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What Is A Raised Slab Foundation

By February 15, 2022Foundation
raised slab foundation

A raised slab foundation is very common in the Southeast region as the house is elevated above the ground to keep water from accessing the home after a rainstorm. This type of foundation also creates a more aesthetically pleasing look. What is a raised slab foundation? It is a cross between a raised foundation and a slab foundation on a grade.

Let’s take a look below at what concrete floors with crawl spaces consist of.

What Is Involved

The following is what happens when a raised slab foundation is created.

  1. Footings are dug and your foundation wall is created using concrete block.
  2. The concrete block outlines the layout of the home and is typically two levels of block.
  3. Crushed stone or fill dirt is then placed inside the surrounding wall and leveled.
  4. Moisture barriers are installed on top of the crushed stone or fill dirt.
  5. Wire mesh and plumbing and water lines are laid out on top of the crushed stone or fill dirt.
  6. A concrete slab is then poured over a wire mesh for stability and strength.
  7. Additional vapor barriers or flashing and sill plates are then installed for the exterior walls to be supported.
A type of foundation slab.

Types Of Slabs

Standard slab foundations consist of a six-inch thickness of poured concrete along with footings or columns. The footings are poured two feet into the ground and have a layer of rock, sand, or gravel added for drainage purposes. Footings can vary based on environmental demands for each state.

  • Raised slab foundations: typically a cross between having a slab and a crawl space. Perimeter walls are built with footings for support and the raised space is then filled with rock and soil for drainage. Then, a concrete layer is poured on top of the leveled materials. Found in high flood-prone areas like a coastline.
  • On-grade slab styles (monolithic): a basic layer of rock added to mesh wiring and footings for drainage. Then a slab is poured along with the footings to make it a single unit. This is mostly used in southern states that don’t experience freezing temperatures.
  • Floating slabs: mostly used for sheds and other structures that just need a concrete pad for support of the weight. It is not used for residential homes. 
  • Conventional foundations (T-shaped): heavy-duty reinforcements and footings are installed deeper than the line of freezing. These go past the homes perimeter and into your yard. Conventional foundations are commonly used in areas of the country that get frost and freezing temperatures. Also, stem walls are used to extend above the footings and a concrete block is used to separate the stem wall from the footings.

How Much Does It Cost

Needing a new raised slab foundation is not an easy repair. Depending on the size of the home you are looking at a price tag of $24,500 to $115,000 to elevate the home and replace the foundation. The majority of the cost is labor and materials. The average cost to raise your home runs between $3,000 and $9,000 and your excavation cost can range from $1,500 to $6,000.

Creating proper landscaping around the outside of the home is important. Additionally, you will want to consider what works best for the home. Usually, plants, shrubs, flowers, and mulch are a good idea. However, keep in mind that you don’t want to cover the foundation but you do want to keep the ground moist.

Another area to consider is keeping an eye on is the foundation. If you are noticing uneven flooring, your doors and windows are uneven and jammed or there are interior and exterior cracks in the walls, you may need to have your home looked at so it doesn’t collapse from foundation issues.

Tree growing next to a home and the roots will grow into the foundation.

Lastly, if you have a home that has a tree close by, check to make sure that the roots aren’t growing into the foundation. If they are, you can remove the tree, add a barrier, or trim the roots.

When Do I Call A Professional

Calling on a professional contractor or professional builder is key in this situation. No homeowner is going to elevate their own home and demo the old concrete slab in order to install a new concrete slab. Professional contractors or professional builders understand the state’s building codes and permit responsibilities for such a big project.

While you are looking into replacing your raised slab foundation, you can call on your local home inspection team. They can offer you the most reputable contractors list and provide feedback on other project needs.

Conclusion

Understanding what a raised slab foundation is necessary before proceeding to conduction research on replacement or repair options. Raised slab foundations keep the moisture out, can be resilient in harsh weather conditions, and are perfect for coastal properties.

If you have one of these foundations then you might want to contact your local home inspection team. They can provide you with a list of projects that might be needed at the same time you conduct a repair or replacement of your raised slab foundation. Call on Waypoint Inspection to conduct a home inspection in your home in Tampa and Central Florida.

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