Expansive Soil Foundation Problems (how much, buying a house, buying)

[Capitalprophets]

We were interested in buying a house and the inspector recommended to hire a structural engineer to look at the foundation more closely. The structural engineer came and told us the beam on far right of the house has a crack due to stress because of inadequate watering. The cracks are seen from the front of the house in the garage floor into the bathroom floor tile. There are cracks found in the front of the house in the bricks, couple of windows are cracked. The owner has installed french drains and corrected grading.

The structural engineer said he'd rate this house 6 to 7 on a scale of 10. He wouldn't say if I should proceed with buying or not because they just dont do that. He also said to install the root barrier which can cost about 12K which could fix this issue but it adds up.

The engineer said its mostly because of the expansiveness of the soil and the the tree not helping sucking the moisture out of the soil by about 250 gallons per day.

We really like the house but not sure if to proceed, the house is priced appropriately. I'm not sure how much of this is a typical problem with expansive soil issue in Texas. Is this pretty typical on a 11 yr old home?

Any help?

[Ice_Major]

Originally Posted by Capitalprophets

We were interested in buying a house and the inspector recommended to hire a structural engineer to look at the foundation more closely. The structural engineer came and told us the beam on far right of the house has a crack due to stress because of inadequate watering. The cracks are seen from the front of the house in the garage floor into the bathroom floor tile. There are cracks found in the front of the house in the bricks, couple of windows are cracked. The owner has installed french drains and corrected grading.

The structural engineer said he'd rate this house 6 to 7 on a scale of 10. He wouldn't say if I should proceed with buying or not because they just dont do that. He also said to install the root barrier which can cost about 12K which could fix this issue but it adds up.

The engineer said its mostly because of the expansiveness of the soil and the the tree not helping sucking the moisture out of the soil by about 250 gallons per day.

We really like the house but not sure if to proceed, the house is priced appropriately. I'm not sure how much of this is a typical problem with expansive soil issue in Texas. Is this pretty typical on a 11 yr old home?

Any help?

Foundation issues are typical for the metro. Certain areas get it worse than others. Comes down to the soil type. With the unusually dry weather, means many homes are going to experience foundation issues. It is a good thing you hired a structural engineer. Is it possible to have the seller drop the price to accommodate the cost of foundation repairs?

[escanlan]

Originally Posted by Capitalprophets

We were interested in buying a house and the inspector recommended to hire a structural engineer to look at the foundation more closely. The structural engineer came and told us the beam on far right of the house has a crack due to stress because of inadequate watering. The cracks are seen from the front of the house in the garage floor into the bathroom floor tile. There are cracks found in the front of the house in the bricks, couple of windows are cracked. The owner has installed french drains and corrected grading.

The structural engineer said he'd rate this house 6 to 7 on a scale of 10. He wouldn't say if I should proceed with buying or not because they just dont do that. He also said to install the root barrier which can cost about 12K which could fix this issue but it adds up.


Did the Engineer recommend any foundation repairs or just the roof barrier?


The engineer said its mostly because of the expansiveness of the soil and the the tree not helping sucking the moisture out of the soil by about 250 gallons per day.


A root barrier will only help (not totally prevent) roots from reaching to the house where they can grow under and cause additional problems. Tree roots spreading are a result of the tree not obtaining enough water near itself and reaching to the water source which would typically be the flower beds around the house and soil watering provisions around the foundation. You can place all of the root barriers you want but the tree will still draw water away from the foundation unless you increase watering to handle the issue. You can see this effect by looking at a mature tree and surrounding ground that is not watered. The water is drawn from the ground forcing grass and other plantings to go dormant and/or die.


We really like the house but not sure if to proceed, the house is priced appropriately.


Is the home "priced appropriately" to account for the following?

• Any needed repairs to the foundation if called for? Keep in mind that even if you re-hydrate the soil and place root barriers or remove the tree the foundation may not lift back on its own. That is something you would need to deal with later when you choose to sell the home.
  
• During foundation repairs whether it is actual underpinning or re-hydration of the soils moving the foundation back in place can cause additional cosmetic and other damage. Have you accounted for a "reserve" amount to handle this?
  
• Installation of the root barrier?
• Repair of any existing cosmetic damage?
  
• Cost of additional water to re-hydrate the soil and keep the soil hydrated due to a tree in close proximity?
• If the tree continues to be a dehydration of the soil issue it may well need to be removed. Have you priced out its cost and factored that into a "reserve" amount?

I'm not sure how much of this is a typical problem with expansive soil issue in Texas. Is this pretty typical on a 11 yr old home?


The age of the home plays no part in this type of issue. These issues occur very frequently in this area to homes of all ages.


Any help?

Thoughts in blue above.

[tewest86]

I would contact a Geotechnical Engineer. We design foundations. A few $1000s now could save you more later on.

[escanlan]

Originally Posted by tewest86

I would contact a Geotechnical Engineer. We design foundations. A few $1000s now could save you more later on.

What is it that a Geotechnical Engineer is going to do during the purchase of a home that costs ""a few $1000s"?

[bpollen]

Are those trees close to the house? If so, they need to be cut down. You may not need the root guard, if yu do that.

If you find an older home, getting a pier & beam is better with that soil...if the house has stood the test of time. Any newish house with a slab has a risk of developing foundation problems.

[tcualum]

Does the house have a foundation watering system? It probably doesn't if the foundation is inadequately watered. If not, you need to add one of those too. I would also get another opinion to make sure that the solution will work. I once got 3 consultations from different engineers and each one had a different solution.

I would consult an arborist about the tree. They will be able to tell you if the tree needs to be taken down or if the root barrier is enough. My landscaper is also a certified arborist. There were some problems with some stone stairs in our retaining wall. He looked at the problem and he discovered that a self-rooting tree was causing part of the problem and another tree was planted too close to the wall. We had to remove the self-rooting tree but we were able to save the larger, more established tree by cutting back the roots and moving the stairs. I was really glad we could save the bigger tree because it provides a ton of shade and is huge for this area. An arborist will be able to provide solutions to the tree issue that might not occur to a structural engineer.

[tewest86]

Originally Posted by escanlan

What is it that a Geotechnical Engineer is going to do during the purchase of a home that costs ""a few $1000s"?

Well, first is time. Let’s assume $350 per hr. Second, he would run a few tests to determine soil type. Then develop a report. If I was doing it, it’ll be $1,500-$2000.

[escanlan]

Originally Posted by tewest86

Well, first is time. Let’s assume $350 per hr. Second, he would run a few tests to determine soil type. Then develop a report. If I was doing it, it’ll be $1,500-$2000.

Buyers can easily use the USDA WEB Soil Survey site located here to determine the soil type https://websoilsurvey.nrcs.usda.gov/app/ . The only way the soils are going to change under a home from what is provided here is if they have been excavated to a depth that was engineered to replace the expansive soils. That is rarely done in residential construction.



If the buyer wants to go a little farther to better understand how soils affect the foundation they have numerous publications available on the Foundation Performance Association WEB site located here https://foundationperformance.org/ . Even though this is an engineering site they have publications written specifically for the general public. There are also many other WEB sites that discuss expansive soils as well as other soil types.



So for the benefit of buyers, and my own edification, what value would the $2000.00 report on the soil the home is placed on provide toward the home purchase?

[tewest86]

Originally Posted by escanlan

Buyers can easily use the USDA WEB Soil Survey site located here to determine the soil type https://websoilsurvey.nrcs.usda.gov/app/ . The only way the soils are going to change under a home from what is provided here is if they have been excavated to a depth that was engineered to replace the expansive soils. That is rarely done in residential construction.



If the buyer wants to go a little farther to better understand how soils affect the foundation they have numerous publications available on the Foundation Performance Association WEB site located here https://foundationperformance.org/ . Even though this is an engineering site they have publications written specifically for the general public. There are also many other WEB sites that discuss expansive soils as well as other soil types.



So for the benefit of buyers, and my own edification, what value would the $2000.00 report on the soil the home is placed on provide toward the home purchase?

That site uses interpolation to fill in the gaps. I've designed 100s of foundations and developed 100s of reports. You can't mitigate something if you don't know what you're working with. It will give you a better understanding of the risks involved. It's up to the potential home owner to decide to accept those risks or move on.

The lack of a proper foundation design is why we have these issues in the first place. The Contractors were too cheap to get proper soil testing and prepare a suitable foundation. You're about to make the biggest purchase of your life and you're harping on $1000-$2000 additional dollars so that you can be more informed before making your decision.