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Do Concrete Blocks Deteriorate?

Concrete blocks are a great way to create a sturdy foundation for your constructions. But do concrete blocks decay over time? We've researched the science, and here's what we've found out. 

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Concrete blocks are a classic element of many homes, but they can be susceptible to the damaging effects of moisture. They are porous, so moisture can easily seep through. Over time, this can lead to rot and deterioration, ultimately weakening the concrete block and the structure that it supports.

Concrete blocks have been a foundation of building for centuries. Keep reading to learn what to keep an eye out for and for tips on how to make sure your concrete blocks stay in top shape for years to come!

How To Make Concrete Blocks Waterproof

masonry worker make concrete wall by cement block and plaster at construction site, Do Concrete Blocks Deteriorate

If you live in a region where the humidity level is high and rain is a common occurrence, then it is best to waterproof your concrete blocks. The process of waterproofing is easy and does not require any special skills or tools. 

Materials needed:

  • Paint roller or sprayer
  • 1-gallon siloxane waterproofer
  • Masonry brush

Here are the steps on how to make your concrete blocks watertight:

Remove any dirt or debris from the concrete block's surface

When preparing the concrete for sealant application, you'll first want to brush and scrape away all of the dirt, grime, and other debris.

This will help the sealant adhere properly and will ensure that the sealant gets a good seal. Some surfaces can be cleaned well enough on their own, but others may require a cleaning agent and abrasive to get all the dirt and grime off.

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Sand the concrete block

Sanding the surface is a good way to get rid of the rough spots. It's not necessary, but it minimizes your chance of missing spots with the paint roller. An uneven surface will cause the paint roller from spreading out evenly, which will lead to uneven coverage.

As a result, you may have to use more sealant than necessary and do multiple coats to get an even coat. You can skip sanding though and use a sprayer instead of a paint roller so you can still get an even coat.

Apply the sealant to the block

A waterproofing sealant will go deep into the concrete and prevent water from penetrating the concrete block. Pour the sealant into a basin and use a paint roller to apply it. The sealant is ready to use and you don't need to mix it with water.

Always make sure the surface is dry before applying siloxane sealant. Use your judgment when deciding how much sealant to use. If you use too little, it won't cover the surface of the concrete blocks. If you use too much, it may look sloppy. 

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Wait for the sealant to cure

Most people tend to get impatient and apply the sealant without waiting. If you do this, it will not be effective and could actually create problems for you. The sealant doesn't do anything until it's cured. 

A siloxane waterproof sealant requires at least 2 weeks to cure. If you are planning to apply this kind of waterproofing sealant in a location where it will be exposed to rain or moisture, then you'll want to ensure that it is properly cured to achieve optimal results. You can cover and protect the surface while it's in the process of curing with a tarp.

Check out this siloxane waterproof sealant on Amazon.

How Long Do Concrete Blocks Last?

The longevity of concrete blocks depends on many factors, including the cement-aggregate ratio used, the exposure conditions, and the environment where the block is placed. In general, the average lifespan of a concrete block is 100 years.

Should I Worry If I See a Crack in Concrete Blocks?

Bricklayer worker installing brick masonry on exterior wall with trowel putty knife

Cracks in the walls of your home can be a sign of serious issues. When they occur, it's important that you take notice immediately even if you think that the crack is insignificant.

The reason why you should be concerned is that cracks can creep into and develop in walls that are structurally sound. Aside from that, the damage can grow over time and the problem can become so large that it could lead to the total collapse of your home.

In addition, the location of the cracks may also be a clue to what has happened. In fact, if the cracks are on the bottom of the wall, it may indicate that the wall has been compromised. This is usually due to the walls shifting and expanding due to the foundation settling. 

Other signs of structural damage to look out for

Another common sign of structural damage to walls is if you see any kind of bulge or indentation. This is where the wall has been weakened by whatever caused the damage. 

In addition, you should also be on the lookout when the walls of your home begin to lean against each other. It can be a sign that the foundation is not strong enough to support the weight of the structure.

If you find any of these signs in your home, contact a professional right away. They will be able to determine what has happened and what needs to be done to fix the problem. 

masonry worker make concrete wall by cement block and plaster at construction site

Common Causes Why Concrete Blocks Crack

Concrete block construction is one of the most cost-effective ways to build a home. It is a solid, sturdy, and long-lasting building material. Unfortunately, there are many different factors that can cause them to crack. These include the following:

Poorly mixed concrete

The mixing process is very important. If the proper ratio of ingredients is not observed, you will end up getting a substandard concrete block that will not have the necessary strength to hold up for a long period of time.

Incorrect curing

If a concrete block is not cured properly, it can break apart and crack easily. It is recommended that a concrete block be left to cure for at least 2 days.

Freeze-thaw cycle

Another common factor in concrete blocks cracking is the freezing and thawing that they are subjected to. This cycle usually happens after the winter season when the temperature elevates and thaws the concrete blocks.

The shift in temperature causes the concrete blocks to expand and contract. As this expansion and contraction occur, the concrete blocks experience internal stress and cracks begin to form over time. 

masonry worker make concrete wall by cement block and plaster at construction site

How To Prevent Concrete Blocks From Cracking

Control joints are intentional cracks designed to accommodate the natural movement of a concrete structure. It is an intentional break in the concrete block that allows for the contraction and expansion of the block freely without cracking.

As the temperature rises, concrete expands, and as it cools, it contracts. A control joint is achieved by cutting a groove into the concrete. The size and location of the control joints depend on the amount of shrinkage that the structure is predicted to undergo.

Control joints are usually sealed with a silicone sealant that will prevent water from seeping into the concrete. 

Check out this control joint silicone sealant on Amazon.

What Makes Concrete Blocks Better Than Bricks?

Concrete blocks are cost-effective. They are cheap compared to brick and other building materials. You won’t need to buy as many concrete blocks as you would bricks. They are also inexpensive to install. You won’t have to pay for mortar or other building supplies.

While it's true that clay bricks are far superior to concrete blocks in terms of quality, durability, and overall performance, there are times when your project doesn't need all of the extra features offered by bricks. 

What is the Best Concrete Block To Use?

Concrete blocks are made from either compacted crushed stone or fine gravel as aggregates. The aggregates are bonded with cement, while the sand serves as a filler and helps bind the aggregates together.

The best concrete block to use for any project is one that is mixed with fine gravel instead of compacted crushed stone. This type of aggregate will give you a stronger, denser, and more durable block.

Construction site. Building materials. Construction materials. Concrete block on wooden pallet. Red brick walls. Angular laying. Cement building blocks.

What are the Disadvantages of Concrete Blocks?

Concrete blocks are porous and absorb moisture from the environment. As time passes, the blocks can lose strength. With the help of moisture, they may crack and split apart, which is where the problem lies.

Depending on the source of the moisture, you may need to seal it off before it spreads any further. Other than this, there are no substantial disadvantages to using concrete blocks. 

In Closing

Concrete blocks will naturally start to show signs of deterioration over time. However, there are steps you can take to slow down this process and ensure they remain in the best condition for a long time. In order to achieve this, you need to apply a waterproof sealant to the concrete blocks. 

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