Thursday, December 23, 2010

A Sustainability Standard for Natural Stone


I have recently become involved with the NSF Joint Committee on Natural Stone which has the goal of developing a sustainability standard for natural stone. This is a consensus committee of multiple stakeholders that, with the assistance of NSF International and Ecoform, will develop an ANSI Standard that is intended to offer the following benefits to the stone industry, as stated in a recent press release from The Natural Stone Council:

Establish a set of well-defined environmental and human health metrics recognized by the green building movement as an indicator of leadership sustainability performance.

 Provide an important opportunity to educate key members of the green building movement, government, and environmental advocacy groups about the production of stone products.

 Create a mechanism that rewards natural stone companies that demonstrate environmental leadership through commitment to sustainable operations and continued innovation.

 Proactively address potential stone-related environmental and human health concerns in a multi-stakeholder science based forum (i.e. radon, dust, etc.).

 Harmonize national and international environmental requirements for stone quarrying and production.

 Encourage transparent chain of custody reporting in support of LEED credits for locally produced materials.

 Create parity between stone and other competitive products covered by existing certification programs.

Please click on the highlighted link for a copy of the kickoff presentation for the Consensus Standard for Dimensional Stone NSC 373

Completion of the standard is projected to be early Spring, 2012.

Saturday, November 20, 2010

Sustainable Natural Stone

What is Sustainability?

According to Wikipedia's definition "Sustainability is the capacity to endure."

Thanks to wonders of modern technology you can step into some of the oldest and greatest buildings in the world and take a virtual tour of their architectural details.

Take a look at the interior of the Sistine Chapel at the Vatican in Italy at the following link

The frescoed works of Michelangelo, Botticelli, Bernini and Raphael, some of the greatest Renaissance artists, are on display on the walls and the famed ceiling of the Chapel after a controversial restoration in 1984. However, left click your mouse to scroll downward and look at the marble flooring. This is a pattern of natural stone inlays done in the Cosmatesque style, taken from the Cosmati family name, the leading marble craftsmen in Rome through the 12th and 13th centuries. Built between 1473 and 1481, the first mass in the Sistine Chapel was celebrated on August 9, 1483. Talk about sustainability. Over 500 years of service and it is said that the stone used by the cosmati artists were salvaged material from the ruins of ancient Roman buildings. Sustainable natural stone flooring at its best.

If you are interested in touring some other great architectural works with sustainable marble flooring take a look at St Peters Basilica and the Pantheon via the links below. Click on the virtual tour arrow and go to fullscreen then move your mouse pointer down to view the flooring.

St. Peters Basilica
Vatican City

The Pantheon
Rome, Italy

Please let me know if you have any stories or other building references for sustainable natural stone.

Sunday, October 24, 2010

Anchoring Dimensional Stone

The Marble Institute of America (MIA) is an industry association that is "Setting the Standards in the Natural Stone Industry". As stated on their website "The MIA is the largest trade association in the world to represent the dimension stone market, and for over 65 years, it has been the leader in providing advocacy, networking, marketing/publicity, information/education, professionalism and stone craftsmanship."

Periodically the MIA issues Technical Bulletins relating to subjects pertinent to the design and construction of natural dimension stone. Generally only available to the MIA membership, a free download titled "Dimension Stone Anchorage Theory, Practice, & Components" is being featured on Architecture Week's website this month. Click on the link below and check it out!

As stated on the Architecture Week's website, this is "a technical bulletin on the practice of mechanically anchoring dimension stone. Prepared as a general guide for tradespeople, the bulletin provides valuable insight about how stone-anchorage devices interface with the stone panels and the building structure. Common anchorage devices are discussed, as well as some guidance about why certain anchor device selections may be more appropriate than others in particular situations."

If you find that the anchorage information in the MIA technical bulletin is valuable to you may want to purchase the Dimension Stone Design Manual, VII. This is the stone industry's single source reference for dimensional stone design and construction facts and details and in my opinion an invaluable resource.

The Dimension Stone Design Manual, VII is available for purchase by MIA members as well as non-members. You can purchase online from the MIA website. You will find a more detailed description and links to the MIA online store by clicking in the following link.

Saturday, September 11, 2010

Remembering 9/11 and the Freedom Tower Cornerstone

Most Americans remember where they were and what they were doing on September 11th when the New York World Trade Center buildings were attacked by terrorists. Nine years have passed and the wounds remain. Today we mourn the loss almost 3,000. A ceremony at the site today was opened by brief comments from Mayor Bloomberg. "Once again we meet to commemorate the day we have come to call 9/11. We have returned to this sacred site to join our hearts together, the names of those we loved and lost," Bloomberg said. "No other public tragedy has cut our city so deeply. No other place is as filled with our compassion, our love and our solidarity."

Construction of Freedom Tower /One World Trade Center is finally progressing after many delays which were the subject of a recent 60 Minutes expose. At one point in time the Tower was projected to be completed in 2009. Back in June of 2004 I was involved with the management of the Freedom Tower cornerstone preparation and installation for the initial groundbreaking ceremony when I was Director of Installation for Innovative Marble & Tile LLC. I was proud to be there at Ground Zero on July 4, 2004 when a 20-ton solid granite block from the Adirondack mountains in NY was laid in place by our crews “TO HONOR AND REMEMBER THOSE WHO LOST THEIR LIVES ON SEPTEMBER 11, 2001 AND AS A TRIBUTE TO THE ENDURING SPIRIT OF FREEDOM".

Innovative donated that granite block and some of our subcontractors involved in the process of shipping, cutting, polishing and setting the block also donated their services. A video of the cornerstone preparation and initial dedication by Governor Patacki is available on the Innovative Stone website. Initially planned as the first piece of the foundation of the building the cornerstone was eventually returned to Innovative in Hauppauge, Long Island when the plans for the reconstruction of the World Trade Center were revised.

In order to continue to honor the 9/11 heroes, Innovative Stone rededicated the monument at their headquarters in Hauppauge on September 11, 2009 in their newly constructed memorial garden. A second memorial ceremony was held at the Innovative Stone Headquarters this past week on September 8, 2010 to honor the 9/11 heroes. The memorial garden site and Freedom Stone is pictured below.

Tuesday, August 24, 2010

Adhered Thin Stone Wall Cladding Installations

As a Stone Consultant and Stone Contractor in Florida, and particularly South Florida over the past 30 years, I have observed many improper installations by local subcontractors. In particular, adhered stone installations for wall cladding using the spot bonding method (be it 4 spot, 6 spot, etc). Based on my experience any stone or tile adhered directly to the substrate should follow ANSI tile installation standards which require 80% coverage on the back of the tile for interior surfaces except showers which should be 95% and exteriors at 100% coverage.

In many cases even thick stone (3/4” or 1-1/4” thickness) has been installed using a variety of bonding mortars and also spot bonding methods but using no means of mechanical anchorage on interior walls as well as exterior walls. Many times the Owner, Architect or General Contractor are not aware of the proper installation methods and accept a low cost alternative to a mechanically anchored system.

Industry Installation Standards

MIA – Marble Institute of America - Dimension Stone Design Manual
ANSI – American National Standards Institute – Standards for Installation of Ceramic Tile
TCNA – Tile Council of North America Handbook for Ceramic Tile Installation

The MIA Design Manual recommends using only ¼” to ½” thick stone up to heights not to exceed 15’-0”. The size of the stone panels should not exceed 36” in the longest dimension or be more than 720 square inches in total area. The weight of each piece should not be more than 15 lbs. per sq. ft.

The MIA endorses the use of some of the installation methods detailed in the TCNA Handbook for Ceramic Tile Installation for installation of stone tile. The methods endorsed for wall tile installations are W201, W202, W211, W221, W222, W231, W241, W243 and W244E. For stone tile walls directly adhered to concrete or stable masonry surfaces with thinset mortar W202 is the required method. Please note that a waterproof membrane is required for all exterior installations. TCNA method W215 Spot-Bonding Epoxy for ceramic tile, is as of the date of this writing not endorsed in the MIA Design Manual for adhered stone. The TCNA refers to the epoxy manufacturers specifications for ceramic tile installation instructions using this method. Also of note, movement joints are always mandatory per Method EJ171, as detailed in the TCNA Handbook (see below).

Movement Joints - Vertical and Horizontal

Especially important to a successful adhered wall cladding installation are the placement of movement joints. The TCNA Handbook establishes the guidelines for movement joints as follows. Interior movement joints should be placed 20’ to 25’ in each direction. Exterior movement joints should be placed 8’ to 12’ in each direction. Also, interior tile work exposed to direct sunlight or moisture should be placed at 8’ to 12’ intervals in each direction. Please note, in areas where the stone tile is spanning different materials such as concrete columns or slab lines to adjoining masonry walls or other changes in backing materials, such as gypsum board, then a movement joint is also necessary. Basically, a soft joint should be located where any dissimilar materials meet since they have different rates of expansion and contraction as well as differing movement as a result of differential movement of the building structure.

Substrate Tolerances

When adhering directly to the backup substrate it is important to inspect for tolerances of the substrate and proper preparation by other trades. The MIA requires a more stringent tolerance for the backup substrate than the TCNA does for a ceramic tile installation. The MIA requires the backup to be within 1/8” in 10’-0” of the required plane for thinset stone veneer where the TCNA requires the backup to be within ¼” in 10’-0” for installation of ceramic tile in thinset mortar.

Joint Size

Another important consideration for an adhered stone tile installation is joint size. Optimum joint size should be considered relative to the size of the stone tile and the stone tile fabrication tolerances in order to mitigate the appearance of lippage. Lippage, an installation tolerance, will be covered in an upcoming Blog Post.

Typically, and in accordance with the MIA Design Manual guidelines, exterior stone wall cladding should have joints that are ¼” width minimum but 3/8” preferably. For larger size exterior wall panels ½” wide joints are frequently required depending on inherent warpage and stone fabrication tolerances. Interior stone wall cladding should have joints that are 1/16” minimum but preferably 1/8” in width depending on stone fabrication tolerances and inherent warpage. For large panel size units ¼” or larger width joints are required frequently. Tight, hand-butted joints should not be used under any circumstances.

Mesh Backing

Depending on the type of stone material used you may come across stone tile panels with fiberglass mesh reinforcement applied to the back side of the tile. This reinforcing mesh is embedded in an epoxy or polyester resin. This method of backing is generally used to reduce breakage and make handling safer when working with large slabs of fragile stone. However, please be aware that cementitious materials, such as thinset mortars, will not adhere properly to epoxy adhesives. Only compatible epoxy adhesives should be used that provide the required bonding strengths to the fiberglass and epoxy backing you are bonding to. It is interesting to note that a well known manufacturer of epoxy stone adhesive has specific requirements for removing any epoxy and mesh backing down to the bare stone where you will be using their adhesive to bond to the back of the tile. This should be done using a mechanical wheel grinder with a diamond blade before application of their epoxy stone adhesive.

Please let me know if you think this post was helpful and any other information you would like to share regarding your experiences.