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Home , Countertop, Granite

A Homeowner’s Guide to Natural Stone Installation Table of Contents

1. Introduction ...... 1 15. Maintenance ...... 10 2. Stone Materials ...... 1 (Application of Sealers; Topical Sealers; Impregnators; General Precautions; (Varieties: ; , Serpentines Care and Cleaning Practices) and Onyxes; ; and Travertines; Stone ) 16. Stone Swatches and Installations .....11 3. Communicating with Your Contractor ..2 17. Drawings (Documentation; You and Your Subcontractor’s RC-001 Responsibilities; Shop Drawings; Stone Layout ...... 13 Slab Layout) RC-002 4. Cabinet and Substrate Requirements..3 Kitchen Layout ...... 14 (Measurement Tolerances; Subtops; RC-003 Cabinet , End Panels and Hardware) Corner Joinery Examples ...... 15 5. Field Measurements ...... 3 RC-004 (Cabinet Components) Typical Joinery at Kitchen ...... 16 6. Design Considerations ...... 3 RC-005 (Joinery Layout (Seam Placement); Spans Detail of Rodding Reinforcement ...... 17 and Cantilevers; Sink Mounts; Edge Profiles; RC-006 Corner Embellishments; Backsplashes) Undermount Sink Support Details ...... 18 7. Quality Fabrication Methods ...... 4 RC-007 Support Details for Heavy (Finishing Edge Profiles; Cutouts for (Enameled Cast-Iron) ...... 19 Auxiliary Equipment) RC-008 8. Installation Methods ...... 5 Support Details for Rimmed or (Dry Assembly; Shims; Adhesive; Final “Drop-In” Sink Styles...... 20 Positioning and Filling; RC-009 Sealer Application) Vanity Top Details ...... 21 9. Tolerances...... 5 RC-010 (Joint (Seam) Widths; Lippage; Slab Thickness; Stone Shelf Details...... 22 Exposed Edges; Joints at Materials RC-011 Transition; Slab Flatness and Levelness) Cantilever Supports...... 23 10. Adhesives and Joint Fillers...... 6 RC-012 (Types; Seam Filler Materials) Edge Profile Nomenclature ...... 24 11. Stone Countertop Considerations ..7 (Subtops; Edge Treatment; Stone Tile Tolerances; Joint Widths; Vein Trend; Disclaimer Shading Variation; Splashes; Back This document is written as a general guideline. The Buttering; Tile Reinforcement) Institute of America and its Member companies have neither liability nor can they be responsible to any 12. Resin-Impregnated Slabs...... 8 person or entity for any misunderstanding, misuses, or (Description of Procedure; misappliation that would cause loss or damage of any Design Considerations) kind, including loss of rights, material, or personal injury, or alleged to be caused directly or indirectly 13. Reinforcement Techniques...... 8 by the information contained in this document. (Fiberglass Mesh; Liner Blocks; Splines; 28901 Clemens Road Rodding) Suite 100 Cleveland, OH 44145 14. Allowable Repair ...... 9 440.250.9222 (Fissures; Cracks; Chips; Pitting) www.marble-institute.com chemicals commonly found in a home; NATURAL STONE however, there may be trace present in some granites and -like COUNTERTOP stones that are vulnerable to some acids.

INSTALLATION Marbles, serpentines, and onyxes are traditionally prized for their aesthetic appeal, 1. INTRODUCTION accentuated by distinct veining and often The beauty and permanence of natural stone bold colors. They are relatively softer than are enjoyed by many. The full granite, although some serpentines are as potential of any installation is realized only dense as some granites. Marbles can be when the selection, design, fabrication, and scratched by kitchen utensils so it is best to installation are completed by, or with the use cutting boards and other protective consultation of, qualified and experienced measures. Use only non-abrasive products individuals. This document has been when cleaning marble. prepared and published by the Marble Institute of America to help guide consumers Marbles can also be etched by chemical through the process professional fabricators attack. These stones are calcium carbonate- use when using natural stone as a countertop based and are damaged by exposure to acidic surface. solutions such as lemon juice, tomatoes, vinegar, etc. The use of inappropriate cleaning agents may also trigger acidic attack. 2. STONE MATERIALS Acidic solutions can permanently etch the Varieties. Many varieties of natural stone surface of the material. The application of a have been used successfully for countertop sealer will reduce, but not eliminate, the surfaces. However, different types of stone vulnerability to acidic attack. For these have specific properties that offer advantages reasons, your stone dealer may not or disadvantages in various applications. The recommend marble for use in . following is a brief overview of the common varieties of stone used as countertops. Slates have high resistance to chemicals and

have been traditionally used as chemistry Granites are undoubtedly the most popular laboratory tops. However, slates are softer stone type used in countertop applications than granite and therefore vulnerable to today. This group of stones includes many scratching and abrasion. has a natural stone materials that are not true granites by cleft (not a smooth surface). Some suppliers geological definition. However, because their provide slate slabs that are not honed. Be properties are so similar, the American specific about the kind of finish you desire. Society for Testing and Materials The same precautions mentioned for marbles International (ASTM) lumps them together as with regard to damage should be applied to ‘granite’. These stones are known slates. geologically as , anorthosite, , , and , to name a few. Limestones and travertine are calcium Whatever the name, these stones are some of based similar to marble. Therefore, they have the hardest of the common countertop the same weaknesses as marbles when used as stones, offering high levels of resistance to countertops. Abrasion damage is a concern, abrasion and scratching. The primary particularly if the stone is polished. Many minerals in granite are resistant to almost all varieties of these stone types will absorb

© 2008 Marble Institute of America Page 1 water to some degree and must be sealed to are removed BEFORE installation. Also, help protect them. make sure that your installation date does not conflict with other work being done in your Stone tiles can be used as a countertop home ( floor finishing, tile installation, surface material. The finished surface will other tradesmen, etc). carry the same precautions as the particular stone type from which it is made. The joint Shop Drawings can effectively filler, whether , sealant, communicate exact cutting information to or resin, may have specific requirements for you. A shop drawing is a highly detailed protection and maintenance. Follow the document that will identify all aspects of the recommendations of the manufacturer of the finished product installation. The shop material. drawing is prepared by your fabricator, showing the layout of the stone pieces, 3. COMMUNICATING WITH YOUR location and size of all seams, and details CONTRACTOR clarifying all corner and edge treatment Documentation. As dictated by standard conditions. Some fabricators produce full size practices of good business, all templates that are highly detailed. These communications MUST be documented in detailed templates may be considered “full writing. size” shop drawings. Whatever the format, you will review and approve this document All natural stones are unique. Some have pits, prior to the start of fabrication. This is the fissures, cracks, corrosive minerals, or other time to ask questions about seam placement, features that you may find objectionable. cutouts, etc. These should be acknowledged and pointed out to you when samples and/or slabs are Stone Slab Layout. When working with being viewed. You need to be aware that highly variegated materials, insist that you some of these features may become more or participate in the layout of the actual stone less noticeable when the position (vertical or slabs. This is very important and highly horizontal) of the slab is changed, or when recommended so that you can fully the lighting intensity is changed. understand what can or cannot be done. Keep in mind that the pricing may You and Your Subcontractor’s change if you decide to have the stone cut in Responsibilities. installation, a certain way that causes unnecessary waste. plumbing rough-in, electrical rough-in, etc. are usually required to be completed by you, 4. CABINET AND SUBSTRATE or by subcontractors coordinated by you. REQUIREMENTS These should be specifically addressed in Cabinets and any trim that affects the overall writing. Your stone contractor will install size of the stone countertops must be your stone, not connect electricity or water. permanently installed in their final position prior to field measuring for countertops. Granite is heavy! Please have a clear path from your driveway to your kitchen so that Measurement Tolerances. Top surfaces installation crews can navigate through your of the stone cabinets must be within 1/8" (3 home easily. Please have walkways free of mm) of flat and level when measured across a ice, snow and clutter. Also, if you have distance of 10'- 0" (3 m). Wall surfaces to existing countertops, please make sure they receive stone backsplashes must be plumb

Page 2 © 2008 Marble Institute of America and within 1/8" (3 mm) of a true plane when positions. The following related components measured across a distance of 10'- 0" (3 m). must be available to the Technician at the When cabinets are not within these time of measurement (templating): tolerances, you (or your Authorized • Cabinet Doors Representative), will be asked for permission • End Panels to proceed with the installation. Installing • Cabinet Hardware cabinetry outside of these tolerances will require excessive shim spaces and wide • Sinks (and Manufacturer-supplied regions of filler material. Any necessary templates) aesthetic improvements to conceal this • Plumbing Fixtures condition (e.g., additional wood trim) may • Cook Tops be your responsibility. • Exhaust Vents (when full-height splash is required) Subtops. Fragile stone varieties may require • Electrical Outlets (roughed in) a full subtop to support the stone. Generally, • Refrigerators (in some cases) sound varieties of granites and marbles can be used in thicknesses of 20 mm (¾") or greater without the use of a subtop. However, the 6. DESIGN CONSIDERATIONS presence of aesthetically pleasing but Joinery Layout (Seam Placement). The unsound veins, cracks, or excessive fissuring layout of the joinery (seams) of the will mandate the use of a subtop, regardless countertops is extremely important to the of thickness. Appropriate materials for overall appearance upon completion. Details subtops are marine-grade plywood, exterior- on drawings RC-001, -002 and -003 show a grade plywood, waterproofed medium- variety of joinery schemes. Make sure you , or furring strips. understand where seams will be and how Excessive weight requirements, like that of a seams may affect the overall appearance of heavy cast-iron sink, may require the use of the stone. This is especially true when either a subtop or auxiliary framing to carry installing some of the higher-end varieties he weight of the sink and its contents. Water with obvious veins and movement. weighs around 8⅓ lbs. per gallon. Some of Spans and Cantilevers. In designs where the larger sinks can easily hold 10 gallons or part of the countertop is spanning between more. That’s an additional 83 pounds (or supports, the length of the span shall be more) hanging under your counter! limited to 2'- 0" (600 mm) for ¾" (20 mm)

stone thicknesses and 3'- 0" (900 mm) for Cabinet doors, end panels, and 1¼" (30 mm) stone thicknesses. In designs hardware must be installed before the field where the countertop is cantilevered or measurements are made. Upper cabinets are overhanging the supports, the cantilever shall usually required prior to installation if a full be limited to 6" (150 mm) for ¾" (20 mm) height backsplash is to be installed. If not, thick countertops and 10” (250 mm) for 1¼" then it is best to position them after the stone (30 mm) countertops, but in no case may the installation. cantilevered portion represent more than 1/3 of the width of the countertop. 5. FIELD MEASUREMENTS Cantilevered countertops exceeding these Cabinet Components. Field dimensions will require corbelled supports measurements are taken once all cabinets beneath the stone. The exposed underside of have been installed in their permanent cantilevered portions of countertops will be

© 2008 Marble Institute of America Page 3 sawn or otherwise unfinished surfaces. Note: Backsplashes are normally made of the same Fragile stones may require corbelled supports thickness as the countertop material. This for cantilevers that are less than those allows the Fabricator better yield from the specified. slabs, as the narrow strips will aid in the layout efficiency, and it also provides better Sink Mounts. Sinks are supplied in one of color match. Mixing materials of two several types: Top mount, (or self-rimming), different thicknesses requires using stone undermount, and “farm-home.” In the case of slabs sawn from two different blocks, and the top-mounted sinks, the weight of the sink color variation can be pronounced. and its contents are transferred to the top However, some Fabricators have the surface of the stone counter via the rim of the machinery to plane down backsplashes using sink. Undermount sinks can be anchored to the same slab or block of material to get a the underside of the stone countertop or thinner splash and match the rest of the carried by a subtop. A subtop or auxiliary counters. On stones with obvious veining, framing may be required for either design the vein of the splash should match the when more fragile stones are used, or when countertop below. the sink (with contents) is excessively heavy. Refer to details on drawings RC-008 through Backsplashes are not assumed to be part of RC-011 for examples of sink mounting. the job and must be specified if you want Note: cast iron sinks will always require the them. extra support stated above for both top and undermount types. 7. QUALITY FABRICATION

METHODS Edge profiles or silhouettes; add elegance Finishing Edge Profiles. Professionally to the finished project. Edge profiles with finished edge profiles will be a constant narrow projections and sharp corners are thickness and smooth along the entire length. more susceptible to chipping than those with Edges are finished to the same type and a larger, curved silhouette. Examples of edge quality of surface as the top, unless a profiles commonly used are included on contrasting edge surface has been specified drawing RC-016. With machinery and for accent purposes. When working with tooling available to modern fabrication shops, resin treated slabs, exact color match many custom profiles can be created which between the edge surface and the top surface are not shown here. Ask your fabricator if may not be achievable. you have something special in mind. Your selection of an edge detail will likely influence the Cutouts for auxiliary equipment must cost of your countertops more than any other conform to equipment templates, with decision you make. allowable tolerances. Please verify that the

equipment templates match the equipment Corner Embellishments. Corners of stone you are installing. There have been cases countertops can be cut square, cut to a where the supplied manufacturer templates radius, or projected. did not match the sink, cooktop, etc. In the

interest of safe handling, some cutouts may Backsplashes. Partial backsplashes usually be partially or completely performed in your range from 4" to 8" high. Full-height home after installing your stone. backsplashes cover the entire area between the countertop and the upper cabinets.

Page 4 © 2008 Marble Institute of America 8. INSTALLATION METHODS workmanship practices. Due to variations in Dry Assembly. At the project site, it is fabrication equipment and availability, recommended that all stone pieces be “dry these tolerances may not be achievable, or in assembled” in place to verify satisfactory fit some cases, closer tolerances may be prior to the application of adhesive. achievable. Therefore, for any particular project, you and your contractor may agree Shims are commonly employed to level the to tolerances that are more or less stringent stone countertops. Shim material may be than those listed here. Such agreements wood or plastic. Maximum spacing between should be documented in writing. Unless shims is 2'- 0" (600 mm). Alternatively, otherwise agreed, the tolerances listed here longer spacing between shims may be used if are acceptable guidelines. the stone is supported with a The tolerances in this section pertain to large noncompressible filler material (usually stone panel-type countertops only. epoxy or polyester resin). This practice is Tolerances for stone tile countertops are often referred to as “hard packing.” listed below, in Adhesives and Joint Fillers.

Adhesive. The stone countertops are Joint (seam) widths between two stone secured to the substrate with a nonstaining units should equal 1/16" (1.5 mm), with a adhesive. Common construction adhesives or tolerance of ±1/64" (±0.4 mm). In such silicone sealant are the most popular cases where a larger joint width has been materials used. specified, the tolerance is to be ±25% (± ¼) of the nominal joint width. Joint width does Final Positioning and Joint Filling. not include the dimension of an arris (a small Final positioning of the stone is done either chamfer, approximately 1/16” x 1/16”) on manually or with the aid of commercially the stone edge. When an arris is used, the available stone-alignment tools. Filling the perceived joint width may be greater than the seams is normally completed prior to final actual width due to the seam filler occupying positioning of the stone units, allowing the the width of the arris. filler material to extrude out of the joint as the stones are pulled into alignment. The Lippage. In the stone , the term stone surface may be masked to prevent “lippage” refers to the unevenness of the contact by the filler material.

Sealer Application. After the countertops are installed and the seams are filled, a sealer or impregnator may be applied. Refer to the Reinforcement Techniques section below for further discussion of these applications. Alternatively, some fabricators prefer to apply the sealer or impregnator in the fabrication shop prior to transporting the pieces to the project site. finished surfaces of two adjacent stone units. Due to the relatively tight seams used in 9. TOLERANCES countertop installations, even minor amounts The tolerances listed here are achieved using of lippage are noticeable. Lippage may be skilled tradesmen following standard industry unavoidable due to permanent warp in the

© 2008 Marble Institute of America Page 5 slab stock. There should be no detectable normally provide greater bond strength, lippage at the front or rear edge of the while elastomeric sealants will provide some countertop. Maximum allowable lippage at forgiveness for movement within the cabinet the center of the countertop is 1/32" (0.8 and subtop underneath. Excessive movement mm). See sketch that follows for of the substrate, regardless of the type of clarification. adhesive used, will result in the cracking of seams or the stone itself. Verify that the Slab Thickness. The thickness of the product used does not stain the stone stone slabs used in a given project shall material. not vary by more than 1/8" (3 mm) between the thickest and thinnest slabs. Seam Filler Materials. Seams in the stone countertop are usually filled to the level of Exposed edges of adjacent stone slabs must the top surface. The most common filler be matched in thickness and properly materials are polyester resin, epoxy resin, installed so that neither the top nor bottom elastomeric sealant, and grout. Elastomeric surface exceeds lippage tolerances. sealants can be made from , polyurethane, or acrylic bases. Joints at Materials Transition. Visible joints between stone and other materials 11. STONE TILE COUNTERTOP (e.g., cabinetry, gypsum wall board) shall be CONSIDERATIONS 1/8", with a tolerance of ±1/16" (±1.5 Subtops. Stone tile countertops must have a mm), and filled with a soft, elastic material. subtop made of minimum 3/4" exterior Exceptions to this would be the joint grade plywood or ½" cementitious backer between a full height backsplash and the board. Subtop must be flat to within 1/8” in underside of the upper cabinets, which is to 10'- 0". be a nominal ¼" with a tolerance of ±1/8" (±3 mm). Concealed joints between the Edge Treatment. Exposed edges of the stone and other construction materials (e.g., countertop may be finished by providing an stone-to-wall joint underneath the edge profile strip of stone, wood, or metal. backsplash) shall be sized to ensure a Where stone is employed, it is to be used as minimum of 1/8" (3 mm) of cover. an apron to the top surface stone, which limits stress on the countertop/apron joint. Slab Flatness and Levelness. Individual stone slabs are to be flat within 1/16" (1.5 Stone tile tolerances for all stone types mm) when measured with a 4'-0" (1.2 m) must be 1/32" (1 mm) in length, width, and straight edge. Finished countertop surfaces thickness. including multiple stones are to be both flat and level to 1/8" (3 mm) across 10'- 0" Joint Widths. Unless otherwise agreed, (3 m). joint widths for stone tile countertops must conform to the following: Stone-to-wall 10. ADHESIVES AND JOINT FILLERS joints must be 1/8" (3 mm) in width. Stone- Types. Adhesives used for stone installation to-stone joints must be 1/16" (1.5 mm) can be either standard construction adhesives minimum, 3/32" (2 mm) maximum, and or elastic sealants with strong bonding uniform from stone to stone. Stone-to- properties to both the stone and the cabinetry joints must be 1/8" (3 mm) in substrate. Construction adhesives will width.

Page 6 © 2008 Marble Institute of America Vein Trend. When using stone tiles with practice. The intent of this procedure is to fill obvious veining, all tiles shall be installed pits, cracks, and fissures of natural stones with the vein running in the same direction. with a glossy resin to enhance the appearance of the polished slab. When received, the Shading Variation. Stone tiles are subject resin treatment is usually easily detected by to processes different from viewing the raw edges of the slab. Evidence structural stone. There is great latitude in the of excess resin is usually visible on the edges acceptability of shaded stones. Ask the of the slab if the stone has been treated. Installers to lay out the stone for your inspection and approval. Description of Procedure. The process involves evenly applying the resin on the Splashes must be stone tile, minimum of 4" surface of the cleaned, sawn slab. This is high. frequently done in an automated process, although some suppliers will do this Back buttering of all stone tiles is manually. Depending on the equipment used, required. This technique applies a portion of the slab may be placed over a large vacuum the installation material to the back face of table to draw the resin deeper into the stone. the stone. It requires placement of one-half The resin is allowed to cure, which may or of the setting material in the case of thin-set may not be accelerated with heat application. , epoxy, or non water-soluble Once the resin has cured, the slab is polished. adhesive, or a lesser quantity of very rich The polishing grinds most of the resin from mortar in the case of Portland cement, to the the stone surface, so that it remains only in back of the stone, while the balance of the depressions and some inter-crystalline setting material is applied to the bed. regions of the slab. The amount of surface Application should be performed so that one area that remains as resin varies due to the pass is completed in a north-south direction, natural features of the material, but it is while the second pass is performed in an east- usually a fraction of one percent (1%). west direction, thus ensuring, as close as possible, 100% contact of the stone to the The resin used in this process is commonly an installation bed. epoxy, polyester, or acrylic based polymer. Design Considerations. While the intent Tile Reinforcement. A common of this process is to provide a cosmetically reinforcement for fragile stone tiles is to more attractive surface, you should be aware apply a fiberglass mesh to the back surface of of several characteristics of resined stone: the tile. The adhesive used in this application • Color. The resin application is commonly an epoxy or polyester resin. normally makes the color of the When this type of reinforcement is adhered stone somewhat darker than an to the tiles, the Installer must use a thin-set untreated slab. This becomes an issue material that will bond to the resin- when finishing the edges of the impregnated backer. Most often this will countertop, as the color of the edge require an epoxy-based, rather than a will be lighter in appearance than the Portland-based, thin-set compound. color of the face surface. Several products are marketed in the 12. RESIN-IMPREGNATED SLABS industry for darkening the edge, but The application of resin to the surfaces of none have been found to be stone slabs has become an ever-increasing universally successful.

© 2008 Marble Institute of America Page 7 • Interaction with Sealers. There Splines. Seams, particularly those between have been cases of incompatibility narrow stone pieces, are often put together between a given resin and fabricator- using a steel or key. applied sealer combination. This Commonly, a large washer is used as the usually results in a “cloudy” or spline key. The metal is fully encapsulated “blotchy” appearance after the sealer with polyester or epoxy resin and fitted to product has been applied. closely cut slots in the stone, similar to the • Structural Flaws. The resin “biscuit” joint reinforcements used in process can hide cracks or other woodworking. blemishes which are structurally influential features of the material. Rodding. A commonly seen method of Assessment of the structural countertop reinforcement is the technique worthiness of the material can be referred to as “rodding.” Rodding is made more difficult as a result. beneficial to narrow strips of stone material, such as those in front or behind sink or cook • UV Light Exposure. Nearly all of top cutouts. This technique requires a the resins currently in use are shallow kerf (a narrow cut or groove) in the vulnerable to color change or surface underside of the stone slab. The kerf is then degradation when exposed to closely fitted with a metal or fiberglass rod, ultraviolet light. These materials are which is then fully embedded in epoxy or therefore not suitable for exterior polyester resin. The rod has greater applications. resistance to bending than the stone and helps

prevent the stone from bowing. A strip of 13. REINFORCEMENT TECHNIQUES fiberglass mesh backing is often applied over As products of nature, stones have varying the rodded region for additional strength and behavioral properties. Stones of reinforcement. lesser soundness or stones that have had substantial areas removed from the slab (e.g., 14. ALLOWABLE REPAIR sink cutouts) will benefit from reinforcement Stone countertops in need of repair require by a variety of techniques. competent, experienced artisans to achieve

the desired results. Repairing stone is Fiberglass Mesh. A common permitted when the refurbished region is not reinforcement for stone slabs of limited in a structurally significant area of the soundness is to apply a fiberglass mesh to the countertop, and when it can be accomplished back surface of the slab. The fabricator skillfully so that the repair is consistent in completes this process in the shop. The color and texture with the rest of the slab. adhesive used in this application is commonly an epoxy or polyester resin. Fissures occur naturally in many stone

types. A fissure is defined by the American Liner Blocks. Although not frequently used Geological Institute as “an extensive crack, in stone countertop construction, a liner break, or in the , which may block of stone material can be adhered to the contain -bearing material.” The term underside of the stone slabs (when no subtop “fissure” is used commercially in the stone is used) to reinforce seams or other industry to describe a visible separation along vulnerable areas. The liner block need not be intercrystalline boundaries or the voids between of the same type of stone material as the mineral . This separation may start countertop.

Page 8 © 2008 Marble Institute of America and stop within the field of the stone or Pitting of the countertop surface, extend through an edge. A fissure differs particularly in granite material, is a from a crack in that it is a naturally occurring commonly seen characteristic on natural feature in the stone. stone. Granites are made up of several different minerals, each mineral having a Cracks occur in stones as a result of different hardness. Granites contain , mechanically induced stresses during , , , ferrous handling, fabrication, transport, or titanium oxides, and other mineral installation. When cracks are detected in slab combinations. On the Mohs Scale (see insert material prior to fabrication, the best method on page 7), are the hardest is to simply avoid them during the layout mineral, with a rating of 10. Quartz and process. In stones with lesser soundness have a hardness of 6.5 to 7 and are properties, this option may not be practical, very durable. Biotite (also known as ) on or possible. When working with such stones the other hand is very soft (2.5) and flakes it is common practice to repair cracks by easily. All true granites have biotite in their cementing them together with epoxy or composition. Because biotite is relatively soft polyester resin, either with or without dowel and flaky, the first few layers are removed reinforcement. Cracks that occur as a result during the polishing process, causing pits of handling-induced stresses are often more throughout the slab. Some granites have difficult to repair, as they commonly include more biotite throughout their composition chipping in addition to the crack. Repair is than others. The higher the biotite content of frequently performed by injection of a the stone, the more pits it will have. Most penetrating resin adhesive, which may be polished igneous rocks will have varying dyed to match the stone, and then rebuffing degrees of pits, depending on the amount of the area after curing of the resin. In many biotite, , and phlogopite in their cases, the entire stone must be repolished to composition. make the repair unnoticeable. If the repair is attempted but unsuccessful, the stone is to be The pits do not make the granite less durable replaced with a new piece. or otherwise inferior, and do not in themselves qualify the slab for replacement. Chips can occur in stones either as a result Pits are common in all granites and should be of sawing operations or handling and restraint expected when dealing with a natural, devices. Particularly in the igneous stone polished stone containing several types of varieties, the exiting portion of the minerals of varying hardness. It is usually best blade will create many small chips. A small to not attempt repair of pits, as most repair chamfer, called an arris, of approximately techniques will not cosmetically improve the 1/16" x 1/16" (1.5 x 1.5 mm) can be used countertop. to eliminate most of these small chips. The use of an arris will make the seam appear 15. MAINTENANCE wider than its actual dimension when filled. Application of Sealers. The application of Larger chips may be repaired with epoxy or a topical sealer or impregnator is a common polyester resin if the completed repair is step in decreasing the vulnerability of the consistent in color and texture with stone to stains. unrepaired areas of the slab. In many materials, the resin used in the repair will Topical sealers cure as a film on the stone appear more natural if it is not dyed. surface. Since the material is actually

© 2008 Marble Institute of America Page 9 covering the stone, the appearance of the and maintenance will keep it looking stone surface may be altered by the beautiful. Make sure you understand which application of this type of product. This methods are best for your particular stone material will provide somewhat of a countertop. Ask your fabricator for the MIA sacrificial layer over the stone, and will brochure Care & Cleaning for Natural Stone absorb most of the wear on the countertop. Surfaces. For more information visit Since the sealer is softer than the stone, http://www.usenaturalstone.com/care/ind normal use of the countertop will result in ex.cfm abrasion of the sealer surface and dictate reapplication to maintain the original luster of the surface. A properly applied topical sealer will normally reduce, although not eliminate, the vulnerability of calcareous stones to attack from mildly acidic solutions.

Impregnators will penetrate the stone and cure a few millimeters below the surface, residing in the microscopic spaces between the minerals in the stone. These products do not actually “seal” the stone, and are more correctly referred to as a repellent rather than a sealer. As such, they are formulated to prevent transmission of liquids, while allowing transmission of vapor (not unlike ‘breathable’ fibers). Since they reside below the actual surface of the stone, the change to the appearance of the stone surface is minimal. Impregnators will be either hydrophobic, in that they repel water-based fluids only, or oleophobic, repelling both oil and water-based fluids. The Manufacturer of the impregnator product will recommend a reapplication interval.

General Precautions. When any surface protection product is used, care must be taken to read and follow the Manufacturer’s written instructions accurately. This will provide the greatest benefit from the application and will guarantee safe handling of the product.

Care and cleaning practices. The natural stone you have purchased for your home or office is an investment that will give you many years of beautiful services.

Stone is a natural product and simple care

Page 10 © 2008 Marble Institute of America © 2008 Marble Institute of America Page 11 Page 12 © 2008 Marble Institute of America

Butterfly Green Granite Granite Countertops: #1 in Cleanability!

In a recent study, granite countertops A follow-up study evaluated the provided the greatest reduction in Reduction in Bacteria differences in cleanability of three bacteria counts of all materials After Washing & Rinsing: common unsealed natural stones tested! Six countertop surfaces Granite ...... 36,000 to 1 * used for countertop surfaces against were contaminated with E. coli Stainless Steel ...... 4,000 to 1 an . Overall, there bacteria, then washed and rinsed ...... 2,400 to 1 was no statistical difference in Tile ...... 900 to 1 using dish soap and “normal and Wood...... 500 to 1 reduction after wash and rinse for reasonable” cleaning practices. Plastic Laminate...... 285 to 1 any of the four surfaces.**

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Genuine Stone® and the Genuine Stone® seal are trademarks of the Natural Stone Council.

* Source: “The Reduction of E. Coli on Various Countertop Surfaces,” by Dr. O. Peter Snyder, Jr., Ph.D., of the Hospitality Institute of Technology and Management, March 1999. ** Source: “A Study of the Cleanability of Marble and Granite Countertop Materials,” by Dr. O. Peter Snyder, Jr., Ph.D., of the Hospitality Institute of Technology and Management, February 2006. The Marble Institute of America and its Member companies are not responsible for any use or misuse that causes damage of any kind, including loss of rights, materials, and personal injury alleged to be caused directly or indirectly by the information presented. About the MIA

For over sixty years, the Marble Institute of America has served as the authoritative source of information on standards of natural stone workmanship and practice and the suitable application of natural stone products. Membership in the association is worldwide and includes natural stone producers, exporters/importers, distributors/wholesalers, fabricators, finishers, installers, restoration/maintenance specialists and industry suppliers — all committed to the highest standards of workmanship and ethics. MIA publishes a monthly newsletter for members, markets a range of technical publications and consumer pamphlets on natural stone, sponsors business and technical meetings and seminars on industry-related topics, provides educational programming for architects and construction specification professionals, and conducts the “Rocky” Advertising Awards and the annual Pinnacle Awards competitions recognizing outstanding natural stone projects worldwide. MIA also sponsors an industry accreditation program for high quality fabricators and commercial installers. MIA is also a leading promoter of stone usage in the commercial and residential marketplaces. MIA produces a number of consumer materials on the use of natural stone and its proper care and maintenance and hosts an informative website for consumers at www.usenaturalstone.com.

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