Thursday, August 10, 2017
When my parents got their first home the backyard wasn’t fenced in, and being a young couple who’d just bought their first home, they decided to save money by building a fence themselves. It went up in the spring, and it worked great all through the summer and into the fall. One December morning my dad got up, let the dog out, and watched her cheerfully run over the fallen fence into the neighbor’s yard and then into the street beyond. It took a good part of the morning to bring her back inside. Obviously a fence that falls down isn’t the best fencing for dogs that jump, dig or run.
My dad, never the most diligent man at the best of times, had predictably taken shortcuts building the fence. Instead of bothering to check the frost line where we lived, he’d settled for burying the posts two feet deep and calling it a day. As the cold weather came, the moisture in the soil froze, causing it to expand and push the posts out of their holes (this is a process called frost heaving, or jacking). Deep into winter, a strong wind came up and the whole fence--along with its loose posts--went down. My father’s experience begs the question: what exactly is the best fencing for cold climates, and how should it be installed so that it stands up to tough winters?
Cold Climates Bring Challenges for Fences
The basic idea behind frost heaving is that, because water expands when it freezes, the water in soil exerts an upward thrust on things buried in it--like fence posts and deck footings--as it solidifies. There are different solutions to this issue, but the most common recommendation is to ensure your posts or footers go at least a couple feet beneath the frost line. You can call your local city permitting office to find out how deep that is in your area. Now, even if you dig that deep, some frost heaving may occur—especially with posts sunk in the ground—as the frost acts on the part of the post above the frost line. The surest solution is to pour concrete footers below the frost line that are wider at their base than at their top. This way, the expanding frost helps to lock them in place rather than work them loose. But the challenges that winter brings to your fencing don’t stop once you get above ground level. Winter can affect the fencing material you use, causing it to break down or become fragile.
Winter affects wood mainly because it changes the humidity content of the air (air tends to be much drier in winter than summer), causing wood to shrink. Periods of wet followed by periods of dry weather can also cause cycles of shrinking and expanding that will push fasteners like nails and screws out of the fence, and can cause boards and rails to come loose. Some materials, like vinyl fencing, are made of a material that doesn’t absorb water. Yet, as temperatures drop plastics enter a glassy state and become more brittle, making them prone to snapping upon sudden impacts (like slipping on frozen ground and trying to catch yourself on the fence). This makes PVC a less-than-perfect choice for fencing in a cold clime.
What Material Makes the Best Fencing for Cold Climates?
So what fencing material does do well in cold weather? From a purely structural standpoint, metals are the best material for cold weather fencing. The molecular structure of metals doesn’t absorb water, so they’re not as vulnerable to moisture-based swelling and shrinking. That’s not to say that water can’t work its way inside a metal fence, or that metal doesn’t contract. But water simply doesn’t saturate metals in the same way it does wood. There are a couple of fencing options that take advantage of this:
These fences are built to withstand many of the challenges of winter weather, at least structurally. Aesthetically, there may be other issues. While a wooden fence on metal posts can stay up through winter, its handsome youth will likely be short-lived. The wood fibers of the pickets are forced apart by repeated expansion and contraction throughout the winter, forming areas where mold and rot can take hold. On lower-quality metal fences, the protective coating may crack and flake off as the metal contracts and expands with the temperatures, leaving the bare metal vulnerable to rust.
Fences That Look Good Through More Than One Winter
Due to the issues that wood, vinyl, and aluminum fencing have in cold weather, steel is generally the choice that will stand up best to winter year after year. Steel does need more than a thin coat of paint to do that, though, and not all steel fences are created equal. There are several types of coatings that preserve steel from rusting away, and it is best to understand a little about them before you go looking for a steel fence:
All of these coating systems are aimed more at rustproofing than they are at appearances, which means that once these coatings are applied, your fencing will need to be coated with an aesthetically appealing coat. Now, it is possible to paint over any of these coatings with traditional paint, but this generally doesn’t work into the joints very well. Even with a primer coat, the odds are pretty good that the paint will still end up peeling off sooner or later. A better option is powder coating, which is applied as a layer of powder and then baked on to the metal. This forms a uniform layer that can vary in thickness as desired and tends to last quite a bit longer than traditional paint on most surfaces.
The long and short of all this is that the best fencing option for cold climates is e-coated steel that’s been powder coated. Without the heavy galvanization layer, the fence won’t end up with zinc coming through the paint, and the powder coat will stay smooth and beautiful no matter what. This combination, though, can be hard to find. Most fencing features only pre-galvanization to protect it from moisture, sometimes with a powder coating on top, through which moisture usually makes its way eventually. Almost no one uses e-coatings to really rust-proof a fence and keep it looking nice.
One of the few companies that do this is Fortress Building Products, with their line of thoughtfully and thoroughly engineered building products. Fortress orders pre-galvanized steel to make its fencing, adds a zinc precoat, and, once it is assembled, e-coats the fence panels before applying a layer of high-quality powder coat. These multiple coatings, and especially the unique e-coat, help ward off galvanic corrosion and corrosion due to atmospheric moisture, keeping their steel fence systems looking nice winter after winter even in the coldest climate.