Leaking Concrete / Cinder Block Walls -Causes,Repair & Waterproofing

When it comes to livable spaces that are free of water seepage, cracks, humidity, or mold and mildew, there are some red flags to keep in mind. 

Walls are often constructed using Cinder blocks, and sometimes water can seep through them via cracked mortar joints or through the porous block itself.

Once water seeps in, moisture-related issues appear, which result in the deterioration of the surface.

Taking measures to avoid the consequences of water seeping through cinder block walls may be as simple as following a few simple steps such as:

  • Using a dehumidifier to monitor humidity levels,
  • Avoiding growing plants indoors,
  • Reducing congestion in the basement
  • Not storing any wood in the basement for instance.

These few techniques may come in handy once or twice, but they do not quite solve the underlying issue that resides in the foundation of the house.

Once water seeps through cinder block walls, there is a risk that the exterior damp-proofing membranes deteriorate with time too – meaning that the cinder blocks will quickly weaken due to water pressure from elements like rain.

How To Tell If Your Block Basement Walls Or Foundations Are Leaking

1.Visible Water Stains

This is one of the very first warning signs that your basement wall or foundation might be leaking.

If you notice even the smallest of a water puddle or stain following heavy rainfall, water flowing indoors, etc. then this may be your cue to contact a water damage restoration company as they are professionally equipped to solve this.

Attempting to turn this major issue into a DIY project may deteriorate your basement wall or foundation even more.

2.Stuffy Smell

You know that smell when you walk into an old or ancient building?

That’s the smell of humidity lingering long enough inside a space – indicating potential problems like mold and mildew, which is a whole other beast to fight.

This moisture creates a stuffy smell, which is another sign that your basement wall or foundation may be seeping water.

3.Mold And Mildew

Another common sign of a water leakage may be the nasty site of mold and mildew, which is a dangerous threat to your health.

If mold is identified inside your living space, call a professional who is able to confirm the presence of mold and who can fix the underlying issue. 


This is a white coating that appears on the surface of a wall, which is the result of water leakage, causing the deposit of salt.

While not as harmful as the presence of mold and mildew, it is another warning sign that your basement wall or foundation may be leaking.

Issues Leaking Block Walls Can Cause  

Perhaps two of the major issues that result from water damage are: mold and mildew formation, and structural damage to the basement wall or foundation of the house.

These are enough to consequently degrade the value of your home. So, hiring a professional who is best suited to treat such issues sooner than later is really important.

Health Risks From The Formation Of Mold And Mildew

Not only does mold smell nasty, but it poses a major health risk to those exposed to it.

Some mold can release mycotoxins, which some research suggests have serious health consequences to those living in contaminated spaces – these include: aches and pains, mood swings, headaches, issues remembering things, as well as nosebleeds.

Additionally, those with allergies are more sensitive to mold than others, leading to issues like: consistent runny nose, red eyes, a dry cough, skin rashes, wheezing, etc. 

What’s worse, is that those with severe mold allergies often face worse symptoms that may lead to shortness of breath – and this is especially common in those with pre-existing lung complications.

Mold can become an especially prominent issue for children, who if exposed to mold at an early age, face an increased risk of developing asthma by age 7 – according to a 2012 study that examined 289 homes and 36 different types of mold.

Again, treating mold and mildew through hiring a professional water damage company is your only safe bet when it comes to treating your home.

Structural Damage To Basement Walls Or The Foundation

Apart from the serious health risks caused by mold, your house itself becomes at risk of deteriorating both structurally and from a value-perspective.

Mold frequently grows on organic materials like wood, concrete, drywall, and wallpaper, and is more common to grow in bathrooms, basements, and attics.

With time, the formation of mold can easily eat such materials, reaching to areas like carpeting and insulation and eventually damaging the inside of the walls and the structure of your house. 

Water Damage from Leaking Walls?

Call 844-994-1288 for a Risk Free estimate from a Licensed Water Damage Restoration Specialist in your area.

We Can Help Find the Cause of the Leak, Stop it & Repair any Water Damage Caused.

Fixing A Leaking Cinder Block Or Concrete Block Wall 

 Firstly, there is only so much a homeowner can do to help mitigate these issues before calling a professional – otherwise they risk the same water leakage problems over and over again. 

Below are some actions you may consider taking to help fix a leaking cinder block or concrete block wall:

1.Determine The Source Of The Water Leakage

This is an easy one because cinder or concrete blocks are porous, and you can likely notice any areas where water is entering the wall.

You’ll want to specifically keep an eye on window corners, mortar joints, or areas around any piping where water enters/exits.

After you’ve pinpointed exactly where the leakage is coming from, one DIY thing you can easily do is to fill the cracks with hydraulic cement, which you can find in stores like Home Depot. 

2.Apply A Masonry Waterproof Product To Uncovered Interior Basement Walls

This is another attempt you can make at trying to fix a leaking cinder block or concrete block wall. Here, you can purchase a sealant, which is basically a waterproof paint found in places like Home Depot.

This already comes premixed, so painting it over the uncovered basement wall shouldn’t be a hassle. Be sure to generously coat the wall so as to make sure that all the surface holes are well-covered – allow it to dry and then paint another coat.

The good thing about this sealant is that once it is dry it forms a watertight bond that can prevent moisture from further seeping through.

3.Inspect And Repair Guttering And Downspouts If Needed

Another step you can take towards potentially fixing a leak is to simply inspect and repair guttering and downspouts – ensuring that the water is directed away from your house and not into it. 

Waterproofing To Prevent Leaks In Concrete Or Cinder Block Walls And Foundations 

We’ve covered some easy fixes when it comes to trying to stop any water leakage into cinder block or concrete block walls.

However, waterproofing techniques are your best bet to effectively fix the issue. This involves exterior basement waterproofing, interior basement waterproofing, as well as interior and exterior drainage.

Exterior Basement Waterproofing

This method is the best for stopping water from leaking into your basement from the outside, where you can incorporate the following steps:

  • Dig a drainage ditch: if you commonly have a wet yard, this method is highly advisable to help protect your house and avoid a wet basement in the future.
  • Place rain gutters far from your foundation: if your house’s rain gutters are located too close to any exterior walls on the property, try purchasing an extension which can help push the water away from your house – if possible. 
  • Examine the landscaping around your property: if you notice that it is slightly tilted away from the foundation of your house, perhaps try digging a little bit to help water flow away from your house rather than towards it.

Interior Basement Waterproofing

Waterproofing the interior basement involves the below key methods:

  • Installing a Sump Pump or Diagnosing a Water Leakage Issue from a Sump Pump

The presence of a sump pump is one of the most important elements of your house when it comes to managing water flow into your basement.

So be sure to have a professional install one if you do not already have it in your basement, or if you do have one make sure that it is working effectively.

  • Installing a French Drain

French drains are installed to help collect and divert rainwater away from homes. To learn more about french drains and how to dig and install one, click here

Interior And Exterior Drainage

Over a period of time, houses settle and this can lead to cracks in your foundation – so hiring a professional to deal with interior or exterior drainage is key.

As noted above, there are some exterior fixes to water leakage, and some interior ones. 

Carefully diagnosing the issue and assessing the situation prior to taking any action steps is very important.

While some fixes may appear easy and can call for a DIY project, others are big and may best need professional solutions.

When To Call A Professional 

If you have tried an easy fix but can still see, smell, or feel moisture-related issues surfacing again in your house – now may be a good time to seek professional help.

In addition, if your house is an older build, we suggest you call someone who is better equipped to manage any water damage to your house.

At the end of the day, you want to maintain the value of your property – and sometimes going the cheaper route may end up costing you in the long term!

We have Water Damage Restoration Technicians that can help Find the Source of the Leak, Repair any Damage & Prevent your Block walls/foundations from Leaking again.

For Disasters of all Sizes,available in 95% of the USA

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