Why Do Pavers Sink?

It’s a terrible feeling. Your beloved pavers, looking so perfect from day one, have sunken and are a complete eyesore now. If you’re lucky, you may have gotten a few years use before this happened. And if you’re not so lucky, it may have happened to you within a few days of installation.

Don’t fret! Sunken pavers are not uncommon. After all, you’re dealing with Mother Nature, and Mother Nature will do what she wants to do to your pavers. The key to fixing sunken pavers is to understand why it happens, and therefore ways you can prevent it from happening.

Why Your Pavers Sink

Let’s begin by looking at the reasons why pavers sink.

Way Off Base

One of the most common culprits of sunken pavers is the base. This could be due to poor preparation, meaning the gravel wasn’t compacted properly, or the base isn’t deep enough, or you used too little or too much sand.

Sometimes, despite all your best efforts in preparing the base, the ground may still settle to a certain degree, causing your pavers to sink. This usually happens within the first five years of installation.

Do you live in an area with cold winters? The freeze-thaw cycle will most definitely move the ground below your pavers and potentially cause them to sink.

Troubled Waters

Water can erode the rocks and soil below your pavers and as a result, you get sunken pavers. This can be a problem for those who have their pavers too close to a water source, such as a gutter downspout.

Improper drainage will also cause your pavers to sink. When excess water has nowhere to go, it can cause not only your pavers to sink, but extensive damage to your basement and foundation of the house.

The Root Cause

Trees are wonderful. They give off oxygen and provide shade. Plus, if you sit underneath them long enough, they may even lead you to some scientific discovery. But they may be the very thing that causes your pavers to shift.

The roots of your trees and bushes may still be growing and sometimes, their roots may grow too high, digging right up to your pavers and causing them to be “wavy”. This is usually a problem for people who have trees and bushes near their pavers.

How Do I Stop My Pavers From Sinking?

Once you understand why your pavers sink, you can take steps to stop them from sinking. Smaller problems will usually involve quick and easy fixes that you can do yourself. But larger issues will require more complicated work best done by a professional.

How to Fix Sunken Pavers

If the problem is the base, first look at the extent of your problem. If only a small area is sinking, chances are your base is still largely intact, and you can simply redo the problematic area.

To repair the base, add more gravel and compact. Then add more sand and level. If only the layer of sand has shifted, and it doesn’t look like you have to fix the bottom gravel layer, simply add more sand and level.

Quikrete Paver Base
Fix your sunken pavers with some extra sand.

Unfortunately, a larger base issue may require redoing the whole project. If a large area is sinking, the best thing to do is to excavate the whole area and start from square one. See our instructions in the next section on how to properly prepare your base.

If the problem is water, you have to install proper drainage. This can be a large task, so you may want to leave it to the pros. But the idea is to divert excess water to a collection point – either an open area on your property or, with permission from your local authorities, a street gutter.

Water from a gutter downspout can be diverted by extending it to an open area. It’s a small enough job that you can do yourself. Once you get rid of your water problem, it will no longer cause your pavers to sink.

Flex-A-Spout Downspout Extension
Divert water from a downspout using an extension.

If the problem is root growth, you can attempt to fix the problem by removing some roots. However, you risk harming the tree by removing large roots or removing too many roots. It wouldn’t be a bad idea to call an arborist for advice.

You may have to face the difficult decision of removing the tree or bush altogether. Or you may consider moving your pavers to another area!

The Perfect Base

As we mentioned earlier, you need to prepare your base properly if you don’t want your pavers to sink.

What does that mean? It means your base should be deep. How deep? You should dig 12” deep. This will allow you to create a layer of compacted gravel that’s 10” deep for maximum stability. If you can’t go that deep, make sure you have at least 6” of gravel. Your gravel must be compacted incrementally as you go up. You need it to be tight. To finish off, you should lay 1” of sand – no more, no less.

If you do your base following these instructions, you will give your pavers the best chance at staying afloat!

Sinking Into Despair

Base good? Check. Water draining well? Check. Roots not an issue? Check. You’ve addressed all the potential causes but for some reason, your pavers are still sinking!

It’s hard to say what the issue is without examining the area first-hand. If you’ve addressed all the issues we pointed out, it should have fixed your problem. But if not, it may be time to call up your local landscaper for a close examination.

Have Fun Out There!