A hard case is where making everyone happy is going to be difficult.
A vacant house that has been underpinned, but shows severe & extensive distress
The standard explanation, or at least the one I most often hear, is that after the foundation was underpinned, the owner never got around to repair the distress. I used to be suspicious of this explanation, but I have come to the conclusion that, in many cases, the homeowner is telling the truth.
I have found that there are many homeowners that signed the repair contractor because he or she believed one of two things. One: the house could not be sold at the desired price and two: the warranty to be issued by the repair company would make it possible to get the desired price.
Houses that have been repeatedly underpinned
I have seen homes that have been underpinned five or more times. There are a number of reasons why underpinning might not work as well as we would like. The most common reason is that the underlying reason for poor performance has never been identified much less corrected. Underpinning without correcting poor drainage, tree issues and failing to install an automatic foundation watering system is a waste of money, but this is a common problem.
It is also possible that the foundation is simply too flexible for the soil it sits in. This is a risk any buyer has to bear.
Houses that have flooded may have lost some ground support, especially if the supporting soil has sand in it. All slab-on-ground foundations have some leveling sand even if the rest of the supporting soil is pure clay. It is likely that any foundation distortion is likely to be a settlement between the stiffening beams, especially at the foundation corners.
It rarely severe enough to require foundation repair, but it does happen.
I am occasionally asked if the best house to buy is a new home with a 10-year third-party major structural defect warranty. My take is simple: if you read the warranty you will see that the warranty covers what is bound to be a rare event. It does not provide any protection against the common issues that come up. It may be better than nothing, but it is pretty close to useless in my opinion.
Houses excessively out of level
If a house shows only minor cosmetic distress and if the elevation measurements are consistent with only normal deflection and tilt, the out-of-levelness should be no more than a minor nuisance. There is no engineering standard, building code, or guideline that uses levelness as a repair indicator. None. NONE as in zero.
What is used is deflection and tilt. Given a choice between stability and levelness, I’d take stability every day of the week.
Buyers with unrealistic expectations
Unrealistic expectations come in two varieties: one – expecting that a house on a slab foundation will never suffer any distress due to foundation distortion and two – the view that even minor distress is a sure sign of foundation failure.
Here is a realistic description of what is reasonable. Sometime after the house is constructed, starting from day one until the house is demolished it will exhibit some degree of drywall cracking, brick veneer cracking, sloping floors, door frame distortion, masonry fireplace chimney rotation, etc.
These are largely cosmetic and can easily be repaired without repairing the foundation. Some people will respond that after repairing, say, the cracked brick veneer it could crack again and that is certainly true. I always suggest that they read a typical repair warranty. They will find that the foundation repair warranty does not cover what they are most concerned about: drywall cracking, brick veneer cracking, sloping floors, door frame distortion, masonry fireplace chimney rotation, etc.
Buyers with friends or relatives
Let me just tell a story.
I was once asked by a single mother to assess the performance of a foundation on a house she had made an offer on. The house seemed perfect for her and her child. It was close to the school and her church. It was priced right. The only reason she was concerned about the foundation was that her boyfriend has told her horror stories about Houston foundations.
There were no cracks in the brick veneer or the drywall. There were no door issues. The elevation measurements were consistent with the lack of distress in the house. Everything indicated that the foundation was performing better than average.
After I submitted the report, her boyfriend called and demanded that I meet with him at the house so he could show me what the house needed foundation repair. I normally would not do that; he was not my client. However, the listing agent referred me to her clients for making foundation performance assessments for several houses per year.
Besides, I was curious.
We met at the house. The first thing he showed me was the driveway. The section adjacent to the street was new. I explained that the driveway was not part of the foundation. One had no effect on the other. He insisted that the last driveway section was replaced only because it was in bad shape and that proved that the supporting soil was bad.
Next, he told me to follow him to the left side of the house. I followed. Then with both of us staring at the left side brick veneer wall, he said: see, the owner is hiding the cracks. I looked at the wall but there were no cracks and no sign of any repair. I pointed that out.
His response was that foundation repair was common in this area and that the lack of cracks showed that the owner was covering everything up.
I told him I had seen and heard enough and no changes would be made in the report.
About a week later I received a call for another single mother. She told me that the other buyer had backed out. She asked if I had any concerns about the foundation and I told her it was just an older production home and there was no reason to be concerned about the foundation.
Beware of friends, uncles, parents, etc who think they know somethings about foundations. They may mean well but they do not neccessarily do good.