Tension Form

Beam action - Vertical reactions only
Compression Form

Arch action
    Horizontal thrust plus vertical reaction

Internal tension opposes internal compression

Shear parallel to grain seldom governs except at supports and for heavily-loaded short spans. Do not load timber in tension perpendicular to grain.
All internal compression

    The less the rise, the greater the
    horizontal thrust.
Tension and compression and radial tension
    Internal Ties                  External Bracing

      Hannahville School Gym (1992)
      Wilson, MI
      Architect: Sundberg Carlson & Assocs.
      Contractor: Champion, Inc.

Gymnasiums Page1