Navigating Excavation in Northern Wisconsin: Unique Ground Conditions

Excavation is a critical first step in any construction project, laying the foundation—quite literally—for everything that follows. However, in Northern Wisconsin, the process requires a nuanced approach due to the region’s unique ground conditions. At KV Build, we have extensive experience dealing with these challenges, and we are excited to share our insights on how to navigate them effectively.

The Influence of Glacial Activity on Excavation Sites

One of the most distinctive features of Northern Wisconsin’s landscape is the impact of ancient glaciers around Lake Superior. A great glacial ridge cuts through the area, creating significant variances in soil composition over short distances. As a result, you might encounter clay, sand, rock, or a combination of these within a single excavation site. This variability can complicate excavation projects, requiring specialized techniques.

Let’s get into what you may see at any given excavation site in Northern Wisconsin, and how we account for the various terrain to ensure the stability and longevity of your structure.

Clay

Frost Protection and Drainage

One of the most common variances we see specifically in Northern Wisconsin is clay. Clay soils come with their own set of challenges—they don’t drain well and are prone to frost heaving. When working in clay-rich areas, it’s important to ensure proper drainage to prevent water build-up. This water build-up can cause the soil to expand and contract with freezing and thawing, affecting the stability of foundations and other structures.

To mitigate these risks, we do a few things differently:

• Drain Tile Installation: By installing drain tiles, we can redirect water away from the foundation, reducing the risk of frost heave and soil expansion.
• Free-Draining Backfill: Using clean, free-draining materials like sand for backfill helps prevent water build-up around the foundation walls, further protecting against frost-related issues.
• Placing Footings on Undisturbed Mineral Soil: It is important to place footings immediately following excavation in clay soils. If the soils are wetted with rainwater, it will cause the soil to expand and it will no longer be a suitable substrate for a foundation. Timing is very important! 

Structural Adjustments During Excavation

Since clay soils can put a lot of pressure on foundation walls, we use extra reinforcement techniques. Using sand for backfilling helps with drainage and reduces the pressure from the heavy clay, which helps keep basement walls and footings sturdy.

Sand

While sand presents fewer challenges than clay, it still requires careful consideration. Its high permeability means water drains quickly, reducing the risk of frost heave and soil movement. This makes sand an excellent material for backfill and foundational support. However, its loose nature sometimes requires compaction to ensure stability, especially for load-bearing structures.

Rock and Sandstone

Northern Wisconsin’s rocky terrain, including sandstone and granite shelves, provides excellent stability for construction. However, excavating through rock can be labor-intensive, often requiring specialized equipment such as hammer drills or jackhammers to achieve the desired depth. Despite the initial challenges, building on rock offers long-term benefits, including better structural stability and reduced risk of soil movement.

Starting Excavation in Northern Wisconsin

Excavation in Northern Wisconsin is far from a one-size-fits-all endeavor. Over here, successful excavation depends on understanding the varied soil conditions near Lake Superior. At KV Build, we adapt our methods to handle the unique challenges of the local terrain, ensuring each project is done with care and accuracy.

If you’re planning a construction project in Northern Wisconsin, contact KV Build today. Let our expert team guide you through the complexities of excavation and the not-so-standard soils, ensuring a strong foundation for years and years to come.