Random rubble and dry rubble masonry

Random rubble masonry

Rough, irregular stones, in the shape in which they come from the quarry, are laid without any definite courses. Mortar (1:6 cement-sand or lime) fills the gaps, and smaller stones fill the voids. Through (bond) stones are placed at about 1.5 m spacing to bond the full thickness of the wall. The minimum wall thickness is about 400 mm.

• Uncoursed: no courses at all; cheapest.
• Coursed: brought to a level at every 300-350 mm height, forming rough courses.

    ___ ____ __ ___
   /   \    \  \   \   irregular stones, thick
  /__ __\____\__\___\  and irregular joints
  \  /  /   /\   /
   \/__/___/__\_/

Dry rubble masonry

Rubble stones are laid without any mortar; stability depends on proper interlocking and the weight of the stones. Large stones are used at the bottom, and bond stones are placed across the thickness.

• Stones are carefully selected and fitted; small stones (chinking) are wedged into the gaps.
• The wall thickness is large (about 600 mm at the base) and the height is limited.
• Used for temporary works, boundary walls, retaining walls in hilly regions and terraces, where economy is important and drainage is needed.

   ___  ____  ___
  |   \/    \/   |   stones interlocked,
  |__/\  __  /\__|   no mortar
  |  \ \/  \/ /  |
  |___\_/\__/\___|