How to tie it
- 1Start with a timber hitch around both poles where they cross, pulled tight so the two poles are drawn together — this closes any gap.
- 2Make about three wrapping turns diagonally across the cross in one direction, around both poles.
- 3Make about three more wrapping turns diagonally the other way, crossing the first set, pulling the poles together along both diagonals.
- 4Make two frapping turns between the poles, around the wraps, pulled tight to cinch everything.
- 5Finish with a clove hitch around the more convenient pole and lock the end.
Remember it as
Wrap thrice, frap twice.
When to use it
- Cross-bracing the diagonal member of a trestle, tower, or frame to keep it from racking.
- Any joint where two poles cross but don't touch, or spring apart under load.
- Combined with square lashings in larger pioneering structures — bridges and towers use both.
Common mistakes & safety
- This is a structural, load-bearing joint. A failed cross-brace lets the whole frame rack and collapse. Inspect poles for cracks and rot, and size the rope to the load.
- The timber-hitch start must spring the poles together. If you don't cinch the gap closed at the start, the finished lashing stays loose and the brace does nothing.
- Tight fraps are the key. Loose fraps mean a loose joint that shifts under load.
- Use the right lashing. Poles that already press together take a square lashing (stronger for that case); poles that spring apart take a diagonal lashing.
- Lock the finishing clove hitch. If it slips, the wraps unwind.
Going deeper
- Why a timber hitch to start. The timber hitch can be thrown around both poles and pulled tight to draw them together — exactly what you need before wrapping a gap-crossing brace. (Its other headline job is dragging logs.)
- Both diagonal directions matter. Each set of diagonal wraps resists the poles sliding one way; together they lock the cross in both directions, which is why you can't skip either set.
- The one-line rule. Poles that press together → square lashing; poles that spring apart → diagonal lashing.
Official source
Diagonal Lashing on Knots3D →Pioneering methods and official wording live with Scouting America. Confirm the current technique and safety guidance at scouting.org before building anything people will climb or stand on.