What method do you use to inspect a slab on grade foundation? If there are no obvious signs of problems like uneven door frames or tilted floors what else can you do to collect information?
I have a 100’ liquid digital level
More like checking floor vents if embedded and nearby trees.
When I was younger we used an EDM and would shoot all the corners of the building and compare it with a bench mark and a topo. But that is a little outside of the average home inspection
I do a visual inspection of the ext and int of the
home.
I also do NOT use the term ‘cracked slab’
Find a GOOD inspector to shadow and he/she
will give you some good info.
Regards
Call it what it is…monolithic.
Without x ray vision I can’t see nothing but concrete…Huh?
Sorry for being so short Michael.
I did a ride along with a struct’ Engineer and
HE advised me to never use the term ‘cracked foundation’ as
many see that as a failed foundation.
He gets atleast 1 call a month from a realtor because
an Inspector used those words.
He said and showed me the main concern is the active area of the slab, outer
most 10 Feet of slab as it exibits the most
issues from moistire.
“concrete cracks”
LOL
Michael,
Just report what your saw and any restrictions that prevented your from observing the entire slab. Typically you only see the portion exposed between the siding and ground on the outside. Carpet and other flooring prevents a visual inspection on the interior portion. Taking elevations without knowing the elevations at the time of construction is just an exercise in collecting useless data, unless its for documentation for comparison in the future. One exception would be if the slab is completely exposed with visible cracks that occurred after construction. A scaled drawing with elevations and visible cracks together with other supporting data such as drywall or brick veneer cracks may provide enough information to conclude that a low spot was the result of settlement versus poor workmanship when pouring the floor. Keep in mind post tension slabs can settle without creating large cracks. Providing elevation data also puts you in a position to answer the questions; is the elevation difference significant?, is it a structural concern?, should it be repaired? Answering these questions is outside the SOP and answering them incorrectly can cost you $$$. For example you scared the buyer and the seller sues you for working outside the SOP and possibly practicing engineering without a license.
And that’s covered with flooring. So when the customer asks, “hows the foundation?” what can you answer? I suppose without it being out of level or visibly cracked there’s not much to observe.
Travis - thanks for the advice on avoiding the words “cracked foundation.” I’ll add that to my file of buzz words to not say.
Randy - I understand the danger of making definitive statements that exceed the SOP but there must be some cases where advising review by a structural engineer is warranted without exceeding the SOP right? I guess I’m trying to determine when that is without sounding alarms.
Michael,
You can say:
- I saw no visible evidence the foundation was not performing as intended.
or
- I saw visual evidence x, y,& z that may indicate a settlement and/or a structural concern that may need further investigation by a foundation contractor or structural engineer.
It’s the buyer’s job to decide what to do with that information. Don’t let them put that monkey on your back.
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Very good advise folks. Thanks Randy.
Bert
You can only report what you can see. If you feel unevenness when walking the floor, out of square doorways, unusual cracking in the stucco or drywall, then that’s what you report and recommend further evaluation by the appropriate expert. You certainly don’t need to break out the water level.
After reading all the comments above I came up with the following comment for slab on grade foundations:
“Slab on grade foundation inspections are inherently limited, as the slab itself is not readily exposed. Typically, only the portion of the foundation between the siding and ground on the outside is visible. Carpet and other finished flooring prevents a visual inspection of the slab from the interior of the dwelling. Therefore, the inspector will report any visible signs of defects on the limited portion of the slab that is visible from the exterior (If any), and other structural defects that would be consistent with slab foundation related defects on the interior.”
Any objections?
I’m using Spectora software and included this as a “Limitation” for slab on grade foundations.
One would hope you report on it, that’s your job after all.
I think it’s too verbose. “Slab on grade foundation, no visible defects” You don’t have xray vision.
When you see one that’s got a problem, you’ll know it. Typically a corner of the dwelling is on a water path that has undercut it or a sink hole opened up underneath and swallowed the bedroom.
Doors hard to open? Ball rolls across the room on it’s own? Probably not a ghost. Huge gaps in the visible block in the garage? Again, when you see one, you’ll know. You don’t know how things were originally poured, so a level isn’t much use. An out of square doorframe will be a big clue.
A garage slab that’s deflected from one side of crack to another? Flooring all wonky? Siding or stucco looks like someone took a pickaxe to it?
I do a visual and report that the grading slopes away from the house on all planes. If it doesn’t, you need to figure out if water has monkey’d around with anything.
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Oh, there are defects. There are always defects. Inspected is a better term, IMO, and note any limitations.
The concrete slab was inspected though many areas were covered up or not visible, which limited my assessment. (Our SoP covers things that are not visible. I just choose to reinforce this point in the report occasionally).
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Here’s what goes in my reports for slabs with no visible defects.
Slab was not visible due to carpet and/or floor covering - no visible defects were viewed.
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