The Core Difference: How They Fail

Fiberglass and steel doors both have their place, but they fail in very different ways. Steel doors are prone to dents, rust at the edges, and can warp when exposed to extreme temperature swings — a real problem in Ontario winters. Fiberglass, on the other hand, resists moisture and denting, but cheaper fibreglass can feel hollow and look plasticky up close.

At the premium end, both materials can be excellent. A properly insulated steel door with a thermal break is surprisingly energy-efficient. A high-density fiberglass door stained to look like wood can be indistinguishable from the real thing from the street. The key question isn’t really material — it’s quality of construction and finish.

Our Honest Recommendation

For most Ontario homes, we lean toward fiberglass — specifically for its long-term durability in freeze-thaw cycles. A well-made fibreglass door from a reputable manufacturer will outlast steel in our climate, hold its finish longer, and require less maintenance over a 20-year period. That said, budget matters: a mid-range steel door will always outperform a cheap fibreglass one.