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A-1 ENGINEERING, LLC

  A-1 ENGINEERING, LLC                      

Structural + Civil Engineering Consultants                             Serving San Antonio and Austin

Foundation Surveys Help Home Owners Monitor Foundation Problems

HOME OWNERS - Monitor the performance of your foundation.

The most costly problem for new houses and old houses ? even multi million dollar custom homes ? is foundation problems. More specifically, after a new house is built, the foundation may move and cause damages to the brick, concrete, tile, walls, and doors and windows; and sometimes structural damages, which are very difficult to repair. 

The most effective way to start monitor how your foundation is performing is by getting a foundation elevation survey. A foundation elevation survey is not the same as the property survey you get when you buy the property. The foundation survey is specifically for the floor of the house. The structural engineer takes readings across the floor and records it onto a floor plan to show the differences in readings. 

The readings alone may not mean anything now, BUT, if you start seeing cracks in your walls, doors do not work, windows are broken, the walls are cracking or if you have plumbing leak, then the foundation survey will help your structural engineer prove to the home warranty company or home insurance company that your foundation has moved and has problems. 

Please Also read about Custom Home Builders Foundation Designs

Contact us to learn more on how we can help or speak with a Texas Structural Engineer

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New Foundations are not Constructed Perfectly Level or Flat

Many people have the misconception that a newly built foundation is flat or level. The truth is the instant that the concrete foundation is poured, that foundation is built with some highs and low. It doesn’t matter if the home builder is a production home builder or a new home custom builder or build on your lot builder, or if the house is $50,000 or $10,000,000; the foundation will never be constructed perfectly level; or like we say, zero inches of difference between two points will never be achieved. 

It is a construction fact. Now, we do agree that some builders may build a foundation that is closer to being flat than other home builders, but the point we’re trying to make is that the foundation will never be flat from the very beginning just because of the way a concrete foundation is built.

However, there’s also another main reason why a foundation is never flat and that is that as walls and roofs and bricks and other finishes in the house are being added; more weight over the foundation causes the foundation to settle. This is known as construction settlement, which is normal to some degree. So, if you were to take a foundation elevation survey throughout the house (i.e. if you determine the elevations of the foundation), you will never get exactly zero inches throughout. 

Foundation surveys help monitor the performance of the foundation. Consider this, you buy a new home and before you move in, you get a structural engineer to record the foundation elevation survey. You put it in your home warranty file. Five years later you start seeing a lot of cracks and you start to see some major concrete cracks in your foundation. The next move is to get the structural engineer to re-measure the foundation elevations on the survey. The structural engineer can then compare the differences in reading and help you understand where and why the foundation is moving. Better yet, if you have a home warranty or builders warranty that covers foundation problems, then this data will help you prove your case with the warranty company. 

How to Foundation Elevation Survey Helps You: Scenario No. 1

Suppose that you buy a house or build a new house, and after a few months or years you start seeing cracks in the walls or ceiling, or floors, or brick. If you’re house is less than 10 yrs old, then you call the home builder (if the builder hasn’t gone out of business), and he will send someone to your home which usually will do an elevation survey of your foundation by taking elevations at different spots throughout the house.

The answer from most of these warranty companies and builders is that the measured elevations from the foundation survey prove that the “movement” is within tolerance. That is almost always their answer.

Now, let’s apply common sense: How can you do a Foundation elevation survey and measure elevations and claim that the foundation has moved within tolerance if you have no idea what the starting point was? You have absolutely nothing to compare the measured elevations to, so how can a builder or warranty company (or a foundation repair company) say that a foundation has moved within tolerance? Only if the foundation was zero inches to begin with would you be able to make such a statement, but as we have explained, the foundation after construction is never zero.

What if your house is older than 10 years (or the builder has gone out of business), who would you call? Most people would get “free” quotes from a foundation repair company. A foundation repair company would do exactly the opposite, they would do a foundation survey and take elevation measurements and conclude that the house foundation has moved more than Zero and so you need a repair and so many press piles. (More on Foundation repair deception in our article for Foundation Repair Austin and Foundation Repair San Antonio).

How does a Structural Engineer Determine if a Foundation has moved?

There are multiple ways that engineers analyze foundation movement. The most common method or guide that Texas structural engineer use is the American Society of Civil Engineer - Texas Section, Guideline for the Evaluation and Repair of Residential Foundations

The guideline is not a "Code", but a guideline. The guideline helps all engineers standardize the way foundations get evaluated. This means that a structural engineer from Austin, Texas should evaluate the foundation the same way a structural engineer from Houston, Texas would; if they follow the guideline. 

The guideline provides two analysis that should be done:

1) Calculate Overall Foudnation Deflection

2) Calculate Localized Foundation Deflection

3) Calculate Overall Foundation Tilt

For those of us that have read engineering reports from warranty companies, you will notice that most warranty companies only focus on overall foundation deflection. Why? Because your foundation will most likely be within the tolerances set in the guideline. Most warranty companies will not run a localized foundation deflection analysis. So who does? A-1 Engineering analyzes the foundation for all three criteria.

Foundations with major foundation problems may be okay for overall deflection but they will likely fail in localized deflection; which the warranty company will not want to get analyzed.

Benefits of the Foundation Elevation Survey

Doing a Foundation Survey saves you money indirectly, and most importantly saves you from making a costly mistake. Here’s why:

First, if you have a house that is still under warranty, the Builder may claim that the foundation is within tolerance if it moved; it would be his word (actually, the word of a Structural Engineer hired by him) against the word from the engineer hired by you (see more on lawsuits on the next subchapter). 

And that is because you don’t have a factual record; a foundation elevation survey, actually showing where the house elevations started out. You would lose money potentially in the sale of the house and lose money in a potential foundation repair. Thousands and thousands of dollars lost by you just because you didn’t spend a few hundred dollars on a foundation elevation survey from the beginning… a very costly mistake.

Second, if your house is out of warranty, then you’ll call a foundation repair company and they will claim that your foundation is moving so much that it is structurally unsound (how do they, not being structural engineers, claim to know if a house is structurally unsound? 

More on Foundation repair deception found in the articles for Foundation Repair Austin and Foundation Repair San Antonio). 

Some movement of the foundation is acceptable; even when you think you have large cracks. But most importantly, there are hundreds of different reasons why you may have cracks in your house, and they may have nothing to do with foundation movement. 

When you have a foundation repair company show up, they can’t tell you that the foundation moved if you have a record showing that the foundation hasn’t moved compared to the original foundation survey and therefore they can't sell you many press piles that you probably don't need.

It’s simple math, “save” a few hundred dollars by not doing a foundation elevation survey, and in return you might have to spend thousands of dollars in the future. Or, spend a few hundred dollars now, and potentially save thousands of dollars later.

When to do a Foundation Elevation Survey

The most qualified person to do a Foundation Elevation Survey is an Engineering company who designs foundations and the structure above it.

Structural engineering companies have the personnel trained and qualified to do these kind of surveys. The surveys are verified and signed sealed by a licensed Structural Engineer. 

The best time to do a foundation elevation survey is right after they are done building the house. Ideally, anything within 12 months after construction is still acceptable and fairly accurate.

If you just bought the house, but the house is not new, then the survey is still very helpful to establish a baseline; but, it will not obviously reflect the conditions of the foundation immediately after construction. To be safe, the accepted rule is to always perform a foundation survey regardless of the age of the house because you establish a benchmark for future comparisons.

More on Foundation Surveys, see Foundation Surveys Frequently Asked Questions

Please, contact one of our offices, we do Surveys in Austin, San Antonio, and across Texas. We are Structural Engineers Austin and Structural Engineers San Antonio.