Things to Know When Waterproofing a Retaining Wall

Things to Know When Waterproofing a Retaining Wall

Waterproofing a retaining wall is arguably a critical process you should be aware of if you have a retaining wall. By doing so, you can protect your retaining wall from damage and repairs.

In this blog, we will answer share the things to know when waterproofing a retaining wall.

At PPC Concrete Products, we are here to provide solutions for your construction needs, from the person working on their part-time project to commercial clients, and everyone in between.

Monthly construction output had risen an estimated 1.6% value in June 2023, and we would like to think our accessible concrete products had a small part to play by giving our clients easy access to reliable and easy-to-use construction solutions.

Why does a retaining wall need waterproofing?

Why does a retaining wall need waterproofing?

Retaining walls require waterproofing as they are constantly having to deal with water. By failing to waterproof a retaining wall, and include adequate drainage, your retaining wall won’t last long. Additionally, it can even become a hazard to others if it falls.

Here are some of the many benefits your retaining wall can experience from having waterproofing.

  • The retaining wall will last longer as it is protected from water damage that can cause structural issues and mould growth.
  • Repair costs that come as a result of water damage can be avoided by waterproofing.
  • The aesthetics of the retaining wall are retained as they are safe from water stains and efflorescence, which is a light powdery deposit caused by water movement.
  • A damp environment is the perfect breeding ground for mould and damp. This can not only cause health problems to those exposed to it, but can contribute to the retaining wall material deteriorating further.
  • Depending on the location of your retaining wall, improper drainage can affect its surrounding areas, so if your retaining wall is by your home or another structure, you must ensure the drainage and waterproofing is used. Otherwise, you will be dealing with more avoidable headache.
  • Waterproofing will help to preserve the structural integrity of the retaining wall. Without waterproofing or adequate drainage, the retaining wall will suffer, this can come in the form of leaks, bulges, the wall bending, leaks in non-drain areas, and more.

Things to know when waterproofing a retaining wall

Things to know when waterproofing a retaining wall

Waterproofing a retaining wall is an extremely effective method in preventing any issues that can occur as a result of excess moisture that is not addressed. However, did you know that in some cases, waterproofing a retaining wall may not even help? Below, we will explain some things you need to know when waterproofing a retaining wall.

Waterproofing something weak won’t help

If your retaining wall is already weak or affected, waterproofing it will just be delaying the inevitable. If any of the following factors apply to your retaining wall, we would recommend fixing that issue first before seeking to waterproof it. You should not waterproof your retaining wall if it is already…

  • Extensively damaged and cracked and requires repair.
  • There is little to no drainage, or the current drainage system is not effective.
  • The wall is bulging or bending over.
  • Is built poorly using sub-par construction materials.
  • Lacks proper foundations.

What you use matters

Two popular options for waterproofing a retaining wall are damp proof courses (DPC) or using a liquid membrane. The former should be installed during the construction of the retaining wall, whilst the latter can be applied after construction.

Both can be used in conjunction with each other and can increase the level of waterproofing from both the inside and the outside of your retaining wall. Both options have the potential to last years, depending on the quality of the product and the current state of the retaining wall.

As long as the retaining wall does not sustain serious impacts, both options can last a number of years.

Drainage is the first step to waterproofing a retaining wall

Drainage is a key element for the general well-being of a retaining wall, in addition to the effectiveness of any waterproofing methods you apply. Drainage of a retaining wall must be appropriate to the size and depth of the retaining wall, simply having a pipe isn’t enough.

If your drainage is sub-par, you can expect your retaining wall to have puddles at the top, little to no water being drained, and structural issues such as the wall bending or bulging.

Is it easy to waterproof?

Consider the material you are going to use for your retaining wall. Although wood is a reliable and useable option in most cases, it is very susceptible to water in the first place. So it would make more sense to start with a material that is naturally more resistant, such as concrete blocks.

Using Interlocking Concrete Blocks for a retaining wall

Using Interlocking Concrete Blocks for a retaining wall

One of the most effective resources you can use when it comes to creating a retaining wall are Interlocking Concrete Blocks. These special pre-cast blocks do not require mortar in order to create a long-lasting and effective connection.

Interlocking Concrete Blocks connect to each other via studs and recesses at the top and bottom of the blocks, respectively. Individually, concrete blocks are heavy, but once they are joined, they provide an excellent counterweight against exceedingly heavy applications like a retaining wall.

Considering the fact they do not require mortar to connect, it is safe to say you will be saving money that would otherwise be spent on binding materials, and even some labour costs. But what actually makes Interlocking Concrete Blocks special? Well, a lot of things.

Here is a list of some of the uses that Interlocking Concrete Blocks can facilitate.

  • Material Storage bays
  • Blast walls
  • Salt stores
  • Crash protection
  • Push walls
  • Security barriers
  • Segregation bays, i.e. recycling centres
  • Retaining walls
  • Industrial buildings
  • Fire breaks
  • Counterweights
  • Roadblocks

What are the advantages of interlocking concrete blocks?

  • Longer lasting and more durable than a Gabion basket
  • Quicker and less hassle to install
  • No need for mortar, saving you money and time
  • No need for steel reinforcement or shuttering
  • Resistant to extreme weather conditions
  • Fire-resistant properties, mitigating the spread of fire depending on the structure
  • Little maintenance required
  • Often, no foundation is needed before installing
  • Sound resistant
  • Sustainable
  • Ability to stack them upon each other
  • Flexibility in sizes
  • Appropriate for temporary and/or permanent buildings
  • Unlikely to be displaced due to the interlocking function

Does an Interlocking Concrete Block need waterproofing?

If you are going to use it for retaining wall purposes, we would recommend waterproofing the blocks in order to get the most usage from the blocks. Because our blocks do not use mortar or any binding materials, it does stand to reason that they are not entirely airtight.

We strongly advise that you get in touch with us regarding your retaining wall, and based on the conversation, we would be able to advise the best waterproofing option you should take.

Enquire about retaining walls today

As an established supplier all over the UK, PPC Concrete Products is always happy to help, which is why we encourage you to get in touch with any questions you may have or have a look at our FAQ.

In this blog, we hope to have shown you the things to know when waterproofing a retaining wall, whilst also providing extra information in regard to construction solutions that we offer.

Take a read of our case studies to truly understand how we have provided solutions for business in the past with the use of our interlocking concrete blocks, and ultimately, how we can help you today.

Read our blog page for more insights into our passion, construction.


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Higginshaw Lane,




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Tel: 01706 655245


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