How To Push Back A Retaining Wall

Retaining wall in backyard with plants above and below it

You may have noticed your retaining walls bulging.  Maybe you have had a stone or a block pop out of the wall.  Possibly it’s just a little out of alignment from how it was when it first was installed.  These can be worrying signs when your retaining wall is no longer winning the battle against the earth they are retaining.  So how do you fix it?  You may be wondering how to push back a retaining wall.

The answer to this question like almost all backyard questions is it depends on the specifics of your backyard. First, let’s start with what is actually going on with the retaining wall. Before you can solve a problem, you must diagnose the issue and the cause.

How To Avoid Pushing Back A Retaining Wall For Cosmetic Cap Stone Damage

If you live in a region where there is frost and the only part of the wall that is bulging is the top course or cap of the wall, you likely have some easy-to-fix frost damage.  We will explain what often happens throughout the course of the winter. The top layer of grass becomes saturated with water, freezes, and pushes against the top course of the wall, popping off the cap.  These cap stones can be removed and reset by a mason. Or, if they are loosely placed concrete blocks, you may want to use an outdoor rated adhesive to hold the blocks in place. 

This type of damage is primarily cosmetic, as there’s no damage to any part of the wall other than the cap.  To prevent the cap from coming off in the future, dig out the grass about 12-18” back from the top of the wall and install some 3/4” crushed washed stone behind the cap.  This will create a drainage area immediately behind the wall. It will also prevent that portion of the soil from becoming saturated and freezing.

How To Push Back A Retaining Wall For Serious Damage

Next, if you have a more serious bulge, midway down the wall, at the bottom, or the whole wall appears to be over topping, you can’t just patch the problem and move on. When your wall is no longer structurally sound, you must remove it and rebuild.  Depending on the height of the wall, you may need to get a structural engineer involved to design the rebuilt wall system.  If your wall is only 2-3’ high you usually don’t need a structural engineer, but it’s always a good idea to consult one anyhow.  Check with your city or town building department to confirm permitting requirements and engineering requirements for retaining wall repairs.

How To Push Back A Retaining Wall Step By Step

Generally, here’s exactly what you need to do if you have a failed retaining wall. You will have to to remove the wall completely. Then, you need to solve the problem that caused the failure in the first place.  Usually this entails removing fill from behind the wall and replacing it with crushed stone.  Often a wall will be built and backfilled with soil.  If that soil is not well draining (clay for example), the soil will hold water then expand when it freezes in the winter. 

Year after year of this freezing and expansion will eventually push the wall from its original position.  This can also occur without frost.  In some areas of the country there is expansive soils. This will expand and contract significantly from a wet to a dry state.  That repeating process can have the same or worse effects as frost on retaining walls, patios and structures in general.  

Can You Use The Same Material When Pushing A Retaining Wall Back?

If you find yourself needing to rebuild the retaining wall, sometimes you can reuse the blocks you are removing.  However, it’s not a bad time to consider using a new material. Unlike other backyard construction costs like pools, the material costs of a retaining wall are usually not the largest cost factor. The labor to build the wall is what takes the time and thus the budget allowance.  Structural natural stone is generally considered the most expensive route to go. Less expensive is poured concrete with a natural stone veneer. The most economical option is a precast concrete block system. 

How To Prevent Retaining Wall Damage

Whatever the wall system you choose to implement on your property, the most important part is to prevent the bulging from returning. This is done by using the proper backfill methods and preparation of the wall footing itself.  This can be designed by a structural engineer, and often it’s best to have the engineer visit your property after the wall has been removed. That way you can help determine the amount of material that should be excavated and replaced with drainage stone. Perhaps even the addition of drainage piping to eliminate water behind the wall.

Backyard showing the steps of how to  push back a retaining wall

How To Push Back A Retaining Wall Summary

Ultimately knowing how to push back a retaining wall consists of more than just pushing the wall back into place. You must do some removal and replacement work if you don’t want the bulge to come back in a year or two. However, don’t lose hope, it is possible to replace a failing retaining wall. You can prevent the problem from recurring by constructing the replacement wall correctly. With the right processes in place, you won’t have to think about how to push back a retaining wall again.