Stone veneer

Stone veneer installation

Stone veneer is used as a protective and decorative covering for exterior or interior vertical walls and surfaces. The veneer is typically 1 inch thick and must weigh less than 15 pounds per square foot (73 kg/m2) so that no additional structural supports will be required.

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. This stone is often called thin stone veneer invented by Gernot Ehrlich.[1]

Manufactured stone veneer is a decorative building material manufactured to replicate the look of natural stone. The names artificial stones, faux stone, stacked stone veneer, manufactured stone, and flexible stone veneer are also used for manufactured stone veneer.

Fabrication

Manufactured Stone veneer is fabricated by pouring a lightweight concrete mix into rubber forms of different style and then painted with a coloring process which makes it resemble real stone. The stone veneer produced is then attached to walls with special mortars.

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.

Advantages

The advantages of manufactured stone veneer over natural stone are:

Manufactured veneer is cheaper than natural stone, approximately 1/3 to 1/2 the cost of natural stone. Its light weight eliminates the need for wall ties or footings and make it easier and cheaper to build. The variety of designs and colors makes available options which would not be available with natural stone, since natural stone is used in the general area around the locality which it is extracted.

There are also disadvantages for stone veneer compared to natural stone: It is not as strong as natural stone; if a piece breaks, or if a piece is removed from the wall, then unless it is replaced, it shows significantly; it is not reusable as natural stones are. Furthermore, manufactured stone veneer has a larger waste factor than natural stone. Natural stone can be chipped, cut, and shaped to any size needed. The cut off pieces can be reused. While manufactured stone veneer can not be cut to fit because it exposes the undesirable inner concrete from which the manufactured stone is made of. The user ends up with areas that require a small cut fill piece that has exposed concrete edges. Also, manufactured stone contains lime nuggets which can leech out and stain the surface over time when exposed to water. Manufactured stone is not a naturally occurring product and, due to its cast origin and painted exterior, it is subject to color changes caused by exposure to the UV in sunlight and moisture. Manufactured stone is a porous product. It absorbs much more water than real stone and it will transfer the moisture through to the wall of the structure causing many of the same issues seen with improperly installed stucco. Being a porous product manufactured stone is subjected to ice wedging and freeze thaw problems. As water seeps into the manufactured stone and then freezes, chunks of the face will pop off leaving a rugged edge which looks similar to the edge of a broken sidewalk. Repair can be expensive as the entire piece of stone must be cut out and replaced. The repair also doesn’t stop the issue from re-occurring.

The advantages of natural stone veneer over manufactured stone are:

Installation methods

There are several different methods for installing stone veneer. The substrate used will dicitate which installation method should be used.[2]

Historic building application

Its use is often prohibited by historic planning and conservation authorities as the material is typically not historically or geographically correct, giving an appearance to the building that it never originally possessed. Many new farm outbuildings in traditional rural areas in the UK are treated in this way.

History

Thin stone veneer was first developed in the late 19th century, but there were materials developed much earlier that foreshadowed the use of stone veneer. Parts of the Roman Coliseum were made out of marble veneer that can no longer be seen.[3]:27

In fact, the holes in structure of the Coliseum are from the anchors of the veneer panels. Structures throughout the Roman Empire were made in part out of stone blocks, including the Segovia aqueduct in Spain, which was made out of granite blocks. People in the Roman Empire also developed concrete (out of cement and rubblestone), which helped builders expand structures greater than before. Stone was used as a part of the facings of these new concrete structures in the Roman Empire, as seen in the Coliseum.[4]

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.[3]:28

One-and-½ inches became the common thickness of stone veneer in the 1930s. Panels of stone veneer were generally installed via mortar techniques, with steel rods drilled into the edges of panels providing support. 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.[3]:28

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.”[5]

“Diamond-studded cables” were used to cut Italian marble into the necessary slabs as a part of an era of specialization in the 1970s.[3]: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.”[6]

The thickness of 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.[3]:28

See also

References

  1. ↑ Slate Lite Stone Veneer
  2. ↑ Original Stone Veneer Product Page
  3. 1 2 3 4 5 Scheffler, Michael J. (2001). "Thin-Stone Veneer Building Facades: Evolution and Preservation". APT Bulletin 32 (1). JSTOR 1504690.
  4. ↑ Chacon, Mark A. (1999). Architectural Stone: Fabrication, Installation and Selection. Canada: John Wiley & Sons. p. 7. Retrieved 30 November 2011.
  5. ↑ 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.
  6. ↑ US 3950202, Hodges, William E., "Method of making a composite natural stone veneer product", published 13 April 1976
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