Structural Engineer / Foundation question

VortecJeep

VortecJeep

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Aug 24, 2005
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Concord, NC
We have a house under contract. This was revealed during the home inspection.
The home is multi-levels and was built in 1984. Part of it has a basement, part of it has a crawl space. This picture is of the crawl space. The wall you see on the right separates the crawl space from the basement. This is what the inspection report says: "The crawl space has a dug out area with steep dirt which has begun to fall. Some base of foundations are exposed due to erosion. The area of trenching is not safe for access without a retaining wall to protect from soils detached."

There are no signs of the foundation settling, no cracks in walls, no doors or windows sticking, no uneven floors.

We are still in the due diligence period. I'm thinking I will call either a structural engineer or foundation repair company to inspect and give me an estimate of repair. Anyone dealt with anything like this?
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If it's in the crawlspace, what is causing the erosion? That would be my main concern.

As far as the dirt under the vapor barrier, looks harmless. To me it looks like what the original contractor did was slope the excavation for construction of the basement and the wall then just left it.

I'd guess that you have type B soil, which means a 1:1 slope is permissible for persnonnel in the trench. I'd say you are close to 1:1. I don't see an issue with it unless it's really deep. It's only 7-8 blocks high so it's not that deep.

To me it sounds like the inspector was trying to find an excuse to not crawl up in there and do his job.

If I were buying the house I'd find out where the erosion is coming from before I'd worry about the soils. I can't remember but there may be some language in the code book about the grade in the crawlspace being uniform. @shawn is the code guru
 
To me, it just looks like that area was never backfilled after inital construction.

Could be good for you actually as that wall hasn't been sealed.

I would apply sealer to that wall, let dry, and then back fill with adjacent soil.

The efflorescence (white fuzz) on the blocks near the soil level indicate a good amount of moisture in the soil, which leads me to suggest applying a thick sealant to the wall prior to backfilling.

If it is erosion, look for soil disturbance due to direct water intrusion.

This will look like sand at the beach that water runs through and similar to a sand creek bed type surface. If it hasn't been disturbed with significant water, it will be very simple to find the water entry and exit points.

If it is getting significant water entry near the corner, adding a sump and pump in that area would be ideal. I would recommend using a 30 gal trash can surrounded by rock.

This is so a pump of adequate size is fully submerged when operating, and won't flood surrounding areas before it raises the float enough to cut the pump on.

As well you could slope a short piece of 4" corrugated pipe along that wall to the sump if desired.

All of that to be done prior to leveling the soil as much as possible.

The sump would be placed to match the desired final grade.
 
In the kind of work I do, the geotech engineer would specify what the maximum slope in the crawl space would be. It's not uncommon for them to require geotextile reinforcement above 2.5 or 3:1.

The photo is a bit blurry, but I'd want to check out what's going on in the foundation step that can be seen at the back of the trench. It looks like there's a lower spread footing on the right side of the image, then they step up vertically approx. 56" and continue the spread footing on the left, but it's not clear that there's anything connecting the two footings, and the soil supporting that spread footing is right at the edge of the cut, so could fail over time. That's probably what the inspector is suggesting, but again, it's hard to tell for sure based on the photo.

The inspector takes no liability. His job is to point out anything that looks out of the ordinary, and put the responsibility on someone else to evaluate and determine whether or not it's a problem.

That said, based on the information provided, we don't know what's on the back side of either of those walls. Even though it may have been "fine" for 30 years, if the exterior of the building is on the opposite side of the far wall, you could imagine a scenario where (as just one example) a clogged downspout and a 3-day tropical storm could saturate the soil on the far side of the wall, causing water to run through into the crawl space, displacing soil under the footing and causing the footing to fail. The photo appears to show efflorescence on the interior side of the wall, so there's some water movement there already. I'd recommend getting a structural engineer and waterproofing contractor to take a look at it. They'll probably recommend cutting down the slope or adding some dirt back in that corner to support the foundations, but they'll probably need to waterproof the existing walls first (at least on the right side, where it's adjacent to occupied space).
 
Thanks guys, that gives me a little more info to go on. I plan to have a structural engineer come out and look at it, hopefully this week.

when we first looked at the house, I saw that trench and said " that's where the dead bodies go." My 9-year-old came running wanting to see the bodies!
 
Call my buddy Fred at Falcone Crawl space and Structural repair. Worked for him for a couple of years during the recession. They will come out and look at it and give you advice/quote. They do good work and know what they are doing, at least when I was there. At the very least, it will give you bargaining material when dd is up.

Tell him Tim Christian referred you.
 
If there's much of a moisture problem, I'd want it fixed. The more moisture, the more mold & musty smell you will always have. I have a couple of effervescent areas in my full basement, but they stay dry & have not caused any smell. Improved drainage & gutters have helped a Lot!
 
Im no engineer, but Ive seen alot of split crawlspace/basements like that. Almost all of them are sloped down to the wall. Maybe not as severe as yours, but like said it seems they dig it out to build the wall and just leave it. the efflorescence and any water mitigation would worry me. Check where the downspouts flow. I was called to look at a job to fill a crack in a block split basement. The wall had bowed in approx. 6 inches and was about to fall.... all because the downspouts were draining against the house... needless to say I did not repair that crack lol
 
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Structural Engineer will be there Wednesday.

As for moisture content, it doesn't say in the house inspection report, but in the termite inspection report (same inspector) it lists the crawl space moisture content at 16%.
 
VortecJeep said:
Structural Engineer will be there Wednesday.

As for moisture content, it doesn't say in the house inspection report, but in the termite inspection report (same inspector) it lists the crawl space moisture content at 16%.
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That's good for wood MC this time of the year. That's not high enough to grow the type of mold that eats the wood itself. That MC will only support the type of mold that eats the sap on the wood surface.

* as long as the entire house is 16% and no areas above 19.
 
Thought I'd give an update.
Structural Engineer came out this week. Inspected inside the crawl space and around the exterior of the home. The slope of the dirt is better than 1:1, but he likes to see 2:1, so it's not critical to fill in the trench, but the 4.0 thing to do would be to fill in at least part of it.
There were 2 locations that he recommends having the foundation secured. He gave some details in his report on where and what he recommends. He did say it is not critical yet, so we do have some time, but I don't want to wait too long.

He said the first thing he would do is some grading work in the backyard. The yard does have a slight slope away from the house for probably 10 feet, but then the rest of the backyard slopes towards the house at a steeper slope. He believes that is allowing water to seep into the crawl space and cause the erosion. So that is something we will ask the sellers to address as part of our due diligence. I doubt they agree to fix it, but I have to ask.
 
As long as your comfortable correcting the problems on your own, or even hiring the repairs, it's generally easier to ask for the cost to be deducted from the sale price. When I bought, my house needed new roof shingles. Seller didn't want to do that, but we ended up splitting the standard estimate. Then I paid for up-grades & hired who I wanted to. I got a reduced price on the sale, & handled the repairs when & how I wanted to. Works out for both party's!
 
rodney eppes said:
As long as your comfortable correcting the problems on your own, or even hiring the repairs, it's generally easier to ask for the cost to be deducted from the sale price. When I bought, my house needed new roof shingles. Seller didn't want to do that, but we ended up splitting the standard estimate. Then I paid for up-grades & hired who I wanted to. I got a reduced price on the sale, & handled the repairs when & how I wanted to. Works out for both party's!
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That's what I'm hoping for, I'd rather get some knocked off the price so I can control who does what.
 
As I said before, call Fred at Falcone Crawl Space & structural repair. They will do a free quote, and you can use it as a bargaining tool. Had two friends buying houses do it already, and got the fee knocked off the buying price. Sounds like you need a french drain along the back of the foundation. They are very knowledgeable, and will give you a price to fix the problem, especially since you now have an engineers report.
 
A nice swale would probably do just as well as a french drain in his situation. Since the engineer is just calling for grading, it doesnt seem as if there is a high amount of flow towards the house. The land around my house slopes E/W and my house sits N/S. I created a small flower bed on one side that basically shed the water around the house. An area that once stayed damp, now has to be watered.

I cant say it enough, but look into having the crawlspace portion encapsulated. It will make the other half more comfortable and usable. Ill never own another crawlspace home w/o encapsulation.....
 
RobMcBee said:
A nice swale would probably do just as well as a french drain in his situation. Since the engineer is just calling for grading, it doesnt seem as if there is a high amount of flow towards the house. The land around my house slopes E/W and my house sits N/S. I created a small flower bed on one side that basically shed the water around the house. An area that once stayed damp, now has to be watered.

I cant say it enough, but look into having the crawlspace portion encapsulated. It will make the other half more comfortable and usable. Ill never own another crawlspace home w/o encapsulation.....
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It's likely not a high amount of flow towards the house since it was built in 1984 and the issue isn't any worse than what it is.
Can you post a pic of how you did the flower bed to shed water? Wondering if I would need to place it on the slope coming toward the house or up next to the house.
 
The water coming down the hill hits a small swale in front of the bricks and sheds it towards the front yard. Before I did this it sloped directly to the house. The area would stay damp. Now I have to water the hollys and my Jap Maple never goes thirsty.

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How much did the foundation inspection run you? I'm starting to get some sticking doors and I think it's foundation related.

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rodney eppes said:
Not familiar with contracts & engineers, but that seems like a High "Opinion". Ouch!:eek:
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We're $110 an hour, and we're the cheapest (that I know of) in the state (Consultant mechanical engineer) but no minimum, and we don't charge to talk on the phone or initial consult. Only charge once we're "on the job". if I could charge like an attorney and bill folks for phone calls, or any time I'm even THINKING about a job....I might actually MAKE a little money at this engineering thing

Electrical engineers are typically $135 to $150 (here in the triad, typically higher in Charlotte/Raleigh)

Keep in mine, we have $10,000 or more a year in insurance, software is between $2500-$6000 per computer per year (7 stations) and computers tend to last between 5-7 years before you're forced to upgrade to keep up with software ($5000-$8000 per computer)

Then, there's the knowledge......


The Graybeard engineer retired and a few weeks later the Big Machine broke down, which was essential to the company’s revenue. The Manager couldn’t get the machine to work again so the company called in Graybeard as an independent consultant.

Graybeard agrees. He walks into the factory, takes a look at the Big Machine, grabs a sledge hammer, and whacks the machine once whereupon the machine starts right up. Graybeard leaves and the company is making money again.

The next day Manager receives a bill from Graybeard for $5,000. Manager is furious at the price and refuses to pay. Graybeard assures him that it’s a fair price. Manager retorts that if it’s a fair price Graybeard won’t mind itemizing the bill. Graybeard agrees that this is a fair request and complies.

The new, itemized bill reads….

Hammer: $5

Knowing where to hit the machine with hammer: $4995
​
If #57 stone only costs XXX per ton, why does it cost me XXXX to have it delivered and precisely dumped down my driveway?
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