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Block Foundations 101

Block foundations are common the further north you go in the United States. Homeowners can benefit from understanding the pros and cons of these foundation types.

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If you live in western or northern Virginia, or Washington DC, chances are your home has a basement. Generally, basements are made from block foundations. These hardy foundations can support a ton of weight while utilizing a simple design.  

However, like all foundation types, block foundations come with their own set of strengths and weaknesses. In this article, we’ll inform you on how block foundations are made and some of the issues these types of foundations can run into.  

What is a Block Foundation?  

As the name suggests, block foundations are made of blocks that are stacked on top of each other and joined with mortar. An initial layer of masonry is built on foundation footings before the rest of the blocks are arranged. Not only does a block foundation support your home, but it also acts as a retaining wall – a barrier between the soil and your home. 

Most block foundations are constructed with concrete blocks, but some contractors may use compressed stabilized earth blocks that use materials such as limestone or sand mixed with concrete. Their high compression strength makes them just as strong as normal concrete blocks. No matter the material, all block foundations are constructed in a similar manner.  

Homeowners should also be aware that block foundations are NOT waterproof. Water leaks are always a possibility, especially in areas with high precipitation. In fact, this leads into the next important aspect in understanding block foundations. Let’s look at the biggest issues these kinds of foundations face.  

Hydrostatic Pressure   

Water is an enemy to foundations, and block walls are no exception. Since block foundations act as barriers against soil, anything that impacts the soil is likely to impact your basement as well. Hydrostatic pressure is the force most responsible for basement wall damage.  

Hydrostatic pressure is easy to understand. This is the phenomenon that you experience as you dive further below water – the pressure in your ears starts to grow and it feels as though the water is pushing a little harder all around you.  

The same thing happens when draining water builds up underground; when it rains or snows, the water seeps below the soil and it exerts more and more pressure the deeper it travels. Sometimes this water drains close to your basement and puts pressure on the walls. 

Standing water formations and high water tables can cause the same symptoms. If you live close to a lake or pond, be aware that these can also cause hydrostatic pressure to build around your home.  

Over time, hydrostatic pressure causes your foundation wall to bow outward or crack. Suddenly, your block foundation is damaged, and water begins leaking into your basement. Moisture can attract pests of all kinds and contribute to unhealthy mold growth. 


Another issue that block foundations often face is foundation settlement. Simply put, this is when a foundation is no longer supported by the soil below it. Water (or lack of it) also plays a major factor in this issue. There are three main reasons settlement occurs:  

  • Soil is too wet 
  • Soil is too dry 
  • Soil is not compacted tightly enough 

When soil becomes oversaturated by precipitation, it becomes soft and squishy. Your heavy concrete block foundation will sink into wet soil like your foot does when you step into mud.  

Even though drought is not a common occurrence in DC, Virginia, and surrounding areas, it can also cause soil to become unsupportive. Dry soil shrinks in size, becomes brittle, and cracks under the weight of your foundation.  

Lastly, poor compaction can cause soil to be weak. When soil particles are not packed tightly enough, small pockets of air cause structural integrity issues and your foundation once again sinks into the weak soil.  

No matter the cause of soil issues, your block foundation walls are always going to be too heavy for the weakened soil. Thankfully, JES Foundation Repair has plenty of options to combat the effects of foundation settlement.  

Protecting Your Block Foundation 

JES Foundation Repair has the tools necessary to keep your foundation walls protected no matter the cause of damage. We’ll outline the solutions we use for both hydrostatic pressure and settlement, so you know exactly what to expect when it comes to repairs.  

Basement Waterproofing 

Basement waterproofing includes a few different solutions that work in tandem to keep your basement dry and strong simultaneously. First, our team will install wall anchors to straighten out any bowing walls and protect them against building pressure in the future.  

Wall anchors are installed into unmoving soils away from your foundation so they offer permanent protection, and they also close any cracks that may be causing leaks. However, this doesn’t keep all the water out.  

Our team will also recommend using dehumidifiers, interior drainage systems, and sump pumps to keep water out and move any moisture away from the foundation. With these options working side by side, your basement is well defended against hydrostatic pressure.  

Pier Systems  

Since settlement is caused by weak soil, JES Foundation Repair uses pier systems that support your home and foundation without relying on the soil. Piers come in three varieties, each with its own unique design. However, they all accomplish the same goal – stabilizing your foundation. Our piers include: 

All our pier systems implement a similar basic design, with slight design differences depending on the style. However, all piers use a long, galvanized steel rod that is inserted below the ground into sturdy, load-bearing soils such as bedrock. These soils are unaffected by moisture-related issues. Plus, the piers push any uneven portions of your foundation back into place, restoring your home to its proper form and closing cracks in the process.  

An added bonus is that installation is minimally invasive to your property as the piers rest underground. Our team is dedicated to thoroughly cleaning up your yard after installation and taking care to keep your landscaping pristine.  

Dedication to Quality Service 

Since 1993, JES Foundation Repair has been helping homeowners keep their foundations in prime condition. If your basement walls are experiencing cracks, leaks, or any other damage, we can help.  

Our team of experts is ready to inspect your home and determine the best solution to the problem. Whether you’re currently dealing with foundation damage, or you want to protect against issues arising in the future, contact us today for a free estimate – we’re here to help.  

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