It is one of the most versatile materials we have in design and construction. From delicate veneers and cladding, to massive solid treads, walls and sculptures, stone spans the reaches of our imagination.
Yet, most inventoried stone is limited to slabs 2 and 3cm thick. This means architects and builders will always find themselves in the position of wanting a custom stone solution capable of addressing the unique design and site requirements which inventoried stone will not meet.
Since the type of stone chosen has a huge impact on the outcome, we have created this checklist to identify the most important considerations and to help guide selection.
We believe that existing inventory shouldn’t limit what you can achieve.
John Williams Owner/President
Use this checklist to guide the stone selection by considering the 4As: Attributes, Application, Activity and Aesthetics™.
Submitting this form automatically subscribes you to future news and product emails from Yellow Mountain. If you do not want to receive future mailings, click on “Unsubscribe” at the bottom of the email sending you the Stone Selection Checklist link.
It is one of the most versatile materials we have in design and construction. From delicate veneers and cladding, to massive solid treads, walls and sculptures, stone spans the reaches of our imagination.
Yet, most inventoried stone is limited to slabs 2 and 3cm thick. This means architects and builders will always find themselves in the position of wanting a custom stone solution capable of addressing the unique design and site requirements which inventoried stone will not meet.
Since the type of stone chosen has a huge impact on the outcome, we have created this checklist to identify the most important considerations and to help guide selection.
We believe that existing inventory shouldn’t limit what you can achieve.
John Williams Owner/President
Use this checklist to guide the stone selection by considering the 4As: Attributes, Application, Activity and Aesthetics™.
Submitting this form automatically subscribes you to future news and product emails from Yellow Mountain. If you do not want to receive future mailings, click on “Unsubscribe” at the bottom of the email sending you the Stone Selection Checklist link.
Yellow Mountain StoneWorks is pleased to announce the addition of construction support services to the portfolio of support they provide their clients. These value added services leverage Yellow Mountain StoneWorks’ expertise in solving the unique kind of problems that can arise with innovative and complex stone designs and installations.
“Since we work across a wide range of projects types with a diverse set of team members, we are in the position to see the issues that have the potential to impact constructability or delay construction,” said John Williams, Owner and President of Yellow Mountain StoneWorks. “By offering construction services to our clients, we are able to anticipate and eliminate problems that would be disruptive and costly.”
Architects, landscape architects, builders, and installers can turn to Yellow Mountain to ensure that the artistry of the design is realized. “Yellow Mountain StoneWorks brings a tremendous amount of knowledge to the table, and that can make the difference between a good and great outcome,” said Tom Larson, senior project manager with John Kraemer & Sons. “You can count on them to be working for your success.”
Construction Services Highlights Supporting ground-breaking innovation
Special Mockups: Each project presents unique conditions. In some cases, being able to see a mockup of the stone as part of the design or installation process can make the difference.
Patination: A special patina which adjusts the color of the stone can be used to create a totally unique appearance. Work with our finish experts to achieve that special look.
Stone Connection Design and Configuration: We can design the system for attaching stone to vertical surfaces so that the difficulty and expense of field generated solutions can be avoided.
Back-up Framing Design: Integrating the stone wall into the overall structure requires a coordinated construction assembly. We can collaborate with the structural engineer on this.
Building Envelope Evaluation: Installation detailing can affect stone performance. For example structural steel can transmit cold to the stone and, in the wrong configuration, cause frost on the interior.Thermal performance is an important part of the evaluation we conduct.
ASTM Materials and Properties Testing: Custom testing to determine the performance characteristics of stone for your specific use are available. We support innovators trying new things.
Custom Finish Development: We are constantly exploring new stone treatments, making regular additions to the finishes that we offer. When it must be unique, we can work with you to develop a custom solution.
Richard Campbell is the Vice President of Operations for Yellow Mountain StoneWorks. During his tenure, Richard has grown our China-based team, strengthened our relationships with vendors, and honed our production processes to achieve greater efficiencies and scalability. We thought it would be interesting to share Richard’s perspective on doing business in China and his experiences helping us create a reliable supply chain. In part 1, Richard addressed the cultural aspects of running a production operation in China. In part 2, he speaks to quality control and meeting increased demand.
Ensuring quality control There are many elements that go into consistently providing a unique, quality stone product, on time, on budget – and produced in China. But to summarize, I would have to say it comes down to proactive communication and standards and processes that are clearly understood by our clients, staff and production vendors. Much of the detail of a given project is worked through during the development stage – this is when Yellow Mountain StoneWorks collaborates with our clients and works out the specifications for the stone. Once everyone agrees to the plan and standards we move to execution – and established quality control processes. For example:
Before production starts, there is always a meeting with the vendor and his staff to review the project drawings – which control the dimensions, and the control samples and mockup – which provides a visual standard. With the help of our staff translators and interpreters, we take the time to answer questions and make sure that our expectations are understood. Often, we put the control sample right where the artisans can all see it while they work to reinforce what will be accepted or rejected.
To further ensure quality, one of our QC inspectors is assigned long term to each production vendor where they monitor the progress of all Yellow Mountain StoneWorks projects. They inspect every piece of stone against the specifications and have cameras, laptops and phones to provide our project managers with reports of anything amiss. Our project managers oversee concurrent projects at multiple production facilities from our Xiamen office. The PMs are responsible for working with the owner of the respective production facility to problem solve issues.
Any piece of stone that is rejected is a cost to the production vendor. Having long term relationships with our Chinese production vendors has enabled us to show how proactive communication and quick alterations to production early in the process makes our projects more profitable for their business. That’s why the standards, the inspectors, the project managers – all the communication we do is to minimize the amount of stone we need to reject. This also helps to keep projects on schedule.
Scalability and Confidence A lot of companies build processes that work, but we made a conscious effort to build processes that work whether we have one project or a hundred projects. By having a standard operating procedure and clear quality expectations that everybody understands, we can focus on execution and scale production accordingly. This makes recruiting and training more efficient as well, because we simply integrate new hires into the existing process.
Being a company that operates in several locations, including on opposite sides of the Pacific Ocean, our processes also provide our management, staff and clients with the confidence that jobs are being done as expected. Whether I am in Xiamen or Seattle, or visiting a production facility, I know what the China team is doing on any given day because they’re following the standard operating procedure. I rely on them to do that, and they rely on me to do that. It keeps everything moving forward.
Richard Campbell is the Vice President of Operations for Yellow Mountain StoneWorks. During his tenure, Richard has grown our China-based team, strengthened our relationships with vendors, and honed our production processes to achieve greater efficiencies and scalability. We thought it would be interesting to share Richard’s perspective on doing business in China and his experiences helping us create a reliable supply chain. In part 1, Richard addresses the cultural aspects of running a production operation in China. In part 2, he speaks to quality control and meeting increased demand.
Forging a bridge between two cultures I pursued a career in international business because I am fascinated by contrasting economic models and I wanted a challenging, non-traditional job that involved different cultures. Working in China for Yellow Mountain StoneWorks is a perfect fit. China presents a complex and arduous business environment; the norms and assumptions of Western businesses simply do not apply.
For example, when we began talking with production facilities, we expected what Americans would call ‘the straight scoop.’ However, with surprising regularity, what we were told was not necessarily true – it was not necessarily untrue, but the Chinese often speak in innuendo, deflection, and obfuscation. It can be a matter of saving face or miscommunication or simply of habit. If you’re Chinese, I think culturally you’re more aware that things are not the way they are said to be and you adjust to interpretation. But our business is based on exact specifications and deadlines – and we must have confidence that our vendors will meet our standards.
To deal with this difference in communication style, we chose to invest in a few factories, not monetarily, but invest our energy and process and to stick with them long enough to see if we could find common ground. And slowly but surely, these relationships improved. And because we keep returning with orders, the vendors understand that working with us, in the way we need them to, creates a mutually beneficial alliance.
“A human company” Similar to finding the right production vendors, it has been important that our Chinese employees understand our approach, and see a value to themselves in meeting our rigorous standards and expectations. We talk a lot about only hiring the right people, good people. It has rightfully created a sense of pride among our employees and contributes to our company culture. When we need new hires, we often ask our existing project managers and quality control (QC) inspectors if they have recommendations, because they understand the kind of people we are looking for.
In fact, I was interviewing a good candidate for a QC inspector job and I told him, ‘We’re going to pay you fairly. We’re going to treat you fairly. We expect you to treat us fairly.’ The English translation of his response was, “I know, I know, they told me that. You’re a human company.” That was really good to hear because it is completely aligned with what we are going for. We value our team and want them to value the company because everyone plays an important part in our success.
Because stone is an organic material continuously influenced by elemental and human factors, designers and installers need to understand how different stones respond, both aesthetically and functionally, to different influences and over time. Testing stone against the demands of the finished project can be extremely helpful in selecting appropriate stones and finishes, preventing problems, and determining how a particular stone may perform after a given number of years. Armed with this knowledge, design and construction teams can make informed decisions and set realistic expectations.
“In essence, testing allows us to look into the future and predict how a given stone and finish is likely to perform in a specific design and environment,” explains Nicole Gelpi, Yellow Mountain StoneWorks Owner and Director of Marketing. “Testing provides a holistic picture of a stone which helps the project team collaborate on the best product and installation solutions.”
Advancing technology has created lab-based testing scenarios that can address a number of influential factors and be targeted specifically to the needs of an individual project, for example:
Freeze/Thaw Conditions: For projects located in environments with significant swings in temperature, testing looks at permeability and moisture absorption. When water freezes, it expands, which can lead to cracks and rupturing of material. During the thaw cycle, evaporation can cause minerals to crystallize, creating efflorescence deposits or pits on the surface of the stone. To test the effects of freeze/thaw conditions, the stone is immersed in water until it absorbs all the moisture it can and then frozen and thawed repeatedly. The integrity of the stone is based on X number of cycles along the continuum of testing.
Compressive Strength: Testing of compressive strength looks at the load capacity and can indicate how thick the stone needs to be to achieve the required strength. This is more likely to be an issue with softer stones, like sandstone. To test for compressive strength, increasing amounts of weight are put on top of the stone until it fails. The integrity of the stone is based on the average test results over multiple iterations using X number of sample sizes. Compressive strength testing, using scenario specific apparatus, can also determine a stone’s response to persistent weather conditions such as hail, wind, and salt spray.
Flexural Strength: The goal of flexural strength testing is to determine a stone’s ability to resist a load put on its surface asymmetrically, for example, a cantilevered stone with a load on the unsupported end. To test for flexural strength, the lab will cantilever a test section and then increase the unsupported load until it snaps, indicating the “bending moment.” The results of flexural strength testing can be particularly useful in indicating the best installation method for a given stone; for example, a sand set application with a pebble integrated in the subgrade can increase the flexural strength.
Chemical Resistance: When sulfurous, sulfuric, and nitric acids in polluted air react with the calcite in carbonate-based stones such as marble, travertine, and limestone, the calcite can dissolve resulting in roughened surfaces, removal of material, and loss of carved details. Testing involves exposing stone to chemical solutions resembling the acidity of the acid rain found in the relevant polluted environment. The integrity of the stone is based on X number of cycles along the continuum of testing.
Coefficient of Friction: Friction testing is used to determine slip resistance. A “slipping machine” is used to force of variety of replicated heels, i.e. barefoot, rubber soled shoes, high heels, etc., onto a stone at a given load to slide it sideways. Testing determines the coefficient of friction by showing the pounds of lateral thrust required to move the heel on the surface. Building codes require that exterior surfaces have a coefficient of friction of X, depending on use. Different finishes provide varying degrees slip resistance; testing multiple finishes allows us to help designers and builders achieve both aesthetic and functional requirements.
Testing stone is a proactive measure that allows a project team to evaluate different stones across multiple factors. Going beyond design and environment, test data can also influence decisions around budget and upkeep. For example, if test data shows that two different stones meet the strength and aesthetic requirements of a project, the team can confidently go with the less expensive option. In another scenario, if the owner has indicated they want a low maintenance solution, test data can help us to recommend stones and finishes that minimize maintenance.
On a final note, while testing can provide useful insight into a stone’s viability, it is not a guarantee of performance. “The reality is that installation trumps testing,” explains John Williams, Yellow Mountain StoneWorks Owner and President. “Testing results are based on simulated conditions that should inform the installation process specific to method, set material, drainage, air circulation, etc., but ultimately, the quality of the installation determines the performance of the stone.”
For a list of all relevant tests performed on dimensional stone, reference the standard guide published by ASTM International (formerly known as the American Society for Testing and Materials).
Intrinsic variability is what makes natural stone both beautiful and challenging. Limestones in particular can feature an array of desirable characteristics, such as veining, fossils, and color movement, yet these elements can vary in frequency, size and range within the same quarried block. Left uncommunicated and unresolved, the stone can fail to meet client expectations, alter the design intent, and potentially increase costs and time to completion if the client requires the stone be replaced.
“It’s critical to the success of a project to proactively manage expectations and collaborate on solutions that optimize the stone and meet the requirements of the project,” said John Williams, Yellow Mountain StoneWorks co-owner and president. “We look at the extent of the combined variables to drive the process – the richer the variables, the more involved the review points need to be.”
An excellent example of a more involved process is the recently completed Via6. Designed by GGLO and built by Lease Crutcher Lewis, Via6 is currently Seattle’s largest retail and residential complex. Covering half a city block, the design intent for Via6 was to communicate the high-end quality of the building by using high-quality materials with a handcrafted, artisan aesthetic. As a result, a granite and three unique limestones in various sizes and utilizing multiple, hand-textured finishes cover the 15- to 19-foot vertical height of the Via6 base.*
Limestones can be complex to define within design parameters, particularly on larger pieces, because of the mutable nature of its organic characteristics. It’s important to understand the nature of the stone and then create a set of standards, or a range, that meets the design intent and against which we can fabricate the required pieces. For example, how many fossils are too many, how big is too big; what is the size and visual quality of veining; what is the range of color? Defining the range too narrowly can result in more waste and higher costs; defining it too broadly can result in an uneven aesthetic.
“Yellow Mountain StoneWorks was incredibly helpful in educating our team about what stone is all about and to appreciate its natural, organic qualities,” said Steve Nordlund AIA, the project’s lead architect for GGLO. “We went through an extensive review and collaboration process that started with 6- and 12-inch square samples we could mull over in the conference room and ended with a trip to China to see full scale mock-ups.”
The initial smaller samples can help designers choose a color and texture palette, but the proof is in the full scale mock-ups Yellow Mountain StoneWorks provides because they most accurately show the range of color and likely occurrence of fossils and veining. As the final approval point, mock-ups also provide a reference point throughout production.
“On all of our projects, half of the mock-up goes to the client for review and approval, and half stays in China with the fabricator as a benchmark,” explained Williams. “But because of the scope of the Via6 project and the numerous variables in play, there was no substitute for being at the factory where we could collaborate in real time with our fabrication vendor and the Via6 developer, architect, builder, and stone installer.”
“It was important to have everyone there so that we could talk about the design as well as the construction and installation of the stone,” concurred Nordlund. “The full scale mock-ups allowed us to set parameters around the color range we wanted to achieve across the Ginseng Cream Limestone, and made clear the amount of veins in the Ink Jade Limestone – which enabled us to dictate where the pieces with more veining were placed in the project.”
“The ultimate outcome of the mock-ups is that we come to an assembled whole that looks correct,” explained Williams. “By correct, I mean that there isn’t any element that’s drawing undo attention to itself; the overall effect is a blend. This allows us to be more efficient throughout production by shifting the focus from an in-depth analysis of every piece, to the overall intent of the assembly.”
“Yellow Mountain StoneWorks was extremely helpful and knowledgeable,” said Nordlund. “Their process allowed the project to be completed as planned.”
*For more information about the scope and complexity of the project, go to our Via6 featured project page, “A Contemporary Jewel Box.”
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