Rubble masonry is a form of masonry construction built from irregularly shaped, rough-broken pieces of natural stone. Known as “breuksteenwerk” in Dutch, it is one of the oldest building methods and remains in use today for retaining walls, landscape features, and heritage restoration.
Types of Rubble Masonry
Rubble masonry is classified by how the stones are selected and laid:
- Random rubble — stones of varying size and shape are laid without any attempt to form courses; the strongest bonds rely on careful fitting and generous mortar
- Coursed rubble — roughly levelled at regular intervals to form approximate horizontal courses, giving a more orderly appearance
- Squared rubble — stones are roughly dressed on their faces and edges to produce a more uniform look, while retaining an irregular character
- Polygonal rubble — stones are shaped to fit together with tighter joints and minimal mortar, often used in decorative walling
Construction Principles
Good rubble masonry follows several key rules:
- Each stone must bear on at least two stones below it
- Vertical joints should be staggered to avoid continuous weak lines
- Through-stones or bond stones should tie the wall from face to face at regular intervals
- Mortar must fill all voids to distribute loads and prevent moisture traps
- The wall core should be packed tightly, not left hollow
Application
Rubble masonry is used for garden and boundary walls, retaining walls, foundations in rural buildings, bridge abutments, and landscape features. In heritage construction it is essential for authentic restoration of medieval and vernacular buildings. Modern applications include decorative cladding and gabion-style landscape walls where a natural stone character is desired.
Related Terms
- Ashlar masonry
- Dry stone walling
- Natural stone
- Pointing
- Bond stone
More guides and plans available at fredsdiyplans.com