Can you laminate or glue sticks together in a bridge contest?
What lamination (built-up members) means, why it helps against buckling, and why some contests allow it only up to a limit while others ban it.
Updated · 1 min read
Short answer: it depends on the contest. Some allow built-up members up to a stated size, others ban gluing sticks face to face. Check the rules before you design around it.
What lamination is
Laminating means gluing two or more sticks side by side or face to face along their length, to make a bigger member from smaller sticks. A pair of 1/8 in sticks stacked becomes a deeper member.
Why builders do it
A bigger cross-section resists buckling far better, since bending stiffness rises quickly with depth. See preventing buckling. Laminating can also make a member of a size you can't buy.
Why contests restrict it
Rule-makers may want the stick sizes to be the real limit on the design. Some contests allow built-up members only up to a stated width, some ban any parallel gluing, and in at least one we have read even sticks offset so they barely touch count as laminated.
If it is allowed
- Keep the glue layer thin, and the sticks tight together.
- Remember glue adds weight.
- Stagger joints between layers so they don't line up.
If you're unsure whether something counts, ask the organizer in writing. See reading your rulebook.