Once the full-bed stone has been selected and puzzled together for a specific area, the installation begins. First a concrete mixture of rock, sand, and cement is poured, creating a footing for the stone. Then each individual stone is positioned in the footing and set with mortar. As the individual stones are set in place, stonemasons continue to cut and chip away to create stones that are the right size and shape for the project. If the space has corners that need to be covered in stone, the stonemason makes the cornerstone pieces by hand. After all of the stones were in place, the mortar between the stones, also called grout joints, was groomed and the excess mortar was cleaned from the stones.

Beyond the labor-intensive installation, the use of full-bed stone creates extra tasks and areas of concern on the job site. Repeated on-site cutting creates extra dust and materials for disposal and the palettes of rock are difficult to move.

Poor Color Consistency/Uniformity
The traditional process also made it difficult to provide rock to a job site that was consistent in color or uniform in shape. Natural stone is formed in mountains or large pools of bedrock, not produced to specification on a manufacturing floor. The geology can change from one area of a quarry to the next, producing stones of different color characteristics and textures. Stone collected from one area may be patchy or discolored, darker or lighter than stone collected for the same project, but from a different part of the quarry. While these natural variations may be unnoticed when peppered throughout the entire delivery, these rocks were often packaged as they were mined, so all of the discolored rocks may be on one pallet, or perhaps the darker rocks were delivered first and lighter rocks last.  If the rocks were not mixed by hand by the stonemasons, walls built from rocks that arrived on the first pallet may not match subsequent walls built from rocks quarried from a different area.

Design Challenges
Design teams value the aesthetic richness that natural stone brings to a project. However, they also value product consistency. There were so many variables in creating full-bed stone veneers that architects rarely knew what the final product would look like until it was finished.  Specifiers were not confident that the stone selected for a project would be the stone delivered to the project. It could be lighter, darker or patchier than the original sample that was specified. Additionally, the look of the final stone surface relied heavily on the skill and personal style of the stonemason, which would vary from project to project.   

If the design called for stone to be used on any combination of exterior, interior, or floor spaces, simply finding the necessary materials was often challenging. The type of veneer would change based on its location. For instance, an exterior veneer may incorporate larger or more clefted stones, while interior veneers may require stones that are longer, thinner and flatter. Even though the style and dimension of the stone on a project varied, the color was supposed to remain the same.  If one vendor was unable to provide the same stone quarried in these different styles or dimensions, then design teams were often left to the complicated task of trying to match stones from different sources.  

Difficult Job Costing
Working with an inconsistent material that is difficult to install makes it hard for contractors to create an accurate estimate of how much the job will cost.  There are simply too many variables when working with full-bed stone. Poor job costing often created many friction points throughout the construction process as real costs escalated and construction timelines slowed.

The Artificial Answer: Artificial Stone

The aesthetic appeal of stone as a building material coupled with the significant shortcomings of specifying actual bedrock spurred an investment in creating an alternative to natural stone. In the early 1960's, artificial stone was introduced into the construction industry.  

 Most artificial stone is created by placing white and grey cement, sand, gravel and color pigments into a mold designed to look like real stone. Some manufacturers also paint the inside of the mold to add desired tones to the surface of the faux-rock product. These artificial rocks are then packaged and shipped to a job site as either individual stones or in pre-fabricated modular panels. With this controlled production process, artificial stone successfully addresses many of the design and installation issues inherent in the traditional creation of full-bed natural stone veneers.  

Improved Rate of Production and Simplified Installation
When artificial stone is manufactured and shipped to a work site, it is the right color and the right size for the project and it is ready to be installed. Stonemasons are no longer responsible for the on-site quality control of each individual piece of stone. Artificial stones cannot be chipped and shaped on-site, because it will destroy the stone exterior. They are delivered in the size and shape in which they should be installed. This allows lesser skilled or experienced masons to work on projects, which further decreases labor costs.

When working with loose artificial stone, stonemasons begin by piecing together individual stones to create the desired wall, fireplace or floor, etc. When the artificial stones are delivered in modular panels, product installation is further simplified. Instead of piecing together the individual stones, stonemasons fit the pre-made panels together and join them as seamlessly as possible.

Artificial stone is made with a light-weight aggregate to minimize the weight of the product.  These lighter materials do not require a foundation, or footing, and are mortared directly onto the side of the structure that they are disguising. Cement mortar, known as a "scratch" or "brown" coat, is applied onto the surface of the structure and buttered onto the back of the artificial stone. The concrete product is then pressed to the structure to adhere.

Consistent Color
The consistency of color that was impossible to dictate on a mountain-side is much more easily managed in a manufacturing facility. Artificial stone is developed to a specification, like many other manufactured products, and is not affected by the natural variations in geological processes. Additionally, if a certain artificial stone was selected to be applied throughout an entire development, the product that arrived to outfit the final house on the project would be a uniform match to the first artificial stones installed.

Accurate Job Costing
The factory-manufactured product paired with a significantly simplified installation process removed many of the variables that made it difficult to create an accurate job estimate.  Using artificial stone was slightly more predictable than loose natural stone and, therefore, design teams and construction estimators were better equipped to deduce the total costs of the project.

Design Consistency
Another benefit of using artificial stone products was that the design of a wall, column, or cobbled floor was no longer determined by the expertise of the installation team.  Specifiers could specify an artificial stone wall for a project and know almost exactly how the end result would look.  This predictability gave design teams a confidence in the ability of this final product to meet their initial design standards.

Synthetic Limitations

Artificial stone successfully addressed many of the shortcomings that existed in the way that bedrock was traditionally incorporated into a construction project.  However, these man-made products were unable to surpass, or even duplicate, nature in a number of important areas. 

Artificial Appearance
While this color-specified, man-made material may eliminate inconsistency on a project, it also removes the variations and imperfections that are expected and adored in natural objects. Artificial stone systems will deliver identical stones that create a uniform aesthetic throughout a project. However, to truly look like a natural stone surface, there is a certain level of variability in both texture and color must exist in the material.