Cedar vs Pressure-Treated Fence Posts: Pros and Cons

The debate between cedar and pressure-treated lumber is one of the most common questions in Canadian fence installation. Both are legitimate, widely-used options — but they perform differently in different parts of the fence, and the smartest installations actually use both materials strategically. Understanding the strengths and limitations of each helps you ask the right questions when getting quotes and ensures your fence is built to the right spec for your budget and your climate.

Cedar is a premium natural wood valued for its beauty, natural rot resistance, and dimensional stability. Pressure-treated lumber is wood that has been chemically impregnated under pressure to resist rot, fungi, and insects. It is less expensive and performs better in direct ground contact. In most Canadian fence installations, the ideal combination is pressure-treated posts with cedar boards and rails — giving you the best of both worlds.

H2: Cedar Fence Posts — Strengths and Limitations

Cedar's natural oils provide genuine resistance to moisture and decay, making untreated cedar a respectable option for fence posts in well-drained soils. Above-ground, cedar is exceptional: it resists warping, checking, and splitting better than pressure-treated pine, takes stain beautifully, and has a warm natural appearance that many homeowners prefer.

The limitation for cedar as a fence post material is performance in soil contact. While cedar's natural oils provide meaningful protection, they are not as durable in the constantly moist underground environment as chemical pressure treatment. In Ontario and Quebec soils — which are often clay-heavy and retain moisture — cedar posts in direct soil contact typically last 10 to 20 years. In well-drained sandy soils, cedar posts can perform for 20 to 25 years.

Cedar costs roughly $20 to $35 per linear foot installed for a complete cedar fence, making it a mid-to-premium product. If cost is a factor, using pressure-treated posts but cedar boards is a common and effective compromise.

H2: Pressure-Treated Fence Posts — Strengths and Limitations

Pressure-treated lumber is engineered specifically to resist the conditions that kill wood: moisture, fungi, and insects. For posts going into the ground, pressure treatment rated UC4B (for general ground contact) or UC4C (for severe conditions) significantly outperforms untreated cedar in direct soil environments. Pressure-treated posts in Ontario soil typically last 20 to 30 years, compared to 10 to 20 for cedar in the same application.

The trade-offs are visual and practical. Pressure-treated wood has a greenish cast when new and is less attractive than cedar. It must cure for approximately six months before accepting stain or paint. It is also heavier and slightly harder to work with. Some homeowners have environmental concerns about the copper-based preservatives used in modern pressure treatment, though current formulations (ACQ and CA-C) are considered safe for residential use and do not contain the arsenic compounds that were phased out in the early 2000s.

Pressure-treated lumber typically costs 30 to 40% less than cedar — roughly $15 to $25 per linear foot installed for a complete pressure-treated fence.

H2: The Hybrid Approach — Pressure-Treated Posts with Cedar Boards

The approach favoured by most experienced Canadian fence contractors is to combine both materials: pressure-treated posts set below the frost line in concrete for maximum ground contact durability, and cedar boards and rails above ground for appearance and dimensional stability. This gives you the engineering advantage of pressure treatment where it matters most (soil contact) and the aesthetic advantage of cedar where it is most visible.