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What Are Block Foundation Walls?

White block foundation wall with crack.

For nearly 200 years, block foundation walls have been a popular choice to support buildings worldwide. There’s a reason for that—they’re strong and dependable structures.

Still, they aren’t invincible, and it’s important to understand what can cause damage to a block foundation wall (and how to fix it). On this page, we’ll cover everything you need to know about this foundation type.

Block Foundation Walls Explained 

Builders create block foundation walls using concrete or cinder blocks, a common construction method. They stack the blocks in a staggered pattern and join them with mortar, which provides strong support for the structure above. These walls are known for their durability and resistance to weather and termites. Both residential and commercial buildings frequently use block foundation walls.

History of Block Foundation Walls 

Concrete block walls have a long history. In fact, concrete itself can trace its roots back to even before the ancient Egyptians! It’s been part of human construction for millennia in some form or another.

According to the International Association of Certified Home Inspectors, American mechanical engineer William Ward completed the first reinforced concrete home in the U.S. in 1875. It still stands in Port Chester, New York.

Concrete blocks quickly became a popular home building material since they were much lighter than stone or brick blocks, and easier to transport. Nowadays, builders use these blocks to create foundation walls. Standard blocks are 16” x 8” x 8” and weigh about 40 pounds. 

Advantages of Block Foundation Walls 

Block wall in a basement.

Block foundation walls can support more weight than poured concrete walls due to their load-bearing capacity. When properly constructed, these walls are incredibly sturdy and can keep homes stable for decades.

They can be built quickly using a mortar mixer, shovels, trowels, and levels. Additionally, block foundation walls are an affordable option, making them ideal for homeowners on a tight budget.

Disadvantages of Block Foundation Walls 

Cracking block foundation wall.

Block foundation walls have some drawbacks. Without proper waterproofing, water can seep through the porous concrete blocks, increasing humidity in your and potentially causing mold growth. Additionally, if not built properly, block foundation walls can bow inward when under pressure, hurting your home’s structural integrity.

How to Protect a Block Foundation Wall

Protecting your block foundation wall is crucial to maintaining your home’s overall structural integrity. Here are some effective methods we recommend:

Basement Waterproofing

Man installing vapor barrier on a basement wall.

Basement waterproofing is essential to protect block foundation walls from water damage. This involves applying a vapor barrier to the interior walls to ensure water doesn’t seep through the wall. Proper drainage systems, like sump pumps and interior drains, are also a crucial part of basement waterproofing.

Wall Anchors

Wall anchor in a concrete wall.

Wall anchors provide support and prevent block foundation walls from bowing or leaning. They are installed by placing anchors in the soil outside and connecting them to steel rods that run through the wall. This system stabilizes the wall and prevents further movement.

Carbon Fiber Reinforcement

Man attaching concrete fiber to a block concrete wall.

Carbon fiber reinforcement is a strong, lightweight solution for strengthening block foundation walls. Carbon fiber strips are bonded to the wall with epoxy, providing additional support and preventing cracks from spreading. This method is non-intrusive and highly effective.

Steel I-Beams

Steel I-beams attached to a concrete block wall.

Builders use steel I-beams to reinforce block foundation walls and prevent them from bowing. They install the beams vertically along the wall and anchor them at both the top and bottom. Steel I-beams provide strong, long-lasting support, ensuring the wall remains stable under pressure.

Block Foundation Wall vs Poured Foundation Wall

Some people think block foundation walls and poured foundation walls are the same. While they both use concrete, they differ slightly in their construction and design. Here are the main differences:

Block Foundation Wall

Builders construct block foundation walls using concrete or cinder blocks, stacked in a staggered pattern and joined with mortar. These walls are known for their durability and resistance to weather and termites. They are also easier and faster to install, often used in both residential and commercial buildings.

Poured Foundation Wall

Poured foundation walls are made by pouring concrete into forms, creating a seamless, solid wall. These walls offer superior strength and resistance to water penetration compared to block walls. However, they require more time and labor to install, making them more expensive upfront.

Repair Your Block Foundation Wall With AFS

AFS crewman installing a vapor barrier onto a basement wall.

Now that you understand more about your block foundation wall, consider working with us if it has cracks or other damage. It’s important to address foundation damage as soon as possible. Waiting will only make the issues worse.

If you need foundation repair, contact AFS to schedule a free inspection today. We provide leading waterproofing and foundation repair solutions to homeowners in the Southeast United States! 

Block Foundation Wall FAQs

Yes, untreated foundation leaks can lead to structural damage, indoor air quality issues, pest infestations, and damage to personal property.

Usually, homeowner’s insurance does not cover issues arising from “settling, cracking, or shrinking” of the foundation. Exceptions may apply if the cracks were caused by a covered peril, such as a natural disaster. Always read your policy and consult your insurance agent for particulars. 

Even in dry climates, occasional rain or high humidity can cause moisture problems with porous walls.

Related Resources

Ted Dryce

Ted Dryce

Content Writer

Ted is an SEO Content Writer who has been with Groundworks since 2021. He’s covered home repair topics ranging from crawl space encapsulation to regional soil conditions. When he’s not working, Ted is performing improv comedy and working on his own creative projects.

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