Aluminum Fence Systems
Aluminum Fence Systems
The blog cover image is for reference purposes only and does not depict the actual Medallion Fence product.
Drive through an industrial park in Brampton, Laval or south Edmonton in late February and you will see the same thing over and over. A sharp 2.4 metre steel picket fence, properly galvanized, nicely powder coated, with a plow windrow piled halfway up its face. On the drawings it was a security fence. On site it has become a short step with a handrail.
That gap between the drawing and the real site is where most perimeter specs fail. This post covers the decisions that decide whether a steel fence actually deters someone: height, picket spacing, rail layout, top treatment, sightlines and gates. It also covers the Canadian problems that American spec sheets never mention.
Start with honest expectations. ASTM F2781 is the practice used to rate forced entry delay on security fences. It says outright that no fence can fully resist a determined, well-equipped attack group, and that entry is defeated by adding time and by detecting the attempt early. A fence buys minutes. It does not buy certainty. If your client expects the fence alone to stop break-ins, correct that in the design brief, not after the first incident.
CPTED gives the fence a broader job. It marks territory, so everyone knows where public space ends. It preserves natural surveillance, so staff, passersby and cameras can see through it. And it controls access by pushing people toward a few gates you can actually watch. A solid wall handles the first job only. An open steel picket system can handle all three, which is why it remains the default on frontages where the architect also cares how the building meets the street.
ASTM F2814, the guide for ornamental steel picket fences used for security, names the main levers: greater height, picket styles that curve outward to form a parapet on the attack side, and tighter spacing between pickets. Everything below builds on those three, plus two things the guide cannot account for: our winters and our bylaws.
Do not pick a height and then check the bylaw. Do it the other way around. Toronto's Chapter 447 is a good example of how specific these rules get. For non-residential property, a fence in a front yard within 2.4 metres of a lot line abutting a public highway is capped at 1.2 metres, while "any other fence" may reach 2.5 metres, with height measured from average grade one metre away on either side.
That creates two practical problems. First, a 2.4 metre panel set 50 mm above grade, with spear points rising above the top rail, can easily measure over 2.5 metres. Detail the overall height on your drawings, not the panel height. Second, snow is not grade. The bylaw measures from the soil. The intruder measures from the top of the snowbank.
Our working recommendation: 2.4 metres overall as the baseline for side and rear lines on industrial sites where the bylaw allows it. A 1.8 metre fence deters opportunists and little else. Then show a dedicated snow storage area on the site plan, well clear of the fence line, and write it into the owner's snow removal contract. Where plows have no choice but to push toward the fence, a concrete curb or bollards in front of the line stops both the windrow ramp and blade damage to posts.
People obsess over the air space between pickets. A climber does not need to fit through the gap. They need a grip and a foothold, and a cutter needs as few cuts as possible.
A typical commercial layout uses 25 mm square pickets on roughly 100 mm centres, which leaves about 75 mm of air space. That stops a body from passing through. Tighter spacing earns its cost in delay: to open a crawl hole about 400 mm wide, every extra picket in that width means two more saw cuts. For higher risk lines, F2814 also lists supplemental fill such as welded wire mesh or expanded metal fixed to the fence.
Rails are the real climbing aid. Every horizontal member on the attack side is a step. Specify rails on the secure side so the outside face reads as an unbroken field of verticals. Avoid flush top panels where the top rail caps the pickets. That gives an intruder a clean handhold at exactly the height they need it.
At the bottom, keep the clearance to roughly 50 mm. Frost heave and settlement will try to open that gap over a few winters, and loose soil invites digging. A continuous concrete mow strip under the fence line solves both problems. On sloped sites, specify rackable panels that follow grade rather than stepped panels, since stepping leaves a triangular gap under every step.
Here is something rarely discussed in spec meetings. A picket fence that looks open when viewed head on can look solid from an angle.
For square pickets, the open fraction at a viewing angle measured from perpendicular works out to: 1 minus (picket width divided by spacing) minus (picket depth divided by spacing) times tan(angle).
With 25 mm pickets on 100 mm centres:
Head on: 75 percent open
At 45 degrees: 50 percent open
At 60 degrees: about 32 percent open
Past about 72 degrees: fully opaque
So a camera mounted on a building corner looking down the fence line sees a steel wall, and so does a guard driving parallel to it. Position cameras to view the fence at 45 degrees or less from perpendicular, or put them inside looking straight out across the clear zone. Thinner pickets or wider centres improve transparency but reduce delay. That trade-off belongs in the design brief, not in a supplier's substitution request.
Keep a clear zone on both sides of the fence. Thunder Bay's CPTED guide, like most Canadian municipal guides, recommends keeping landscape shrubs no higher than 36 inches. Just as important: no trees, pallets, dumpsters or light poles hugging the fence. Each one is a ladder somebody else paid for.
From least to most effective:
The rail caps the pickets. This is a handhold. Avoid it on any security line.
The pickets rise above the top rail. This is a big improvement and the most common commercial choice.
The pickets bend toward the attack side and form a parapet. A climber has to work outward and upward against it, which is exactly what F2814 recommends.
Rotating spike rollers, barbed tape and similar products, where they are legal.
That last point matters in Canada more than most people think. Toronto prohibits barbed or sharp material in fences, with a limited allowance for material mounted at a height of not less than 2.5 metres on metal brackets. In one 2025 encroachment approval, Toronto's community council attached a condition that no spikes or pointed tops were permitted on the fence, gate or pillars. Not every city treats spear points as "sharp material," but before tender, ask your municipality in writing.
Owners always ask about liability. In Ontario, the Occupiers' Liability Act narrows the duty owed to people who assume the risk to not creating a danger with deliberate intent to harm and not acting with reckless disregard of their presence, and anyone on the premises to commit a crime is deemed to have willingly assumed all risks. That supports visible deterrent toppers. A hidden or disproportionate hazard invites argument. Other provinces have their own statutes, and this is not legal advice. The practical answer is usually a visible, outward curved top rather than the sharpest product in the catalogue.
Most fences are breached at the gate. Specify these points:
The gate matches the fence height and top treatment. No lower "convenience" leaf.
Gate frame horizontals face the secure side, and the infill matches the fence spacing.
Gaps at the latch post and under the leaf are no larger than the fence's bottom clearance.
Hinge pins are capped or welded so the leaf cannot be lifted off.
The latch has a shrouded keeper so it cannot be shimmed.
For vehicles in snow country, cantilever slide gates beat track gates. They have no ground track to fill with ice, snow or gravel, but need rack space of roughly 1.5 times the opening width behind the leading post. Show that space on the site plan early. It takes landscape and parking with it.
For automated gates, note that CSA C22.2 No. 247 has been withdrawn and replaced by ANSI/CAN/UL 325. Gate construction should follow ASTM F2200, as operator manufacturers specify. On retrofits, check what the existing operator is actually certified to.
Finally, apply CPTED to gate count and placement. Use the fewest gates the operation allows, and put them where office windows, lighting and cameras already look.
ASTM F2408 is a sensible baseline. It requires hot-dip galvanized steel with polyester or epoxy and polyester powder coatings, plus testing for adhesion, corrosion, impact and weathering resistance. One thing to watch: older Canadian specs often cite CSA G164 for galvanizing. Its scope covers articles intended or primarily for use in electrical and communication systems, so ASTM A123 is usually the cleaner reference for fabricated fence parts. Within splash range of salted roads, specify a duplex system (galvanizing plus powder) and zinc-rich touch-up on every field cut. Have an engineer size posts and footings for local frost depth and wind load, with heavier posts at gates.
Usually no. The bylaw cap arrives fast. Control where the snow goes instead, and protect the fence line with curbs.
On its own it is marketing language. Ask for test evidence such as an ASTM F2781 delay rating, or at least the geometry: rail position, spacing and top detail.
Maybe. Ask the municipality in writing before tender, especially for frontages and anything near the right of way.
In most of Canada, choose cantilever slide for vehicles if you have the rack space. Swing leaves get blocked by snow.
Yes. The fence delays. Someone still has to detect and respond.
Overall height confirmed against the bylaw, including toppers. Rails on the secure side. Spacing chosen for delay, not looks alone. Bottom gap of about 50 mm over a concrete mow strip. Outward curved or extended picket top. Camera angles checked against picket depth. Snow storage shown on the site plan. Gates matched to the fence, with UL 325 operators and cantilever slides for vehicles. Hot-dip galvanized plus powder, with engineered footings.
Get those right and the fence does what CPTED intends. It tells people where the line is, lets everyone see across it, and makes crossing it slow, obvious and not worth the trouble.