Stone veneer
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.
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.
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.
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.
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.
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Wikipedia