What is a Retaining Wall?

Retaining walls do more than make your property look aesthetically pleasing to the naked eye, especially with your wonderful garden. They’re carrying weight on their back that many people don’t recognize. 

Retaining walls are strong, independent structures that don’t need no help from anyone… sometimes. They carry the weight of the land so you don’t have to. We can say they carry the weight of the world.

Or at least, carrying the weight of the land sliding toward your property.

Dalinghaus Construction has not only repaired foundations for homes since 2015, but we’ve repaired our fair share of retaining walls in Southern California, Arizona, and Nevada. We’ve inspected over 10,000 properties, with hundreds of projects involving retaining walls. We’re no strangers to understanding what retaining walls are.

What is a retaining wall?

A retaining wall is a wall used to retain soil.

There’s your surface answer that doesn’t quite answer your question. Better yet, let’s explain what a retaining wall is used for.

These are types of walls you’ll find used on hillsides for planters, retaining soils, and they can be used in basements (basement walls are a type of retaining wall).

The main purpose of a retaining wall is to prevent the lateral movement of soil. So the soil on your property won’t invade the property of your neighbor.

You will also find retaining walls if you drive on a road. When you’re cutting into a hillside to make a road, you don’t want the dirt to move and mess everything up.

Before we proceed in educating on retaining walls, you want to watch this video answering the million-dollar question: What are Retaining Walls?

Different types of materials used for retaining walls

You’ll see various types of retaining walls all doing the same job. 

Masonry retaining Walls

You’ve probably seen huge block walls when you drive down the freeway or smaller walls in your neighbor’s house for their garden. Those blocks aren’t there for show; they’re doing their jobs as retaining walls.

These are gravity-based walls using the mass of the masonry material to retain the soil behind them. The mass of the blocks is determined by the amount of lateral movement of the soil. 

Poured Concrete Retaining Walls

Do you remember that fancy apartment complex you looked at with your roommate a while back? There is a huge office with a fancy-schmancy garden next to it with a wall keeping everything contained. That wall is another retaining wall. 

You’ll also find these types of retaining walls holding up large hillsides by residential homes. 

These walls are incredibly durable and have a lot of flex and strength. 

These use concrete cinder blocks reinforced with a concrete footing and weep holes for moisture to escape. 

These are probably the most common types of retaining walls you’ll see. They’ll have rebar on the inside and be filled in with concrete. 

So the parts: Cinder block, rebar, and concrete. Drainage should also be part of the build. 

Interlacing Concrete Block Retaining Walls

This retaining wall uses interlacing concrete blocks. This type of retaining wall doesn’t require mortar.

These walls are set by laying the first course of blocks that are placed to be level. The layers after that will be stacked on the first set, interlacing until set at the desired height. 

A drain pipe will be installed behind the wall and covered in gravel. That way moisture will quickly escape.

Gravity and moisture are a retaining wall’s enemy

That might be a little dramatic. The earth is just doing its thing while the wall says, “stop doing that thing, please.”

Regardless, the purpose of a retaining wall is to combat the lateral movement of the soil. And they did the job well. People wouldn’t have them if they couldn’t do the work.

However, a lack of proper drainage can hurt your retaining wall. Mounds of dirt and soil are already heavy enough. Gravity isn’t going to make a deal and cooperate with you. 

What happens when they soak in moisture? They get much, much heavier, forcing your retaining wall to work harder.

And much like when you’re overworked, you can burn out. The same goes for a retaining wall. 

Proper drainage is essential, whether from having weep holes or French drains by the base of the footing. You need to prevent hydrostatic pressure on your retaining wall. 

Retaining walls also need repair

Not all of them do, but those that are poorly constructed are more likely to need repairing.

Concrete generally has a shelf life of 100 years under its best conditions. Corrosive soils and water can break down the elements of the concrete. These will be your main culprits.

Not all retaining walls will break down the same. It depends on the conditions the retaining wall was maintained. Our project design specialists have looked at walls from the 1960s that were falling apart, whereas others built in the 1920s look like they’re almost as good as new.

Earthquakes are well known in Southern California to cause damage. There have been other instances – which we don’t wish upon anyone – where a car has crashed into a wall and damaged it. 

Signs of a failing retaining wall:

  • Leaning
    • Sometimes tree roots push on the wall, the footing is failing, or poor drainage will cause this. This will be hard to miss, especially when your wall is perpetually doing the Michael Jackson lean.
  • Sagging
    • You’ll see sagging if your footing fails in a specific spot. 
  • Cracking
    • Hairline cracks won’t be much of an issue. However, if the crack is more than a quarter of an inch and stretches across the wall, there may be structural damage.
    • General rule – If you can put a quarter in one of the cracks, have a professional come out and look at your retaining wall. 
  • Bulging – This is a sign of water pressure building up behind the wall.

Repairing retaining walls

We can put the wall back into place by fully excavating behind the wall, pushing it back, and holding it into place. This method is very difficult and expensive.

Another method Dalinghaus Construction uses is helical tiebacks depending on the type of retaining walls. We can install these in a poured concrete retaining wall, but not interlacing concrete blocks. It depends on the wall and the materials used. 

Helical tiebacks will be used on a leaning wall and provide great results. These tiebacks are hydraulically driven into competent soils to prevent further movement, stabilizing your wall from leaning any further. 

If the lean is too much, it’s sometimes easiest – and better for your wallet – to demo out the wall. 

Cost of repairing a retaining wall

Depending on the extent of the damage, the pricing can be at a wide range. It will also depend on the height of the retaining wall. 

Repairs can cost $300-$900 per linear foot

Cost factors to consider

  • Age of the wall.
    • Retaining walls generally last 50-90 years.
  • The amount of lean.
  • The size of the footing.
    • Some footings installed may not have been large enough to sustain the load.
  • Types of soil.
    • Remember what we talked about with soils soaking up moisture? Expansive soils will push out a retaining wall.
  • The type of hillside or slant.
    • How steep a hillside is can affect the amount of pressure being exerted on a retaining wall. 
  • Was the wall installed properly?
    • You’d be surprised by the number of contractors who don’t do the best installation or repair work. 

You want to read our article How Much Does a Retaining Wall Cost (New and Repaired) for an in-depth look at how the cost is determined.

You’ve retained a ton of information. Now schedule a free inspection of your retaining wall. 

You’ve learned about what retaining walls are, the different types, how they can be damaged, repairs that are done, and a brief overview of the cost. If you’re concerned about your retaining wall, have a professional come out and take a look. 

Have multiple companies look at your retaining wall so you have more than one opinion, compare costs, and determine which company is right for you. You want to be sure a company can retain your trust before you go forward with your repair.

Repairing retaining walls isn’t cheap. Not repairing one is more expensive. Have someone take a look.

Schedule a free retaining wall inspection with Dalinghaus Construction if you want a good start and an honest look at the damage you’re dealing with. 

Watch this video on how we look at retaining walls with one of our Project Design Specialists, Mark Cook.

If you’re not sure what you should do with your retaining wall, read our article Should I Fix, Replace, or Tear Down My Retaining Wall?

For any questions, call Dalinghaus Construction at (877)360-9277, or click the button below to schedule your free foundation evaluation today!

WRITTEN BY

Brian Dalinghaus

Brian is one of the Co-Founders of Dalinghaus Construction. He has been in the foundation repair industry since 2005. During his career, he has been associated with helping over 4,000 homes and structures throughout California and Arizona.

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