Stem wall

What is a Stem Wall Foundation

There are two types of concrete foundations: Stem wall and monolithic. In areas prone to earthquakes, flooding, and other events, a stem wall on the foundation is very popular. What is a stem wall foundation? The stem wall is a supporting wall that joins the foundation to the vertical walls of the structure that is on top of the foundation. The wall is helpful in sending the load of the structure to the footing and from there it is evenly distributed over a wider area. It is sturdier than the monolithic foundations.

We will take a look at why you need to know about stem walls on a concrete foundation, how the stem wall is made, pros and cons, advantages, and about monolithic slab, pros and cons, advantages, other maintenance, and when to contact a professional.

Why You Need to Know About Stem Wall Foundation

Stem wall foundation is one of the two types of foundations available for homes. Depending on where you live, the type of foundation used Is determined by the weather events in your area. Areas that are prone to earthquakes or other events will see this type of foundation, which is also known as a slab foundation. Stem wall is more expensive than monolithic (which is simpler), but it is needed in many places.

Here is a video about Stem Wall Foundation:

How Stem Wall Foundation is Made

A stem wall is made by pouring the concrete at ground level, then blocks form a wall up to the finished slab elevation.  It is short and the height of a crawlspace. This type of foundation is much more stable when fill dirt is required to achieve the final build elevation. Dowels connect the footing and the walls and extend at least 14 inches into the stem wall. This is necessary for when events like earthquakes happen. If the dowels weren’t there, the stem wall could slide off the foundation and cause a catastrophe.

This process takes a bit longer than the Monolithic Slab, but a more stable foundation will prevent other issues down the road. These other issues may be with trusses or wall construction. Fill dirt gets the home to the final evaluation level and makes it strong and secure.

Stem Wall Foundation and the Pros and Cons

Pros

A stem wall is made of masonry, cinder blocks, or concrete. However, the poured concrete is often chosen as it is said to be stronger and necessary in areas with stronger winds. It is a two-pour foundation because of a pour for footings and for the walls. A foundation sealer can help keep the moisture out.

Cons

Issues with moisture– water can seep in while building so adding a french drain around the perimeter of the yard to drain it is essential. Save yourself money and have this done while the home is under construction. Even though it may add about $2000 to the cost, it is worth it to do at the time of construction of the home. The downside to the poured concrete is it may require the inspector to come out a few times to check it.

Advantages of Stem Wall Foundation

  • Protect the house- the base is lifted up so it is protected from flooding
  • Access for plumbing, wiring, and other systems.
  • Building on a slope-stem wall foundation height can vary depending on the elevation
monolithic foundation

Monolithic Slab Pros and Cons

Pros

These are an alternative to the stem walls and often seen in some southern states. They are one pour of concrete, unlike the two pours of stem walls. Thus, they are less expensive to construct. These are also found on homes that don’t have crawl spaces. Then, this is one less area for a homeowner to worry about and maintain. In the northern states, this type of slab is also more in garages and barns that are separate from the home.

Cons

Sometimes monolithic walls don’t work well for even the warmer climates due to the ground not being compacted efficiently. Additionally, the builder can make sure the ground is compact, but even then that doesn’t always work.

Another issue in the southern states, especially Florida, is that the home needs to be built above the flood plain, but often there is cracking around the perimeter walls. If you have a home in Florida, you will want to check to see what kind of wall structure was used. Often, the stem wall will be the one that is chosen.

monolithic slab with tension

Advantages of Monolithic Slab

  • Slabs can be sturdy when steel and fiber mesh is added
  • They are constructed faster so less labor time
  • Post-tensioning can be added so it helps when the ground is clay soil, loose, or poor quality
  • Can be used on hard ground
  • Known to be stable
crack in stucco

Other Maintenance to Think About

If you have a detached garage and have drywall, check on a few things when you are looking to make sure your foundation is not cracking.

Drywall can hold a certain weight so make sure you don’t have anything too heavy in the garage. If your favorite snowboard is hanging, check that the nails are the correct ones to use.

Walk around the home and check the stucco on the outside for any cracking. Fix anything that is less than 1/8 inch. Anything bigger, you will need to call a professional.

When to Call a Professional

Call a professional if you find any issues in the foundation, problems with the french drain or have questions about things you see on the inside or outside of the garage or home. A professional can help with advice and often will help you find a good way to solve the problem.

Conclusion

Knowing about the different types of foundations is important if you are building a home. Luckily, the builder usually knows what type to use depending on the slope of the land, the type of dirt, and also the climate. However, it is important for you to know if the builder is using the right type so stay informed. Colorado Inspection Team can take a look at the type of foundation that was used when performing a home inspection in the Castle Rock and Front Range areas in Colorado.

Thank you to Momentum Home Inspections for supplying the featured image of this post.

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