The Perfect Retaining Wall Part 2
The Value of a Foundation
It doesn’t really matter if you build the strongest retaining wall that is available (I think that we do) if you have a less than desired footing, then you will have a less than substantial retaining wall. This is not to say that your wall will fall overnight, but if you have longevity in consideration, then you will undoubtedly be disappointed in the future. This is why a proper footing is so very important.
In the absence of an engineer, a general rule for a footing in our region is that a footing will need to be half the height of the wall in depth, and a minimum of the thickest portion (most likely the bottom) of the wall. This is a worst-case scenario. There are different types of soil, and therefore, different types of footings.
The worst that we have is clay. Clay is a retaining walls’ worst nightmare! It drains poorly, which increases hydrostatic pressure. Clay swells incredibly when saturated, and shrinks most profoundly when dry. The footing for this type of soil must be substantial, otherwise, this retaining wall will push over from the top, wash out under the bottom, or push the whole wall out. The addition of toes, cantilevers, and heels on this type of soil is a good consideration, but an engineer is a must. They will design a wall that will serve you well not only for your life, but for the rest of your home’s life, and maybe beyond. Let me explain why this is so important:
Last year while I was traveling, I got the divine pleasure of sitting next to a British man on the plane. We had all kinds of discussions ranging from the difference in fuel mileage for cars to property value. The biggest difference with the value of property in Europe and here was their citizens’ outlook on longevity. This man’s home was four hundred years old, and in his mind, it was going to be lived in by his descendants for centuries to come. As Americans, we have this idea that it does not matter what happens to our property when we are done with it. We have not experienced this type of demand for space, but when you think of it, why not get a product that will last the course of time? This is why we think that our retaining walls are so valuable. Build your wall one time, and I promise that you will save money in the long run.
In the absence of a geographic test to determine the levels and soil types, and how deep your bedrock is, you could prepare for the worst, and build a retaining wall that will stand up to clay. If you have a sandy type of soil, however, the difference in price for the footing alone will easily pay for this type of testing. If you find the worst, then you can be thankful that you will have a great wall that will stand the test of time. Whatever type of soil, hydrostatic demand, or other challenges that you might face, a proper footing will do nothing but help you fight the test of time, and hopefully, win.
If you have other questions about retaining walls please visit our web site: http://www.adcokc.com
If you found this information helpful, or if you have more important information, please feel free to comment. Good luck!