Tie back systems are used when your foundation wall is pushing inward. The pressure of the soil pushing against the foundation wall is greater than the concrete and steel wall can retain or hold back. A structural repair must be made in order to stop the foundation wall from moving inward any more. Some tie back systems can pull the wall back plumb but excavation of the entire wall must be done. A void must be present for the wall to move back into place. Most foundation wall should be pulled back if they are greater than 5 degrees or 3 inches out of plumb. There are many different tie back systems now being installed. Some systems are better than others. It is important for the homeowner to understand how each system is installed and how they work.
What causes lateral movement?
First you must understanding what is actually pushing your foundation wall in. The Active Zone of Soil is the force that is pushing your wall inward.
Now that you know what dirt is pushing your wall in, lets figure out how much force the tie back system needs to hold back. The amount of weight or force can be figured out by having some basic information. You can use the weight chart below to figure out what type of soil you may have around your foundation.
If you know what type of soil you have around your foundation, than let’s measure the height of your foundation wall. Hint: (The average height is 8′)
Use the Foundation Height and Weight load chart to figure out how much weight is pushing against your foundation wall 1 foot wide for the entire height of your foundation wall.
After selecting the Pounds per Square Foot (from the box) multiply that number by the height of your foundation wall. Now you have the amount of weight that is pushing against just 1 linear foot of your foundation wall. If your wall is 40′ you can see that is a lot of weight pushing against your foundation.
Once you know why your foundation wall is pushing inward, it is easier to understand why most tie-back system’s fail. Most homeowner want a permanent foundation repair. Having to come back and tighten nuts is not a complete foundation repair. If your basement is finished removing drywall every time is not a very good option.