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Wednesday, May 24th, 2017 by Braden Cook
This installment in the "Foundation Repair series" is going to be a little different than the other two blogs about foundation problems. Since there is so much information and different solutions for each of these problems, there will be at least two different blogs talking about the solutions for the different foundation issues. This one will only go over foundation settlement solutions.
First we will start off with the solutions that do not work, then go into the ones that do. One option you have when you foundation is settling is a total foundation replacement. This is exactly what it sounds like, the dirt around your home is excavated like a archeaological dig site, your home is raised above the ground, and then a whole new foundation is poured for your home, and the dirt is replaced. This seems like a good plan, right? If the foundation is broken, we should just replace it. While this kind of makes sense, it is a flawed way of thinking. This is because even though the foundation is broken and settling, it is not the problem. The issue is the soil around and beneath your home. So this solution is only temporary, even though the cost is huge. This is definitely one solution that you don't want to try.
Another solution that you should be wary of is concrete underpinning. This may be something that you've never heard of so we'll go over exactly what it is. This solution starts off similarly to the last, the crew begins by excavating the soil around your home, then pours larger footings beneath the existing ones. The soil is then put back into place. The reasoning behind this method is because the footings are meant to hold the weight of the home, therefore if the footings are larger and cover more area, the weight of the home will be more spread out. This method generally does not work because the new concrete footings are not poured outside of the "active zone" (the active zone is the area around the home in which the soil is still settling). This again, does not address the underlying of the issue and will only cost more when it needs to be repaired.
We still have one more bad "solution" to go over, concrete piers. These piers are pushed into the ground and held together by a wire. A shim is then placed on the top of the tower of concrete cylinders in order to hold up the home. This is not the worst solution out there, but it does not work too well because of how wide the pillars are. It is very difficult to push down these concrete blocks through the soil, and concrete is known for breaking and cracking when under immense pressure (like holding up a house) and during temperature changes.
Now onto the real solutions! The first actual foundation settlement solution is to install steel push piers. If you have checked out any other content on our website, you have probably seen these push piers. The push piers are are steel rods that are driven deep into the soil to either bedrock or a stable soil layer. While these push piers can be installed both in-and-outdoors, we generally only install them outside the home. These piers are attached to a large, steel bracket that is secured onto the base of your foundation. After all of this is taken care of, the push piers attempt to lift the home back towards its original position, raising the home and closing gaps in and outside the home. The reason these push piers work is because it helps to solve the actual problem, the soil. The piers are driven much further than the still-settling soil until it reaches a stable soil layer. This means the weight of the home is transferred from the "loose" soil around the home, to the sturdy soil deep beneath the home.
The last real solution are helical piers. Helical piers are a very similar concept to the steel push piers, except the are a little more versatile. The helical piers have helix shaped blades on the shaft of the pier, which provide more support and easier installation. One thing that helical piers do that are much better than the normal push piers are that they help to stabilize lighter structures (like decks or stoops), as well as homes and other buildings. The table included below shows off exactly what each of these methods are capable of.
As previously mentioned, this is part one of the "foundation repair solution" blogs. Look out for more parts talking about the solutions for sagging floors and wall failure that will come up soon!