Count rafters for a gable roof at your spacing and find the stock length to buy.
How it works
Half the building width plus overhang, times the slope multiplier, gives rafter length. Building length รท spacing plus one gives rafters per side.
Before you order
- Add a rafter at each end of any opening in the roof.
- Order 2 feet longer than the length when the math lands close.
- Sort for straight boards and put crowns up.
Common questions
How much overhang should rafters have?
Around 12 inches is common, though it changes with style and climate.
Does this size my rafters?
No. Rafter size depends on span, species, grade and loads, so use a span table for that.