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Block Foundation Walls

Block foundation walls that are built the right way and reinforced can be extremely strong and durable.

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So much goes into building a foundation that homeowners often don’t consider how their foundation walls are going to be built. If you go with a block foundation wall, it’s important to know whether it’s going to serve you well and the potential issues that can arise. Let’s delve into these details. 

What Are Block Foundation Walls? 

Block foundation walls refer to walls that are made from hollow concrete blocks. During construction, builders lay the blocks on top of the foundation footing and join them with mortar. Each row of blocks forms a course until the wall rises to the desired floor height. Rebar is then used to strengthen the walls. 

The width and thickness of the foundation wall footings depend on the block size in use. When erecting the walls, the builders must ensure the footing is as thick as the blocks are wide. And the footing has to be three times as wide as the concrete blocks. 

History of Block Walls 

A step up from brick walls and stabilized earth block walls, concrete block walls have been in use for several decades. The first house with block foundation walls in the country was built around the late 1830s in Staten Island, NY. A few years later, the first patent for hollow concrete blocks was issued to Harmon S. Palmer. 

Right about that time, locals started using sand-gravel aggregate blocks. These materials were both lightweight and easier to store than traditional bricks. Today, builders around the country use concrete blocks to erect foundation walls and basements, with the standard blocks weighing roughly 40 pounds. 

How Good Are Block Foundation Walls? 

When building with concrete blocks, wooden forms aren’t required. The contractor only pieces together and secures forms for concrete pouring. The blocks are usually light in weight and easy to install. These blocks are also strong, and in most cases, well insulated. Their versatility makes them suitable for construction in areas with active seismic activity. 

The main problem with block foundation walls is that they are susceptible to water, especially if they’re built on shifting soils. Water can weaken and wear away the mortar holding the blocks. After some time, water will start seeping through the joints’ exterior. If the water gets trapped inside the walls, it will push out and cause the walls to bow. 

Should Block Foundation Walls Be Reinforced? 

Yes, block walls need reinforcement. This is done after the blocks have been laid. Reinforcing them involves filling their voids with poured mortar or poured concrete. If there are narrow voids, your builder may use concrete with small gravel. One-and-a-half-inch steel rods are also used to strengthen these walls. 

Waterproofing Your Foundation 

Water remains a threat to your block foundation wall, damaging its health and reducing its service life. To avoid water damage, ask your local foundation contractor to waterproof the block walls. What this does is cut off underground water or moisture from seeping through the walls and infiltrating your basement. 

If your walls have cracks or gaps, they must be sealed first before waterproofing commences. The same goes for leaning or bowing walls, which have to be stabilized and straightened. The reason for this is that small cracks can widen and allow more water to enter the basement while bowing walls can collapse as water pushes against it. 

While your home is in construction, your building contractor will apply a waterproofing membrane to your wall. Also, they will install drain tiles to collect and channel excess water away from your home. Once they install the tiles, they will backfill the trench with gravel and topsoil. If you are retrofitting your basement with waterproofing, the contractor will perform minor excavation to your basement floor, place a specially designed interior drainage system in the trench and connect it to a sump pump system, and then replace the cement. 

Would you like to repair or seal your leaky foundation walls? Get in touch with the experts at Foundation Recovery Systems for a free inspection and quote. We will tell you what’s ailing your foundation wall and recommend the best fix to the problem so water won’t bother you again.