Dawson Foundation Repair
Dawson Foundation Repair
Dawson Foundation Repair

214-234-8421 (Dallas)
713-668-2110 (Houston)
1-800-368-7662
Menu

Methods of Foundation Repair

Below is a comparison of the four major methods of foundation repair used in Texas. While each has its advantages and its disadvantages, a side-by-side comparison of Dawson’s Bell Bottom Pier method clearly demonstrates that it is the most reliable way to solve a home foundation problem permanently. This method is proven and has been tested over time. This is the same building concept used to build support columns for bridges and highway overpasses. And the following link will help you compare the true cost of foundation repair. When you get the facts, you can be confident in your decision to trust Dawson Foundation Repair.

If you would like a more technical examination of each of the methods of foundation repair, check out ADSC’s (The Association of Drilled Shaft Contractors) article Potential Heave in the Pressed Concrete & Pressed Steel Piles in Residential Foundation Construction which details serious problems with piling methods in the Dallas metroplex area and how they can damage your home’s foundation – or take a look at the conclusions of PhD recipient Tom Witherspoon made in Load Capacity Testing and Analysis of Residential Underpinning Systems in Expansive Clay Environment.

The Bell Bottom Pier Method
The Pressed Piling Method
The Pressed Piling With Inserts Method
The Steel Piling Method

 

Bell Bottom Pier Method

At Dawson Foundation Repair, we have built a company and a reputation since 1984 by providing a long-term solution for concerned homeowners. Our work is backed by our years of experience, a lifetime service agreement, and hundreds of foundation repair testimonial letters from our satisfied customers. We know that Bell Bottom Piers is the superior to all other  methods of foundation repair because we install it every single day and have seen it perform time and time again.

The bell bottom pier method is the only thoroughly researched concrete slab repair method on the market today. This pier design – poured concrete reinforced with steel rebar – is the same conceptual pier design used in the construction of commercial multi-story buildings, bridges, and highway overpasses. They can be installed in any of the soil and moisture conditions found in Texas and cope equally well from Dallas to Corpus Christi to San Antonio to Austin.

Dawson Foundation’s Bell Bottom Piers
The Proven and Permanent Solution
Bell Bottom Piers are the superior method of Foundation Repair

Advantages

The bell bottom pier method is a thoroughly researched and proven foundation slab repair method.
Your soil is tested onsite down to 15-18 feet deep for strength and condition.
The size of bell and depth of shaft will be custom designed for your house and will be between 8 and 15 feet deep depending on the depth of stable soil and other factors such as the presence of water, sand, or rocks.
The shape, size, and depth of bell and the angle of the shaft can be inspected.
Two layers of steel rebar are placed in the cap or upper portion of the pier.
High strength concrete is ordered from the plant for each house.
Three 1/2″ steel rebars are installed in the center shaft.
The footprint of the bell bottom pier is 380 sq inches – 13 times greater surface area than pressed pile methods –  solid support for your home’s slab.
Bell bottom piers anchor against uplift.
Safety factors are designed into each pier.
There are no damaging forces exerted on your house during installation.
The homeowner can move heavy items in the house and add new ones without concern for the foundation.

Disadvantages

There is an approximate two week waiting time required to allow the concrete to dry and gain full strength.
Improper construction will affect performance.

 

Click here to see a more detailed diagram of a Bell Bottom Pier

Click here to learn more about the History of the Bell Bottom Pier

Click here to see the step-by-step Foundation Repair Process

Pressed Piling Method

By far the most common of the methods of foundation repair is the Pressed Piling method. It is fast, cheap, and highly profitable for the repair contractor. They are installed all over Texas, but are particularly popular in places with soft, clay rich soil such as Dallas, Houston, Austin, and San Antonio. Pressed pilings are composed of a series of precast concrete cylinders which are installed by digging a hole under the house and then, by using the weight of the home as the driving force, the cylinders are driven into the ground. This method has two major drawbacks: the cylinders are not secured together in any way and the concrete slab is at risk of damage because of the driving process.

Because the cylinders are not secured, they cannot and will not resist horizontal movement, they can easily be pushed into the soil at an incorrect angle, and pilings can crack without being noticed during installation. Because the slab is used in the driving process there is no way to tell how deep the pilings will end up being pushed into the soil. This means that the pilings could reach a point of refusal (the point at which they can go no deeper into the ground) which is not properly anchored in stable soil. If not in stable soil, the pilings provide no benefit, but if an installation crew forces the cylinders beyond this point, they can crack the concrete slab foundation and cause major damage to the home.

The pressed piles or pressed piling method of foundation repair has many disadvantages and shortcomings

Advantages

There is no waiting for the concrete to cure.
The total job time is short.

 Disadvantages

It is an unproven repair method. There are no capacity tests in Texas soil conditions and long-term performance has not been established.
Typically no soil test is performed onsite.
The piling depth is limited by the weight of the house, so piling may not reach stable soil.
There is no steel reinforcement in the cylinders or cap.
There is no test of piling cylinder concrete strength. Usually it is batch tested only.
Cylinders broken during driving cannot be seen.
Piling misalignment cannot be seen.
There is no final inspection by city building inspectors.
There is no design safety factor for each piling.
Piling driving force may damage your house. (Your home’s foundation, its weight and strength, is used as a fulcrum to drive piles into the soil.)
Footprint of 6 inch pile offers only 28.3 sq inches – far less than the 380 sq inches of a Bell Bottom Pier.
Unconnected piling cylinders cannot resist uplift.

Click here to read Problems with Pressed Piles

Click here to read about Pressed Piles – Do they meet Building Code Requirements in Texas?

Pressed Piling With Inserts Method

The pressed piling method had so many problems that the people who employed it were forced to come up with ways to fix some of its many drawbacks. The pressed piling with inserts method was one of the variations they came up with. The pressed piling with inserts method uses the same basic technique as the pressed piling method, with one minor change: the concrete cylinders are reinforced in one of several ways (usually with a piece of rebar) to stabilize them as they are driven into the soil.

While this helped somewhat with individual misaligned pilings, the new method did not only fail to fix any of the other drawbacks of the system, but it introduced two new ones as well: Instead of having a single cylinder misaligned, the entire piling could now be skewed and moisture seeping into the gaps can cause the soil to weaken even further.

The pressed piling with insert slab repair method suffers many of the same disadvantages as the Pressed Piling method

Advantages

There is no waiting for the concrete to cure.
The total job time is short.
The cable or rebar inserted during driving helps alignment. It is of little benefit if inserted afterward.

 Disadvantages

There are no published capacity tests in
Texas soil conditions. The long-term foundation slab repair
performance is not established.
Typically there are no soil tests onsite.
The piling depth is limited by the weight of the house, so piling may not reach stable soil.
There is no steel reinforcement in the cylinders or cap.
There is no test of piling cylinder concrete strength. Usually it is batch tested only.
There is no design safety factor for each piling.
Cylinders broken during driving cannot be seen.
There is no final inspection by city building inspectors.
There is no design safety factor for each piling.
Piling driving force may damage your house. (Your home’s foundation, its weight and strength, is used as a fulcrum to drive piles into the soil.)
Footprint of 6 inch pile offers only 28.3 sq inches – far less than the 380 sq inches of a Bell Bottom Pier.
Water flowing down the central hole weakens the soil.

 

Click here to read The Truth about Pressed Piles

Click here to read about Pressed Piles NOT meeting Building Codes in Texas

Steel Piling Method

The steel piling method is similar to concrete pilings and attempts to use the strength of steel to overcome the weaknesses that arise with the concrete methods. Pressed steel pilings are primarily used in the Austin, Dallas, and San Antonio areas where conditions are dryer and soils are sandy or soils with harder strata between clay layers which would normally be the refusal point (the point where it takes more force to press the piling deeper than it does to lift the house) for concrete pilings.

Overall steel pilings are similar to the two other piling methods but with two notable differences. First, they have the benefit of being able to be driven deeper into the ground before refusal, which can be a major advantage in dryer soils. Unfortunately, they are frequently not pushed all the way to the refusal point, which means they could sag and fail to properly support the home. The other major difference is that the thinner pilings have less ability to resist the forces of shifting soil, especially upheaval, which can cause severe damage to a home’s concrete slab foundation.

The steel piling foundation repair method has numerous disadvantages and shortcomings

Advantages

There is no waiting for the concrete to cure.
The total job time is short.

 Disadvantages

Reliability varies with the season of the year in which the work is done.
Only perimeter installation is available.
No soil tests are performed onsite.
The piling depth is limited by the weight of the house, so pilings may not reach stable soil.
No onsite testing of piling strength is performed.
Piling misalignment cannot be detected.
Bending of installed segments upon installation cannot be seen.
No predicted design safety factor for each piling.
Not inspected by engineers or city officials.
Piling driving force may damage the house.
Unconnected piling segments cannot resist uplift.
Method creates a long-term loss of stability proven by experience and research.
Rearranging heavy items inside the home may cause foundation movements.

 

FREE Foundation Inspections

Remember, Dawson offers a *FREE foundation inspection for homeowners and commercial property owners (not involved in a real estate transaction).

For more information about Dawson Foundation Repair then please visit our About Dawson page.

And we also offer FREE foundation maintenance tips for all of our web site visitors.

Please visit our Frequently Asked Questions (FAQ) page for more information.