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Risks for foundation of a house with crawl space converted to basement

IBoughtIt's picture

Hello, we just bought a house that had crawl space converted into a basement. This was a DIY by the owner who is an engineer and architect and has done several remodels and built other homes for himself. I had 3 inspections (for peace of mind) including a structural engineer. None of the inspections were intrusive (as in opening the walls or removing the carpets). All inspectors were happy with the work done and did not find anything concerning. They commented that if I had not told them that the owner had done this work, they would not have known because everything was done well and up to code (except steps of the staircase which were slightly higher). They mentioned the way the concrete floor for basement had been laid out, there was no danger to the foundation. They also mentioned that the max that could happen is the floor may start settling, but since the work was completed in 2003 it would have already settled if the work was not done right. In future it may settle more, but that can happen with any basement.

I am already beyond the point where I can get my earnest money back but I still wanted to check what the professionals here think. They are really great inspectors well known in the area and I should probably trust them but wanted to check here for peace of mind. Are there any issues that could come out because of the way the work was done other than issues that can happen with any house.


There are possible issues (post #215037, reply #1 of 7)

There are possible issues with any house.

"Converted crawlspace" is a red flag, but if the guy knew what he was doing and it passed multiple inspections (and you personally are not sufficiently knowledgeable to evaluate it further) then you can probably assume it's at least "OK".

You should perhaps give the entire site one more look-over, considering water flow patterns in the event of a heavy rain, and whether there might be standing water anywhere, or erosion of the foundation.  This is something you should be able to do yourself, envisioning "in your mind's eye" how water would flow (and stand).

Of all the preposterous assumptions of humanity over humanity, nothing exceeds most of the criticisms made on the habits of the poor by the well-housed, well-warmed, and well-fed.  --Herman Melville

The inspections were only what can be seen (post #215037, reply #2 of 7)

The work is not permitted. All the inspectors had a caveat saying "from what they can see". The did not say anything about footings but they did not see any cracks or such. The report says:


The basement is configured slab on grade. We noted no signs of distress in the foundation wall.

As we understand, the rear basement daylight door was retrofitted. This likely included cutting out of portions of the foundation wall. This scope of work does not compromise the foundationsystem. We noted only hairline shrinkage cracking from the exterior. None of this cracking denotes structural instability.
There is a small crawlspace towards the front of the building which is basically configured with a rat slab or a concrete slab on grade. Again, no distress was noted in this portion of the structure.Small portions of the framing were visible from this crawlspace. The craftsmanship and installation appears good.

I am concerned that they have not mentioned anything about footing. Maybe they saw something like the foundation wall from outside an felt its OK

In most parts of the country (post #215037, reply #3 of 7)

In most parts of the country the foundation around a crawl space would only go down 3-5 feet -- to below frost level.  To create a "basement" one would need to go down 6-8 feet.  The question is how that was accomplished without jacking up the house and building a new foundation under it (something that is actually done with some frequency).

I had assumed that you were implying that the people who inspected the house knew (or at least strongly suspected) what technique was used to overcome this hurdle.  Without such information you're flying blind.

I would also wonder why an architect did not get his work permitted, if permits are generally required in your area.  Yes, there's often some sort of homeowner exemption, but generally not for major structural work.

Of all the preposterous assumptions of humanity over humanity, nothing exceeds most of the criticisms made on the habits of the poor by the well-housed, well-warmed, and well-fed.  --Herman Melville

I did not ask the specific question (post #215037, reply #4 of 7)

Dan, thank you for your response. I did not ask your specifiic question to the inspectors. However this crawlspace seems to be above grade because the basement door opens up to the yard. See picture below for the basement.

maybe this answers your question about this was done without jacking up the house. The seller did mention that this side of the crawl space had high ceilings.

I spoke to both the inspectors again. One is a structural engineer and he believes that there was no need to add additional footing because from what he sees he did not dig deep and the crawl space was high ceiling already. He also believes that the work he could see, for example the seller added a tiny shed behind was well done with piers etc. 

He believes that adding the slab really did not increase the weight on the footings, maybe a tiny bit.

I questioned him whether he could make this decision based on not seeing under the concrete and he said with experience he has seen enough to understand what work has been done.

I know its from 2003 because the seller mentioned in email and we also checked the doors and windows that were fitted in the basement framing were from or atleast manufactured in 2004.

It's unclear whether this was (post #215037, reply #5 of 7)

It's unclear whether this was simply an unfinished walk-out basement (built on a fairly steep slope) or an actual crawl.  If it was a crawl then typically the walls farther up the hill would not have gone down to the same level as the bottom section.  This means that when the basement was dug the footings would have been undermined.  That is the concern.

Of all the preposterous assumptions of humanity over humanity, nothing exceeds most of the criticisms made on the habits of the poor by the well-housed, well-warmed, and well-fed.  --Herman Melville

This was a crawl space and (post #215037, reply #6 of 7)

This was a crawl space and not basement. In the front of the house there is still a little crawl space. Its only at the back of the house that the crawl space has been converted.

It seems like you've put the (post #215037, reply #7 of 7)

It seems like you've put the cart before the horse. You should never have bought this house. All your inspections have told you nothing that matters to the condition of the house or what hidden work was done. The fact that there were no permits issued should be all the warning you needed. In Florida the lack of a permit does not preclude you, the new owner, for responsibilty for the work. If it's the same where you live the building department could force you to return the space to its original condition and make you get a permit to do that! Also in Florida if a seller or agent does not disclose issues like yours you can sue for your money and attorney fees back. I'd confront the agent and demand  your money back. Failing that run  to a good real estate lawyer.

Florida Licensed Building Contractor, 45 years experience in commercial remodeling, new homes, home remodeling and repairs and all types building maintenance.