A fence looks simple until the first winter. Then the posts heave, the gates won't close, and the whole run leans like it's had a long night. Here's how to build a fence that stays straight in Simcoe County soil.
Post Depth: Below the Frost Line
Same rule as decks: fence posts need to go below the 4-foot frost line. This is the single most important factor in whether your fence survives its first winter.
What works:
- 4x4 or 6x6 pressure-treated posts set in concrete, with the concrete footing extending below 4 feet
- Post holes dug to 4+ feet, concrete poured around the post
What doesn't:
- Posts set 2 feet deep "because digging is hard"
- Spikes or post anchors driven into the surface (fine for a temporary garden border, not for a real fence)
- Dry-packing concrete mix around the post without water (it never fully cures)
Taper the concrete so the top is wider than the bottom — shaped like an upside-down mushroom. This sounds backwards, but frost grips the sides of a straight cylinder and lifts it. A tapered footing resists that upward grip.
Concrete: The Details Matter
- Use concrete, not just gravel, for structural fence posts
- Crown the concrete slightly above grade so water runs away from the post (standing water rots wood faster than anything)
- Don't bury the post in concrete all the way to the surface in a way that traps water against the wood — the crowned top helps, and some builders wrap the below-grade portion
Property Lines: Sort This Out First
Before you dig a single hole:
- Get a survey or locate your property stakes. Guessing the line is how neighbour disputes start.
- Talk to your neighbours. Even if the fence is entirely on your property, a heads-up prevents bad feelings. If you want to split the cost of a shared fence, get the agreement in writing.
- Check municipal bylaws. Barrie and Orillia both regulate fence height — typically 6 feet max in back yards, lower in front yards. Corner lots have additional sight-line restrictions.
- Call for locates (Ontario One Call) before digging. Hitting a gas line or buried cable turns a weekend project into an emergency.
Gates: Where Fences Fail
Gates are the moving part, so they're where problems show up first. Build them right:
- Oversize the gate posts — use 6x6 instead of 4x4 for any post carrying a gate
- Set gate posts deeper and with more concrete than line posts
- Use proper gate hardware — strap hinges and a real latch, not repurposed door hinges
- Build the gate frame with a diagonal brace running from the bottom hinge side to the top latch side (this prevents sagging)
A sagging gate is almost always a post problem or a missing diagonal brace. Both are preventable.
Wood Choices
- Pressure-treated lumber: the standard; affordable, lasts 15-20 years with maintenance
- Cedar: looks better, naturally rot-resistant, costs more, lasts roughly the same with less chemical treatment
- Whatever you choose, stain or seal within the first year — UV breaks down unprotected wood fast
How Long It Should Last
A properly built fence in this region — deep posts, good drainage, maintained wood — should last 15 to 25 years. A fence with shallow posts might look fine in September and be leaning by April. The difference is entirely in the holes nobody sees.
Concepts Construction — Barrie and Orillia, Ontario. Need a fence that stays straight through winter? We'll dig the holes right the first time. Free Estimates. Honest Solutions. (705) 330-2911.
