How to calculate rafter length?
The formulas we use are the following:
- For calculations based on the roof rise:
rise² + run² = rafter length²
rafter length = √(rise² + run²)
Roof pitch
Pitch – Is the incline of the roof represented as the ratio of rise to the span (twice the run). For example, if the roof rises 4 feet and the span is 16 feet, then the pitch is 4/16, or 1/4.
What is the distance between rafters on a roof?
Typically either 12, 16 or 24 inches apart (measured "on center" from one rafter's center to the next).
What is the maximum span for a 2×6 rafter?
16 feet 5 inches (12" OC), 14 feet 8 inches (16" OC), and 12 feet 8 inches (24" OC).
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What is the rafter length?
The length of the rafter is given from the long point of the ridge cut at the top down along the top edge to the plumb cut on the rafter’s notch.
Rafter span
Rafter span is the distance between the supporting wall and the centre of the roof measured horizontally.
Can you span 16 feet with a 2×6?
Grade 2 2×6 joists can span up to 10 feet 9 inches (16" OC).
How far can a 2×8 rafter span without support?
In general: 12 feet. Depending on various factors, spans can range from 6'-7" to 23'-9".
