Several geological and climatic factors put Orlando homes at risk of foundation damage. We’ll discuss each of these below and the role they play in hazardous ground movement and water damage.
Rapidly Draining Soil
Aside from Disney World, Florida is probably best-known for its beaches. Although Orlando is located inland, the soil under homes in the area – classified as Orlando series soil – is still sandy and silty. The ground is characterized by lightweight, loose particles that contribute to excessive drainage. Most Floridians are familiar with seawalls, a common structure designed to prevent such erosion near beaches.
Adequate ground drainage is typically beneficial when it comes to construction, but the loose dirt in Orlando is prone to erosion. As the runoff from precipitation moves quickly through the ground, it can carry the sand and silt particles with it, potentially leaving weaknesses under your home.
Your foundation relies on the surrounding soil for support and structure, so underground erosion can leave your home unsupported and open to settling. The erosion rarely occurs uniformly on your property, so differential settling frequently occurs and causes structural damage and instability.
Additionally, runoff can create voids around your concrete, allowing water to pool against your foundation walls for extended periods, especially during heavy rainfall. The longer water interacts with concrete, the more likely it is to soak through it or seep into foundation cracks, contributing to water damage and moisture build-up.
Above-Average Rainfall and Flooding
Floridians are accustomed to frequent and heavy rainfall, and Orlando specifically gets an average of 54 inches annually, nearly double the national average. Excessive rain is dangerous to foundations in any area, but it makes the risk of soil erosion even worse in Orange County.
Heavy and frequent rainfall more readily wash away portions of the ground under your home, contributing to differential settling. It also means that any voids created by erosion against your concrete are more likely to fill with water and leave your home open to water damage and high humidity.
Along with excessive rainfall comes a risk of flooding, and Orlando experiences flooding at a high rate. Floods leave properties at higher risk of water damage and differential settling as the soil erodes more quickly.
Hurricanes and Tropical Storms
Normal rainfall is often enough to create problems with ground erosion around homes in Orlando, but the city also experiences very intense rains during the six-month hurricane season from June to November.
Hurricanes and tropical storms can bring in excess of 15 inches of rain in a single day. Of course, this creates all of the foundation problems that typical rainfall brings but with significantly higher risk.
The dirt in the Orlando area is also characterized as highly acidic. Acids in the soil from rainwater, decomposing organic matter, and dissolving limestone bedrock can weaken your concrete over time. Acidic soil can cause foundations to crumble and lose their structural integrity, sometimes resulting in foundation failure and total structural collapse in extreme cases.
Lastly, much of Orlando is situated above limestone bedrock. Limestone is a rigid and reliable bedrock to support construction in many areas, but it dissolves when exposed to water and is highly prone to erosion.
Your foundation relies on the soil underneath for support, which in turn depends on the bedrock below. Over time, groundwater and runoff erode the bedrock, causing instability in the ground above and consequently in your home’s foundation. The excessive rainfall and rapid drainage in Orlando leave the limestone bedrock at a very high risk of erosion.
This damage to the bedrock creates underground caverns, a phenomenon known as karst that is prevalent in Orlando. Instability in the soil can contribute to differential settling and the eventual loss of structural integrity in your foundation.