Stone veneer

Stone veneer is a thin layer of any stone used as decorative facing material that is not meant to be load bearing. Stone cladding is a stone veneer, or simulated stone, applied to a building or other structure made of a material other than stone. Stone cladding is sometimes applied to concrete and steel buildings as part of their original architectural design.

Thin stone veneer was first developed in the late 19th century, but there were materials developed much earlier that foreshadowed its use. For instance, the ancient Romans built large structures out of Roman concrete, and sometimes used a form of stone veneer to face them. Parts of the Roman Coliseum were originally faced with marble veneer; the holes which once held the anchors for the veneer are still visible.

Modern stone veneer first made its appearance in the late 1800s. The oldest of modern stone veneer product is now disintegrating. It was cut into thick portions and then hand tooled into the appropriate panels; the stones that were used were "granite, marble, travertine, limestone, and slate." Early in its development, thin stone veneer only had the capabilities to be utilized in areas such as the inside of buildings, street-level facades and storefronts.

In the Late 19th and early 20th centuries non-load-bearing stone veneers were regularly affixed to load-bearing walls behind. As buildings began to grow taller with the advent of skeletal steel framing, it became necessary to diminish the thickness and weight of masonry walls in order to withstand the dead weight of the building. Without steel supports, load bearing walls could grow several meters thick on their lowest stories. A solution employed in the construction of early skyscrapers was the use of a steel structural frame that supported exterior stone walls at every floor, thereby distributing the load into the frame. This avoided a gradual buildup of weight that resulted in inconveniently thick lower walls. The Empire State Building uses this method, having two steel beams for attaching stone veneer on each floor; one inside to bear weight, and one acting as a shelf outside to support the building's limestone veneer. One and a half inches (38 mm) became the common thickness of stone veneer in the 1930s. The utilization of thin stone veneer for complete facades of buildings popped up in the 1940s. Stone veneer construction became much of what we see today in the 1950s. Transportation improved, so stone veneer was transported more efficiently and at lower costs than ever before. Methods to attach veneer to steel were developed; diamond-bladed tools became popular for developing thin stone veneer, while elastomeric sealant began to replace mortar techniques in the construction process. Thin stone veneer in the 1960s became more of a standardized look – in fact, standard education on stone veneer became available in The Marble Engineering Handbook and Marble-Faced Precast Panels, which were published by the Marble Institute of America and National Association of Marble Producers.

As stone veneer panels got thinner in the 1960s, the properties of the stone used became more important in order to compensate (as did safety considerations). Concrete as an aid to stone veneer continued to develop, as "in order to eliminate bowing, cracking, and staining of the veneer."

"Diamond-studded cables" were used to cut Italian marble into the necessary slabs as a part of an era of specialization in the 1970s. A 1976 patent shows that the stone material of composite stone veneer could be finished and developed in such a fashion that "it does not have the appearance of being a part of a composite stone veneered product."

The stone veneer was able to be cut to a thickness of 1⁄8 inch (3.2 mm) in the 1980s because of improvements in technology. The thickness of typical thin stone veneer was three centimeters by the early 2000s. Anchors of support were provided by a specific type of stainless steel or "of aluminum with a non-corroding material separator between the metal and stone." These anchors are attached to the back of the panels with a rod.

There are a variety of systems for attaching stone veneers to facades including dowel, kerf, and undercut anchoring systems as well as direct fixing.