Mike writes: I purchased a lot that was owned by the city I live in. Years ago the city used the lot as a dump for tree stumps, chunks of concrete, brick, and cut logs. The builder discovered the fill when excavating for the foundation. Since he could not build on top of this, he had to dig much deeper and use much more material, which ended up costing me more than $10,000 out of pocket. The city did not disclose that the land had been filled with trash when selling the lot. The lot is in a development with about 12 other houses in it. I believe that junk cleared from the other lots were dumped into mine, then graded and planted with grass. Any advice I can get would be great — is there legal action I can take? Or am I going to have to bite the bullet?
Steve Bliss of BuildingAdvisor.com responds: A filled site can usually be built on if the fill material is suitable to carry the required load, was properly compacted when filled, and does not contain any toxic materials or organic material such as wood (which will rot and leave voids). Unfortunately, this is rarely the case with filled sites which can hide a lot of sins and, like yours, be planted over to look just fine to the casual observer. A soil or geotechnical engineer would need to take test borings at number of locations to establish the suitability of such a site.
Clearly the town should have disclosed the condition of the soil when they sold you the land, and they were probably obligated to do so under modern disclosure laws in most states – that is, if they were aware of the problem. In the bad old days, “Let the buyer beware” was pretty much the rule in real estate transactions. The trend has shifted toward making the seller of real estate more responsible to inform the buyer of known defects. Even with such laws on the books, however, it may be difficult to prove that the seller knew of a defect. Other issues to consider are the cost of bringing a lawsuit – typically well in excess of $10,000, and the fact that the seller is a municipality. Can you sue a city in small claims court? Again, this varies by state as well as the maximum amount of a claim in small claims court.
To determine your specific rights in your state, and the best strategy for resolving your dispute, you would need to talk to a lawyer — many will speak to briefly for free and tell you whether you have a snowball’s chance in heck. Laws on disclosure of defects vary from state to state, and “defects” in land are most likely treated differently than defects in an existing building.
Bottom line, I’m sad to say, is that you may need to bite the bullet. Hopefully, you got a good deal on the lot and the $10K bite is not so bad.
JM says
Buried Debris Causing Foundation Damage & Sink Holes
I’m on the Board of a Homeowners Association of a Townhome complex that was built in 1976 on top of a razed woolen mill built in 1888. The debris was not carted away, but left in place and filled. Over the years, many sinkholes have formed, which have had ‘temporary’ fixes of filling with sand. We’d like to find a better longer-term solution.
Recently, we have one garage that has settled due to a new sinkhole forming underneath it. An engineer is proposing demolishing its foundation and inserting 17 helical piles to support a new foundation. The bids we’ve received to do the work cost around $90K, which seems like an expensive to a small problem. We can’t afford to replicate this solution as problems crop up elsewhere on our property.
I’ve read about flowable fill, and want to investigate that as an option. Who should I talk to to get such an evaluation?
Are there other things you’d suggest? Is there someone I can contact to get a holistic evaluation of our property? The current plan is focused only on this one garage, and I’m concerned his fix may cause problems elsewhere. Environmental/conservation-commission issues are always present, as we sit right on the edge of the original mill pond, surrounded by wetlands.
John
buildingadvisor says
Sorry to hear about your situation. Rehabilitating such a large and variable debris field after the area was developed is difficult and expensive. A “holistic” approach that will treat the entire site is certainly something to consider, but it might be prohibitively expensive and may treat areas that were not going to fail. However, treating individual structures for $90,000 each could also break the bank. And this is just a garage; the costs for a failing house foundation would likely be much higher.
You definitely need the help of a highly experienced soils/geotechnical engineer to inspect the site and propose a solution. The engineer will write the specifications for the contractors to follow. Each contractor (and engineer) might have specific techniques that they prefer, so make it clear that you need the most cost-effective approach that will work over the long term.
If the site issues were addressed by the original contractor, you would not be having these problems. He would have excavated the area to reach undisturbed soil and then replaced it with suitable compacted fill. Doing this after the buildings are completed is nearly impossible, so you are left with a host of engineered solutions that are more than band-aids, but less than ideal.
Conceptually, you have two main options:
• Reinforce the weak soils so they can support the structures above, or
• Reinforce the foundations so that they can support the structures on soils of weak and uneven strength
Most likely, you will use some combination of these two strategies.
Every poor building site is unique and needs individual assessment. Analyzing this site will be difficult and expensive and will require a number of test borings and possibly other high-tech instruments used to measure subsurface conditions. But without good data, you will simply be waiting for individual buildings to fail and addressing them one at a time.
I suspect the optimal solution will involve a number of techniques. These include:
• Filling the sinkholes and voids with stable materials for rebuilding: stone, gravel, soil, foam, grout, flowable fill, or concrete where needed.
• Raising existing slabs using slab-jacking techniques with either mud (sand, soil, water, and cement as needed), foam, or grout.
• Reinforcing existing slabs and foundations with helical piers
• Reinforcing or rebuilding existing slabs with structural slabs supported by grade beams, often sitting on piles or helical piers that reach down to stable subsoil.
• Excavating areas of unstable soil and backfilling with layers of suitable fill.
The foundation type, building loads, and soil bearing capacity need to be matched to ensure a stable building. Specifically, the rehabilitated soil beneath the building must have a bearing capacity that can support the building loads above transmitted to the soil by the foundation. Standard residential foundations typically require soil with a minimum 1,500 psi bearing capacity.
The required soil strength will depend on the type of foundation, along with the size, thickness, and steel reinforcement used in foundation components. The soil strength will be determined by the type of fill materials used, compaction performed, and continued existence of voids, debris, and other unknowns. Engineered fill materials, such as flowable fill, can usually be modified to provide the strength required.
This is complex work that should be specified and inspected by an experienced engineer. The engineer can probably recommend local contractors that they trust.
Which approach is most cost-effective will depend on the cost and availability of fill materials and skilled labor in your area.
Helical piers are one of the more cost-effective approaches to supporting and stabilizing loads in variable soil conditions. They have become very popular with deck builders in recent years, but have many other uses.
Whatever approach you use, get more than one bid. Have the work inspected by the engineer. And get an ironclad warranty that the repairs will last.
Best of luck!
Steve
Read More on:
Buried Agricultural Waste, Building On
Buried Debris, Erosion, and Foundation Damage
Buried Rubble, Building On
Cracks in Slabs, Causes & Cures
Expansive Clay Soils and Foundation Damage
Filled Land, Building On
Poor Soils, Building On
Poor Soils, Who Pays Extra Costs?
Soil Washed Away Under Foundation Corner
C.O. says
Can’t Build Pool Due to Poor Backfill Not Disclosed by Builder
While digging to build a pool for our 3 year old house, the contractor found unsuitable debris due to backfill left from the builder. 16 feet and they still found backfill containing organic matter. The soil engineers said they would not continue. It was not disclosed by the builder that the yard had extensive backfill and could not be build on. Should this have been disclosed to us?
buildingadvisor says
Sorry to hear about your situation. In most states, sellers are required to disclose “material” defects that they are aware of – that is, defects with a large effect on the value of the property. Some states exclude “patent” defects which are plainly in view to anyone making a reasonably thorough inspection. For example, a visible pile of junk cars would be a patent defect.
Under this principle, I believe the sellers should have disclosed the uncompacted fill with buried debris if they were aware of the condition. Perhaps burying organic debris in uncompacted fill is standard practice of this builder and he does not consider it a “defect”.
Unfortunately, the only was to get compensation for the defect or to correct it by excavating the site and placing new compacted fill would be to sue – or at least begin the process of litigation, hoping for a settlement. A lawyer can advise you about the costs of litigation and the likelihood of success.
In general, litigation is expensive, slow, and stressful, so you need to be prepared for a long and difficult effort if you go this route. If arbitration is an option, that can be somewhat quicker and less costly, but the outcome is often a compromise.
You can read more about disclosure of defects at this link.
James Cook says
Is It OK To Pour a Slab Foundation on Uncompacted Fill?
Recently the Town I live in purchased an old hotel, knocked down the building and filled a foundation hole about 8-10 deep They did not have a compactor on site and used an excavator to fill the hole. They plan to build a slab on grade for a new Town Hall. Do you see a problem ahead?
buildingadvisor says
It is absolutely a bad idea to build a slab foundation over 10 feet of uncompacted fill. You sometimes hear about “self-compacting” fill, but this is a myth except for certain types of low-strength “flowable” fill specified by engineers for limited applications.
For residential and light commercial construction, fill should typically be compacted in 8-inch lifts — or as specified by a soils engineer. Hand-held compactors can be used for small areas. These are typically vibrating plate compactors for granular fill or impact machines such as power rammers for cohesive soils with high clay content. Various types of heavy rollers are used for larger areas.
Waiting for soil to settle from rain and gravity, and to ultimately self-compact, is an unreliable approach that can take years or decades. Now that the damage is done, I’d recommend getting a soils engineer to evaluate the situation and oversee any attempts to build on the filled area. There’s always a solution — such as a heavily reinforced slab with piers or piles as needed.
But it would have been a lot cheaper to compact the fill in the first place.
Philip Malt says
Is Former Dirt Pit Buildable?
Hello, and thank you for this fantastic website!
I am looking at a parcel of land that is for sale. The land is currently a dirt pit. It has large “pits” or holes where the dirt has been dug out and used to fill in at construction projects. The land has 5 large holes made by an excavator that fills up dump trucks digging down to maybe 20 feet, and the pits are now sometimes 40 feet across. The lot is not buildable without filling these in. The only land they did not dig up is the road on the property they park the excavator on to take the dirt out. There is a bit of water down at the bottom of some of the pits as well.
buildingadvisor says
The simple answer is yes, you can probably build on this land if it is properly filled with compacted material. If the material is poor quality or not compacted properly, you will have excessive and uneven settling, which can lead to serious structural problems.
With this much fill, I would not proceed without a civil, soils, or goetech engineer’s assessment of the site and a cost-estimate for buying and installing the fill. The cost of high-quality fill varies greatly depending on what is available locally. Essentially, you will be reversing the work of the current owners who removed the soil.
The engineer may also recommend a more heavily reinforced foundation that can support the required loads on less-than-perfect soil conditions.
So, no, the site is not DOA, but will cost a lot more to develop than one with favorable soil conditions.
You can read more at these links:
Buried Debris, Erosion, and Foundation Damage
Buried Rubble, Building On
Cracks in Slabs, Causes & Cure
Cracks in Foundation Walls, Diagonal
Poor Soils, Building On
Poor Soils, Who Pays Extra Costs?
HP says
Buying a Townhouse Built Over a Filled Ravine
We are looking at a house built 2006. Is the building still settling? It’s built over a ravine that was fillled in with dirt and gravel when built. No structural damage is evident, but a little settlement of the house is obvious in the slight slant of living room. No other noticeable settlement. Is house safe to purchase?
buildingadvisor says
Any house foundation built on fill may be subject to uneven or excessive settling. But the risk is greater when building on fill – and especially for fill on a steep site. It is difficult to get adequate compaction on a steep slope such as the edge of a ravine.
The degree of settling will depend on the quality of the fill, its bearing capacity (strength to support a load), and the location and size of the of house loads that bear on the soil.
To guard against significant settling, it is important that the contractor use suitable fill materials under a home, and compact them properly. Sometimes, corners are cut due to the cost of quality fill and the labor and equipment required to properly compact the fill.
It’s possible that the “slight slant” in the living room is caused by framing errors, wood decay, or shrinking lumber, rather than foundation problems so that needs to be checked out as well as the foundation.
Assuming that the slope is caused by foundation settlement, and the house was built 16 years ago, most likely the soil has fully settled and you won’t experience additional problems. However, there’s always the possibility that the foundation movement is caused by a current problem, such as subsurface water eroding the soil under a footing. Also, extreme conditions such as heavy rains or a small earthquake could trigger additional soil movement.
An important clue will be whether other townhomes in the development, especially those adjacent to this unit, have experience similar problems. Check with the neighbors and check with the homeowner’s association.
Bottom line: Most likely, you will not experience additional settlement, but to be safe, have the building assessed by a structural, soils, or geotechnical engineer to identify the source of the problem and any required remediation. Make this a contingency of your offer.
You can read more on the topic at these links:
Building on Concrete Rubble
Soil Washed Away Under Foundation
Buried Debris, Erosion, and Foundation Damage
Buried Rubble, Building On
Poor Soils, Building On
KM says
Should We Build on Site With Buried Rock, Trees & Debris
We are getting ready to build on a 4-acre oil drilling pad that was never used. A neighbor just told us that the trees they cleared were buried in holes dug by an excavator lengthwise across the pad. Also, they brought in many many many loads of rock type of material.
They had heavy equipment, including graders, bulldozers, sheepsfoot, other compactors, and big soil mixers. What little I saw they were mixing, rolling and leveling with graders. It looked like they might have even brought in lime to mix but I cannot be sure.
Since we are looking to build a post-and-beam structure with a concrete slab. how can I be sure the foundation will hold up, and know where the debris was buried. Any advice will be helpful.
buildingadvisor says
I’m not familiar with oil pads as they don’t drill for oil in my part of the world, but the issues are similar on any industrial site, including the possible cleanup cost for toxic waste discovered on the site..
In general, it’s risky to build on a filled site, unless you can confirm that the fill was good quality material (sand, gravel, crushed stone, etc.) that was compacted properly — probably not the case here. For one thing, buried trees are going to decay over time and leave voids, leading to uneven settling.
If you can find a portion of the site where the soil was undisturbed, that would be your best choice for a home site.
Otherwise, I wouldn’t build there without a soils engineer inspecting the site and spec’ing out a foundation that would work. That might mean over-excavating and adding good compacted fill, or building a structural slab with lots of extra rebar so it can span over the weak spots in the base. People sometimes use reinforced grade beams, driven piles, or helical piers for building on questionable soils. Unless this is the perfect building site at a great price, you may want to keep looking.
Read more on building over Buried Debris and Poor Soils
Suzi says
Lawsuit Over Filled Land?
I was sold land that I am building on. The basement has been dug out and now my excavation contractor has found out that 23 feet is filled land. I have to get an engineer to determine if I need steel beams instead of block. I’m wondering if I could sue for the extra costs of my home?
buildingadvisor says
There are a variety of technical solutions to build safely on filled land and you are smart to hire an engineer to specify and oversee that portion of the project.
As for suing to recover the added construction costs (or reduced value of the land), that is a possibility. Disclosure laws for real estate vary from state to state and may be different for land vs. an existing home. About 30 states require sellers to disclose known defects in vacant land they offer for sale. The key is proving that the seller knew about the defect and intentionally withheld the information.
In other states, land is generally sold “as is” and it becomes the buyer’s responsibility to investigate the land thoroughly under the age-old principle of “Let the buyer beware.”
The language in your Purchase & Sales contract also comes into play. If the seller specifically warranted that the land was free from buried debris or whatever defect you discover, then you have grounds to recover your losses or even to rescind the sales contract.
Regardless of state law and your specific sales contract, you still have grounds to recover if you can prove that the seller committed fraud, that is intentionally lying to make the sale. The legal self-help publisher Nolo.com defines fraud as “intentionally deceitful or misleading words or actions that wrongfully benefit the perpetrator of the fraud at the personal or monetary expense of another.”
These are legal questions and I am not a lawyer. I’d recommend getting the opinion of a lawyer with extensive experience in real estate litigation. He or she can help you determine whether you have a strong legal claim and whether it would be cost-effective to sue. Small Claims Court might be another option to explore.
See also: Foundation Damage From Buried Debris