If you’ve ever had a fence professionally installed in Winnipeg, there’s a good chance the installer set the posts in concrete. It’s a common method — concrete seems like it would hold posts firmly in place. But in Manitoba’s climate, concrete is actually one of the worst things you can put around a fence post.
Here’s why we don’t use it — and what we do instead.
Concrete is porous. It absorbs moisture from the surrounding soil and holds it against the post. In Winnipeg, where we see significant freeze-thaw activity through the shoulder seasons, this causes two distinct problems.
First, the concrete itself freezes and expands. As water in the concrete turns to ice, it expands approximately 9% in volume. This expansion exerts upward pressure on the footing — a process called frost heave. Over several freeze-thaw cycles, that pressure can physically push the post upward, causing it to rise out of the ground, lean, or shift out of plumb.
Second, the concrete traps moisture against the post. For wood posts, this accelerates rot at the base — the most common failure point for traditional wood-post fences. Even galvanized steel posts can corrode faster when moisture is held in constant contact with the metal below grade.
We strive to keep a simple promise: Use quality materials. Build carefully. Be responsive before, during, and after the work.
We drive posts using a post-pounder — a mechanical driver that drives the post directly into the soil to the required depth (approximately 3.5 feet, below Manitoba’s frost line) without displacing soil around the post the way a dug hole does.
The result is a post that stays plumb, stays at grade, and doesn’t require re-setting after a few hard winters.
There are specific situations where concrete footings are appropriate — large gate posts carrying significant weight, or posts in very loose or sandy soil where driven posts won’t achieve the required bearing capacity. In those cases, we’ll discuss the approach with you during your estimate. But for standard residential fencing in Winnipeg’s clay-heavy soil, driven posts without concrete consistently outperform concrete-set posts over time.
A fence built with properly driven posts below the frost line should remain plumb and at grade for the life of the fence materials — without the heaving and leaning you see with concrete-set fences after a decade of Manitoba winters. It’s one of the most important decisions in a fence installation, and one we take seriously on every project.