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Why shoring; racking versus flying shore

Short answer

Shoring is necessary to prevent collapse of weak, leaning, or cracked walls, support adjoining buildings during demolition or excavation, and carry loads during alterations or repairs. Raking shores use inclined rakers (60-70°) from ground to wall plate, requiring open ground space. Flying shores are horizontal members between two parallel walls, supported by needles and struts, keeping ground free and suitable for gaps up to 9 m.

Why is shoring necessary? Compare raking shores with flying shore.

Why shoring is necessary

  • A wall is bulging, leaning or cracked and may collapse.
  • An adjacent building is being demolished, or an excavation is made nearby.
  • The foundation of the building is weakened (settlement, flood, underpinning work).
  • Alterations: removing a wall, opening or pier that carries load from above.
  • Damage from an earthquake, fire or vehicle impact.

Raking shore versus flying shore

PointRaking shoreFlying shore
Position of membersInclined (60-70 degrees)Horizontal
Support fromGround, outside the wallThe opposite wall
Touches groundYes (sole plate)No; carried entirely by the two walls
Suitable whenA single wall, with open space beside itTwo parallel walls close together (up to about 9 m)
ComponentsRakers, wall plate, needles, cleats, sole plate, bracesHorizontal shore, wall plates, needles, struts, straining pieces
Space neededMore on the groundLess; ground kept free
CostUsually higherLower
 RAKING                        FLYING
  wall|\                    wall||=====shore=====||wall
  wall| \ raker             wall||  /         \  ||wall
  wall|  \                  wall||/ strut  strut\||wall
 _____|___\____ sole plate

✓ Answer checked by Claude Opus 5.5 (high effort)

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