![cover image](https://wikiwandv2-19431.kxcdn.com/_next/image?url=https://upload.wikimedia.org/wikipedia/commons/thumb/3/35/Rubble-fill-wall.jpg/640px-Rubble-fill-wall.jpg&w=640&q=50)
Rubble masonry
Type of building stone / From Wikipedia, the free encyclopedia
Rubble masonry or rubble stone is rough, uneven building stone not laid in regular courses.[1][2] It may fill the core of a wall which is faced with unit masonry such as brick or ashlar. Some medieval cathedral walls have outer shells of ashlar with an inner backfill of mortarless rubble and dirt.
![Thumb image](http://upload.wikimedia.org/wikipedia/commons/thumb/3/35/Rubble-fill-wall.jpg/640px-Rubble-fill-wall.jpg)