Why Does Winnipeg's Ground Shift so Much?

Winnipeg experiences very significant ground shifting. This majorly impacts landscaping work like patios, retaining walls and driveways. This phenomenon results from Winnipeg's soil composition and climate.

Summer Factors

Organic materials in the ground, like clay, absorb water and therefore expand. Given some time without rain, these same materials will dry out and shrink. Movement!

Clay soil is made of extremely tiny particles that pack together very tightly. Unlike sandy soil, which has large gaps that let water drain quickly, clay has very small pores between its particles.

Water can still enter these tiny spaces, but instead of flowing through quickly, it tends to cling to the surfaces of the clay particles. Because clay is made of countless microscopic particles, the soil has a huge total surface area for water to stick to. It can cling to the outside of all of these tiny particles.

That’s why clay-heavy soil doesn't drain the way sandy soils do. Instead, they absorb water and expand when wet.

Winter Factors

Winter introduces another set of challenges. Winnipeg's cold climate leads to a process called frost heave. When the ground freezes, soil moisture turns into ice, expanding and pushing the soil upward. Think about how when you fill your ice cube tray with water, once frozen the ice is larger than the liquid water was.

Water expanding as it freezes produces an incredibly strong force that can easily break very strong materials. It can crack rocks. It can split copper or steel pipes. So it has no problem lifting the concrete pavers on the surface of a patio.

Fall and Spring Factors

Thawing in spring reverses the frost heaving process, often leading to uneven ground settling.

In both fall and spring, you will have many days where the ground will thaw during the day and freeze at night.

Impact on Landscaping

As you can imagine, these ground movements have significant implications for landscaping. Structures like patios, fences, and even foundations can become misaligned or damaged. Understanding this natural process is crucial in choosing the right materials and construction techniques that can accommodate or mitigate the impact of these shifts.

Solutions for patios and driveways in Winnipeg

We are a landscaping contractor specializing in patio installation in Winnipeg. It's been our business to know how to deal with this for 28 years. Here's how we do it:

1. Minimize ground movement

If we excavate the clay soil immediately below the patio or walkway, we can allow water to flow through downwards, away from the bricks. We excavate the absorbant clay and then replace it with crushed rock which drains nicely.

But we will still have a lot of movement here in Winnipeg.

2. Build an extremely strong and rigid surface, or make the surface flexible

To deal with inevitable movement that will still happen despite excavation, we can either build an extremely strong monolithic pad enforced with rebar or we need to install a flexible interlocking brick system which can deal with movement.

At Earthworks Landscaping, we do flexible systems.

The basic principle is that brick surfaces allow for small movement in the joints between the bricks. This allows the whole patio, walkway or driveway to flex.

If you would like our help with patio installation, driveway construction or any landscaping in Winnipeg, we'd love to help. Get in touch for a very easy preliminary estimate.