer can easily obtain the knowledge to reliably identify the cause of distress or damage to the house.
Is the house livable and safe?
It is rare for a house to not be liveable. On the other hand, most homes have numerous safety hazards. Virtually every breaker box is full of code violations any one of which could result in a fire and death for the occupants. Yet most homeowners do not really care judging by the fact that the defects almost never get corrected.
In any case, when it comes to foundations, no slab-on-ground foundation has ever broken someone’s leg, or caused someone’s house to burn to the ground.
Are there any indications of structural integrity issues?
A structural integrity issue is where a load-bearing element or assembly is in danger of being pulled apart. Severe cracking in the slab concrete can indicate structural integrity can indicate a need to repair the foundation. I once saw a slab-on-ground foundation that had a crack that was well over 1.3-inches difference in elevation between one side to the other side.
Is there evidence of a continuing problem?
If a foundation has been underpinned more than once, I consider that foundation to be a continuing problem. Foundation repair without any information as to why the foundation was underpinned is a suspect situation.
How is the performance as compared to houses the same approximate age, location, and construction?
You can make this type of judgment reliably only with a lot of experience. The main thing to keep in mind it that expansive soils underly virtually all of the Greater Houston Area. Generally speaking, the soils are more expansive south of Buffalo Bayou and I-10. North of I-10 the soil is less expansive. The soil at the surface is frequently sand with some silt mixed in. Six or twelve inches down the soil is mostly clay and it is usually expansive.
There is a soil formation called the Beaumont formation. The clays are very expansive and extend well into the eastern part of Harris County.
Is the foundation a good candidate for foundation repair? If not, why not and if so, why?
There are many slab foundations that are not good candidates for underpinning. I consider any slab foundation built before 1970 to be a poor candidate. Why? Because the first design manual was published in 1970. That design manual was used to design both post-tensioned and conventionally reinforced slab-on-ground foundations.
Is there other remedial work that could be done to improve future performance?
In the large majority of homes that show some degree of distress that consistent with foundation distortion, there are aspects of the property that, if corrected, would enhance the performance of the foundation.
Consider a typical slab-on-ground foundation that is 30-years old in the Westbury area.