Structural beam installation is required for any load-bearing wall opening in Ontario — whether removing a wall for open-concept or installing a new window in an exterior wall. This guide covers engineering requirements, OBC sizing rules, and 2026 GTA contractor costs.
Identifying Load-Bearing Walls
Load-bearing walls run perpendicular to floor joists and carry the weight of the structure above. In typical two-storey Ontario homes, all exterior walls are load-bearing. Interior load-bearing walls typically run perpendicular to floor joists (parallel to ridge).
Best method: inspect basement — load-bearing walls above appear directly over beams/posts supporting floor joists. A structural engineer can confirm in 1-2 hours for $300-$600.
OBC Prescriptive Header Sizing
For standard two-storey residential with one floor above:
- 1.8m (6 ft) opening: minimum 2 x 2x10 or 1.75x9.25 LVL
- 3.0m (10 ft) opening: minimum 3 x 2x12 or 1.75x14 LVL engineered beam
Beyond OBC prescriptive limits (over 3.5m, or non-standard loading): structural engineer specification mandatory.
Temporary Shoring Requirements
Removing a load-bearing wall requires temporary shoring while permanent beam and posts are installed. Shoring at 1.2m intervals minimum. Remove bearing only after new beam is fully supported on posts with footings confirmed adequate.
Costs (GTA 2026)
- Structural engineer assessment + beam sizing: $600-$1,500
- Load-bearing wall removal with beam (3-4m opening), full finish: $8,000-$18,000
- Building permit for structural work: $300-$800
Full technical guide: https://telegra.ph/Ontario-Structural-Beam-and-Header-Guide-2026---Sizing-Engineering-and-Costs-04-26