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.
History
 | This section may lend undue weight to certain ideas, incidents, or controversies. (June 2018) |
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
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.[2]: 28
In the Late 19th and early 20th centuries non-load-bearing stone veneers were regularly affixed to
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."[4]
"Diamond-studded cables" were used to cut Italian marble into the necessary slabs as a part of an era of specialization in the 1970s.[2]: 28 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."[5]
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.[2]: 28
Systems
There are a variety of systems for attaching stone veneers to facades including dowel, kerf, and undercut anchoring systems as well as direct fixing.
The direct or adhered fixing system relies on a mortar or cement bonding between the substrate wall and the backside of the stone veneer. This application is generally used indoors as exterior weathering and temperature extremes cause the veneer to crack and spall. The complete connection between the veneer and substrate does not account for differing rates of thermal expansion between materials, causing them to bind under pressure.[6]
Most exterior veneer systems hang stone from a support wall by pins and anchors allowing air space between, essentially using stone as a
A fourth and somewhat less common anchoring system is the Undercut anchoring system which uses an expansion ring on the end of a bolt to lock into an undercut hole in the back of a veneer panel. Pressure from tightening the bolt causes the expansion ring to flare out, filling the undercut hole. The bolt is then affixed to anchorage system connected to the supporting wall behind.[6]
Materials
Stone veneer can be made from natural stone as well as manufactured stone. Natural stone veneer is made from real stone that is either collected, i.e. fieldstone, or quarried. The stone is cut to a consistent thickness and weight for use as a veneer.
Manufactured products
Flexible stone veneer is fabricated by pulling a thin layer of stone from a slab of slate, sandstone, or mica schist. It is backed by a composite material.
Cladding
Stone cladding often consists of a lightweight simulated stone products with a concrete-type base. These stone cladding products are often fitted to lightweight substrates to reduce the material cost of construction; this would typically comprise
- timber stud frame
- waterproof barrier
- fibre cement sheet
- expanded metal mesh
- mortar scratch coat.
Then, using a mortar mix, the stone cladding would be affixed to the wall. In the US, a typical installation on a lightweight substrate would use plywood backing as an alternative to fibre cement sheet.
Alternatively, stone cladding can be a natural stone that has been quarried and then cut into thin pieces to reduce weight.
Being heavier, natural stone cladding often needs mechanical fixing to be adhered to substrates. Mechanical fixing could be using shelf angles, or perhaps a product called stone clip.
Several methods or systems are available for installing stone on the exterior of buildings.[6]
See also
- Ashlar — solid and clad/veneered stone wall style
- Masonry veneer
- Pebbledash— exterior decorative veneer
- Wythe, a section of masonry
References
- ^ Chacon, Mark A. (1999). Architectural Stone: Fabrication, Installation and Selection. Canada: John Wiley & Sons. p. 7. Retrieved 30 November 2011.
- ^ JSTOR 1504690.
- ^ ISBN 978-0-471-14415-1.
- ^ Donaldson, B. (1988). New Stone Technology, Design and Structure for Exterior Wall Systems. Baltimore: American Society for Testing and Materials. p. 89. Retrieved 20 October 2011.
- ^ US 3950202, Hodges, William E., "Method of making a composite natural stone veneer productp", published 13 April 1976, page 3.
- ^ a b c d e Stone Cladding Engineering | Rui de Camposinhos | Springer.
- ^ Murray, Lorraine. "Christ the Redeemer (last updated 13 January 2014)". Encyclopædia Britannica. Retrieved November 29, 2022.
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