24 Foot Gambrel Roof Truss Calculator
24 ft is the most common residential gambrel width in North America. It fits a two-car garage at 24×24, a classic four-stall horse barn at 24×36, or a generous residential cottage with full second-story headroom under the gambrel knuckle.
Pre-Calculated Results for 24 ft Span
| Sweep Angle | Lower Rafter | Upper Rafter | Total Height | Roof Area (20 ft L) |
|---|---|---|---|---|
| 45° | 16.97 | 0.00 | 12.00 | 791 |
| 60° | 12.00 | 6.21 | 12.00 | 845 |
| 67.5° | 9.18 | 9.18 | 12.00 | 852 |
The Reference Case
At 24 ft wide with a 60° lower sweep, the half-circle method sets the upper sweep to 15°. The lower rafter is 12.0 ft and the upper rafter is 6.21 ft. Total height above the wall plate is 12.0 ft. These are the numbers most published gambrel plans assume by default.
Two-Car Garage Layout
A 24 ft wall fits two standard 9 ft × 7 ft overhead doors with 2 ft of jamb between them and 2 ft on each outside edge. The 12 ft attic above is enough for full-height storage of seasonal items, lumber, or a basic workshop loft.
Typical Applications for a 24 ft Gambrel
A 24 ft wide gambrel is sized for two-car garage, residential gambrel, mid-size barn. With a 60° sweep angle the lower rafters land at 12.00 ft and upper rafters at 6.21 ft, both within the capacity of 2×8 SPF #2 for typical residential loads at 16 in on center rafter spacing.
Total roof height at the standard 60° sweep is 12.0 ft above the wall plate. Loft floor area inside the knuckle is approximately 12.0 ft wide and runs the full length of the building, usable for storage, a sleeping loft, or a workshop above the main floor.