Natural Stone Countertop Installation - A Homeowner's Guide to - Natural Stone Institute
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A Homeowner’s Guide to Natural Stone Countertop Installation
Table of Contents
1. Introduction ........................................1 15. Maintenance ......................................10
2. Stone Materials ...................................1 (Application of Sealers; Topical Sealers;
Impregnators; General Precautions;
(Varieties: Granites; Marbles, Serpentines
Care and Cleaning Practices)
and Onyxes; Slates; Limestones and
Travertines; Stone Tiles) 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 Kitchen Layout ......................................13
Slab Layout)
RC-002
4. Cabinet and Substrate Requirements..3 Kitchen Layout ......................................14
(Measurement Tolerances; Subtops; RC-003
Cabinet Doors, End Panels and Hardware) Corner Joinery Examples ......................15
5. Field Measurements ............................3 RC-004
(Cabinet Components) Typical Joinery at Kitchen Sink .............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
Auxiliary Equipment) (Enameled Cast-Iron) Sinks...................19
RC-008
8. Installation Methods ...........................5 Support Details for Rimmed or
(Dry Assembly; Shims; Adhesive; Final “Drop-In” Sink Styles........................20
Positioning and Joint 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
Transition; Slab Flatness and Levelness) RC-011
Cantilever Supports...............................23
10. Adhesives and Joint Fillers..................6 RC-012
(Types; Seam Filler Materials) Edge Profile Nomenclature ...................24
11. Stone Tile 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) Marble 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 minerals
present in some granites and granite-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
countertops 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 kitchens.
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. Slate 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 gabbro, anorthosite, gneiss,
diabase, and diorite, 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 (wood 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 grout, plastic sealant, epoxy 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. Cabinetry 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
density particle board, 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 stock 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 industry, 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 silicon,
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 AmericaVein 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 manufacturing 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.
mortar, 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 stainless steel 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 fracture in the rock, which may
block of stone material can be adhered to the
contain mineral-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 crystals. This separation may start
countertop.
Page 8 © 2008 Marble Institute of Americaand 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 quartz,
mechanically induced stresses during feldspars, biotite, amphibole, 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), diamonds 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 feldspar have a hardness of 6.5 to 7 and are
properties, this option may not be practical, very durable. Biotite (also known as mica) 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, muscovite, 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 diamond 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 9covering 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 engineered stone. Overall, there
bacteria, then washed and rinsed Concrete ........................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.**
www.marble-institute.com
®
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
education materials on the use of natural stone and its proper care
and maintenance and hosts an informative website for consumers
at www.usenaturalstone.com.
28901 Clemens Road, Suite 100
Cleveland, Ohio 44145 USA
440-250-9222
Fax 440-250-9223
www.marble-institute.com
All rights reserved. No part of this document may be reproduced
or transmitted in any form or by means electronic or mechanical,
including photocopy, recording, or by an information storage
and retrieval system, without permission from the Marble
Institute of America.
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