What is rubble stone?
Rubble stone is unworked natural stone obtained directly from a quarry or by mechanical breaking, without further processing into a uniform size. The pieces have an irregular shape and size. Rubble stone is used as a foundation, retaining wall, decorative element or fill material.
Types of rubble stone
| Type | Description | Application |
|---|---|---|
| Limestone rubble | Light grey sedimentary stone | Walls, paths, decoration |
| Granite rubble | Hard, frost-resistant | Traffic lanes, bank protection |
| Sandstone | Reddish, easy to work | Decorative masonry |
| Slate | Flat-splitting stone | Facade cladding, garden paths |
| Porphyry | Extremely hard | Paving, cobblestones |
Applications
Foundation
In places without a solid subsoil, rubble stone was historically used as a foundation layer. Still used today when restoring historic buildings and garden walls.
Retaining walls and slope protection
Rubble stone is tipped loose or laid in mortar to retain soil. The irregular shape provides good interlocking between the pieces.
Garden decoration
As decorative paving, a dry-stone wall or border edging, rubble stone is popular for its natural appearance.
Drainage layer
Coarse rubble stone acts as drainage beneath terraces, decking and basement floors. Water can flow through freely.
Price indication
| Size | Weight | Price per tonne (indication) |
|---|---|---|
| Small (5-15 cm) | 1 tonne ≈ 0.4 m³ | €60 – €120 |
| Medium (15-30 cm) | 1 tonne ≈ 0.45 m³ | €70 – €130 |
| Large (>30 cm) | 1 tonne ≈ 0.5 m³ | €80 – €150 |
Prices depend on region and stone type.
Laying rubble stone
Laying rubble stone (also known as cyclopean masonry) requires a good eye for fitting the irregular pieces together. Use mortar of cement and sand (1:4). Smaller pieces can be used to fill large gaps.
Related terms
- Pad foundation
- Retaining wall
- Masonry bond
- Mortar
- Pointing mortar
- Strip foundation