Determining Inaccessible Foundations


Curiosity questions here… I was speaking to an inspector who had done a condo inspection. He indicated on his client’s report of an inaccessible crawl space. He said it couldn’t be inspected because there were no access points to enter. I was intrigued to how he was able to make the determination of a crawl space foundation when he can’t even see it or access it. So, assuming total concealment and inaccessibility, how would an inspector determine the foundation type (i.e. crawl space vs. slab)? Would there ever be an instance where the inspector would have to report the foundation as “unknown”?


I can most likely determine if the foundation is a cement slab or supported crawl from the exterior of the structure. Again, usually.
My question is why was it mentioned.
When I perform a condo inspection it is limited to only the interior of the unit itself.

There are a number of ways to determine the type of foundation without “accessing” it.

You should be able to distinguish a solid slab from a conventional wooden subfloor by walking on it.

Head-butting it works even better

Yes, Randy, most can do that, I would guess.

Thanks all. Here is the backstory… My first inspector, who had inspected my condo, stated on the inspection report that I have a slab foundation. Months later after closing, I am experiencing airflow issues with my heat registers. I could put a tissue in front of these registers and the tissue would not move. This was not caught during inspection. I reached out to the homeowner’s association asking for the layout of the duct work, and I was told the ductwork is accessible by going through the crawl space.

Of course, I reach out to the inspector about the missed crawl space. His defense argument for missing the crawlspace was that the access to the crawl space was concealed and blocked by personal belongings. Eventually, I hired another inspector, described in my original post quoted. The second inspector asked how my first inspector missed the crawl space. I tell him that the first inspector reported I had a slab. The second inspector then tells me that he inspected a similar condo to mine in the same community and even with no access points into the crawl space, he still knew that it was a crawl space foundation.

The second inspector reports issues relating to moisture and what appears to be mold. I then reach out to several waterproofing companies and they all confirmed a lot of work in my crawl space is needed. The estimates vary from $6,500 to $19,000 depending on the scope of work (mold remediation, insulation removal and replacement, vapor barrier install, perimeter drains, sump pump)

As stated before, the first inspector’s reasoning for missing the crawl space was because the access was concealed. I just feel this does not excuse him from reporting the foundation type incorrectly (slab) in the first place. Thoughts?

He cannot make up his mind?
He puts in writing it’s a slab & then tells you on the phone after the fact there was no access.
This does NOT add up…

My apologies. There is a lot to this situation, and I didn’t want to write a novel. After seeing Marc’s post, I realized I may have left an important piece. When I initially contacted the first inspector about the missed crawl space, I requested he come back out to inspect the crawl space. He agreed to come back out. So, the entire length of my crawl space is about 38 feet; the access to the crawl is located around 26 feet. I asked him if he could inspect the entire length up to the foundation wall. I can’t remember the reason why, but he refused. Only speculation. But my guess was that he wanted to avoid a situation where he had to report some bad news. Or he didn’t feel comfortable getting dirty from crawling on the dirt floor. On that day, I remember he had on a casual outfit and didn’t bring any protective gear (i.e. coverall or respirator). In hindsight, I regret not pressuring him to travel the entire length of the crawl space. He goes in and did his inspection by staying in a 3 to 4 feet radius from a squatting position. After several minutes, he comes back up and tells me there are no problems. I felt relieved that no fixes were needed. Obviously, as I discover down the road, that was far from the truth. Months later, I am discussing plans with my HVAC contractor on fixing the duct work. I reach out to the HOA requesting approval as well as explaining the work that is being done. From this conversation, I learn of a second access to the crawlspace that is available inside a closet near the front of the house. I find the access that was hidden underneath a rug and I figured it wouldn’t hurt to take a peak. I knew immediately that there were problems, after seeing standing water along the foundation wall and sagging insulation. As stated earlier, since the first inspector stayed in a 3 to 4 feet radius, there was about 20 feet leading up to the foundation wall that was not inspected. This was when I decided to hire a second inspector to inspect the entire length of the crawl space. This was also when I contacted the first inspector again after learning of the costly fixes that are needed.

Sounds like you have a justified case against a shoddy inspection, for both the missed heating ducts and the crawlspace, with the latter obviously the much bigger issue. This would be a no-brainer if this happened to me & I surely wouldn’t be paying for anything.

Curious, how did you hear about or how were you referred to each inspector?

Crawlspace vents are also good indication of a raised foundation. Sounds like first inspector neglected due diligence in locating access and evaluating the crawlspace.