Glossary Terms

Grout joints 1/8" or larger are typically used for floors. Choosing a wider grout joint for a tumbled stone installation on a wall can intensify the rustic appeal. When grouting joints 1/8" or larger, typically a sanded grout is recommended. MAPEI Keracolor S and MAPEI Ultracolor Plus FA are considered to be sanded grouts. MAPEI Flexcolor CQ grout uses a special type of coated sand and can be used in most installations where a sanded grout is recommended.

Grout joints 1/8" or smaller are typically recommended for glossy wall tile, polished stone, glass tile, delicate glass tile and mixed material mosaics. Choosing a narrow grout joint on a floor with rectified-edge porcelain can help to achieve a more monolithic appearance. When grouting joints 1/8" or smaller, typically an unsanded grout such as MAPEI Keracolor U is recommended. However, MAPEI Flexcolor CQ grout uses a special type of coated sand and MAPEI Ultracolor Plus FA grout uses a unique fine aggregate. Therefore, MAPEI Flexcolor CQ and Ultracolor Plus FA grouts can be used in joints as small as 1/16" wide and with most installations where an unsanded grout is recommended. Still, a test is always recommended to confirm compatibility.

To complete the job, a flexible sealant such as MAPEI Keracaulk S, Keracaulk U or Mapesil T will be required in grout joints that are considered to be areas of movement. Areas of movement include changes of plane such as a tub/tile line or countertop/backsplash line or the corners of shower walls. In addition, it is a good idea to seal cement-based grouts such as MAPEI Keracolor S and Keracolor U with a high-quality sealer such as MAPEI UltraCare Penetrating Plus, Stone, Tile & Grout Sealer.

(Also see Trowel Sizes and Type and Size of Tile)

Taking the time to back-butter large tile can make all the difference in having a successful, long-lasting tile installation. Back-buttering is a process of spreading a thin coat of mortar on the back side of the tile with the flat side of the trowel in order to achieve required mortar coverage and proper bond. Back-buttering is generally recommended for tiles that are 15" or larger on any one side.

Back-buttering is also an essential step when installing clear and translucent glass tile, if the tile does not have an opaque coating on the back. The application of a void-free coat of a white mortar such as MAPEI Mosaic & Glass Tile Mortar on the back of the glass helps to ensure that the installation will have a consistent color and appearance.

Do not back-butter ceramic tile with curved surfaces such as chair rails and rounded, decorative listellos. Back-buttering these shapes can cause cracking.

A backsplash behind a sink on a bathroom wall can add an element of luxury to the room. A backsplash behind a stove can be a simple way of adding a personal touch to the kitchen. Either way, a backsplash is a great project for a first-time do it-yourselfer! MAPEI Flexcolor CQ has a natural-looking appearance and is an ideal choice with most installations of natural stone. The added stain resistance of MAPEI Flexcolor CQ will also help make kitchen maintenance a little easier. For optimum stain resistance, an epoxy-based grout such as MAPEI Kerapoxy CQ is recommended.

(Also see Shower Floors, Shower Walls and Tub Walls)

A bathroom remodel can increase the value of your home. With careful planning, you can complete some of the work yourself and save money.

Bathroom floors on second-story areas require special consideration. Tub overflows can result in damage to building materials and finishes on floors below. Applying a waterproofing membrane like MAPEI Mapelastic AquaDefense is an easy way to help contain excess water and protect lower floors from water damage.

Properly calculating your project’s total area helps ensure an accurate estimate of the materials needed. The shape of your project space may require combining multiple measurements. Follow the simple directions on our Calculating Total Area page to guide you through the process.

To complete the job, a flexible sealant such as MAPEI Keracaulk S or MAPEI Keracaulk U will be required in grout joints that are considered to be areas of movement. Areas of movement include changes of plane such as a tub/tile line, countertop/backsplash line, floor/wall line or the corners of shower walls.

(Also see Substrates)

Cement board is a good choice for most installations of tile and stone on shower walls, tub walls and floors. It is important to install cement board in strict accordance to the cement board manufacturer’s written instructions.

Floors: Installation instructions for cement board on floors typically include applying cement-based thin-set between the exterior-grade plywood and cement board. The cement board is then screwed into the plywood while the thin-set is fresh/wet. MAPEI recommends the use of MAPEI Large-Format Floor & Wall Tile Mortar or MAPEI Large Tile & Stone Mortar as thin-set under the cement board. If leveling is needed on interior cement board floors, MAPEI recommends the use of a pourable leveler such as MAPEI Self-Leveler Plus over the cement board. MAPEI Primer T should be used to prime the cement board before the use of a pourable leveler.

Walls: Installation instructions to treat corners and seams on cement board on walls typically include using a self-adhesive mesh tape and thin-set. MAPEI recommends the use of MAPEI Large-Format Floor & Wall Tile Mortar or MAPEI Large Tile & Stone Mortar in conjunction with mesh tape recommended by the cement board manufacturer.

Cement pavers are made by pouring concrete into a mold. They can vary in thickness from about 1" to 3" and typically resemble brick or natural stone.

Surface Preparation: Exterior concrete substrates that are not even should be corrected using a quality exterior concrete repair product.

Setting: MAPEI recommends MAPEI Uncoupling Membrane Mortar mixed with MAPEI Polymer Additive for setting the pavers over exterior concrete.

Grouting: Because cement pavers are commonly at least 1" thick, special considerations should be made when grouting. MAPEI Ultracolor Plus FA grout is recommended for grouting cement pavers. As an alternative method, grout joints can be partially filled with one of the setting mortars above, leaving 1/4" depth of the joint open for grouting. After 24 hours, pavers can be grouted using MAPEI Keracolor S or MAPEI Flexcolor CQ grouts.

(Also see Ceramic Wall Tile, Glossy Wall Tile and Porcelain)

Ceramic tile is made from clay. A glaze is applied to the top surface and then the tile is fired at a high temperature. The glaze creates the color and pattern of the tile. The durability of the glaze on ceramic tile can vary greatly. Check the PEI rating of the tile for glaze durability.

Ceramic tile is generally quite porous and therefore is generally not recommended in exterior freeze/thaw zones.

(Also see Ceramic and Glossy Wall Tile).

Ceramic wall tile is commonly used for kitchen backsplashes and tub walls. It is typically less than 12" in size. Because it is designed for use as wall tile, it is usually not well suited for floors as the glaze or finish of this tile is not typically resistant to scratching or wear from foot traffic. Check the PEI rating of the tile for glaze durability.

(Also see Substrates)

Drywall has a paper or water-resistant covering over a core that is made of gypsum. It is a common building material used to construct interior walls in dry areas. Drywall should be installed in strict accordance with the manufacturer’s instructions and local building codes. It is best suited for interior dry areas only, as some building codes restrict the use of drywall and do not permit it to be used for shower walls or tub walls.

Drywall seams are patched and filled with a gypsum-based patching compound commonly known as “wall mud.” Because gypsum and cement are not compatible, it is important to prime all drywall surfaces with a primer such as MAPEI Primer T prior to installing tile.

If drywall has been painted, it is best to cover it with cement board or remove and replace it with new drywall or new cement board.

(Also see Substrates, Rough Concrete, Smooth Concrete and Exterior Concrete Substrates) Concrete is made from a mixture of cement and aggregates. It is primarily used to construct substrates on floors. Because concrete is made from a mixture of cement and aggregates, it is very compatible with cement mortars for tile.

All concrete substrates should be clean, dry and free of dust, dirt, oil, grease, paint, tar, wax, soap, concrete curing compounds, concrete color stains, concrete sealers, clear coats, loosely bonded toppings, any primers that are not MAPEI brand, old adhesive residues (unless otherwise recommended by MAPEI), and any other substance that may prevent, reduce or affect adhesion or performance.

Because countertops are closer to eye level than floors, skillful craftsmanship is the key to a professional-looking installation. For this reason, it is a good idea to make all the tile cuts and place the tile in position without adhesive or mortar before installing – this is called dry-fitting. With a little extra time spent carefully measuring and planning the installation, you can create a terrific food preparation area that you will be proud of!

Choosing a stain-resistant grout such as MAPEI Flexcolor CQ will help make kitchen maintenance easier. For optimum stain resistance, an epoxy-based grout such as MAPEI Kerapoxy CQ is recommended.

(Also see Concrete and Exterior Concrete Substrates)

Hairline cracks (very thin cracks) will often occur in new concrete slabs due to shrinking and are not typically a cause for concern. However, all existing cracks should be examined, as certain types of cracks can be a sign of a more serious issue. When examining existing cracks, there are three main things to look for:

1. Is the crack flat or is one side of the crack higher than another?

2. Is the crack short in its length or does it span from one outside wall to another?

3. Is the crack old and has it become wider over time?

If the crack is flat, short in length or is old and has not moved, the application of a crack-isolation membrane like MAPEI Mapelastic AquaDefense is recommended. However, if the crack is not flat, if it spans the length of the structure or if it has become wider over time, an inspection by an experienced professional engineer is recommended in order to determine appropriate repair procedures.

(Also see Glass Tile)

Some glass tiles are quite sensitive to scratching, such as glass tiles that are made of soft glass and glass tiles that have an iridescent finish. These types of delicate glass tiles should only be grouted with an unsanded grout like MAPEI Keracolor U. Adding MAPEI Grout Maximizer to MAPEI Keracolor U will help to reduce the porosity of the grout and help to keep the grout clean.

Efflorescence is a chalky, white mineral deposit caused by soluble salts. These salts can come from many sources including such Portland cement-based products as concrete slabs, concrete and masonry walls, cement-based grouts, cement-based thin-set mortars and cement pavers. Well water that has a naturally high concentration of minerals can also cause efflorescence. In addition, home water softeners add minerals to the water, which can contribute to efflorescence.

An even substrate would mean that there are no major surface deviations, imperfections or irregularities such as bumps and depressions.

For example, holes left by the removal of carpet tack strips would cause a concrete substrate to be uneven.

(Also see Substrates)

In order to tile over existing ceramic tile, the tile should be lightly sanded and then cleaned. New ceramic porcelain tile or natural stone can then be installed with a polymer-modified cement-based mortar such as MAPEI Large-Format Floor & Wall Tile Mortar, MAPEI Large Tile & Stone Mortar or a two-part cement-based mortar and liquid additive such as MAPEI Uncoupling Membrane Mortar mixed with MAPEI Polymer Additive. Always use a white mortar for installations of new natural stone and clean the grout joints while the mortar is still soft in preparation for grouting.

Existing epoxy coatings on floors should be cleaned and primed with MAPEI ECO Prim Grip. New ceramic or porcelain tile can then be installed with a polymer-modified mortar such as MAPEI Large Tile & Stone Mortar.

(Also see Substrates)

Existing laminate material on countertops and backsplashes should be lightly sanded and cleaned. Ceramic or porcelain tile can then be installed using MAPEI Large Tile & Stone Mortar or a two-part cement-based mortar and liquid additive such as MAPEI Uncoupling Membrane Mortar mixed with MAPEI Polymer Additive. Natural stone can be installed using MAPEI Large Tile & Stone Mortar (white) or a two-part mortar such as MAPEI Mosaic & Glass Tile Mortar mixed with MAPEI Polymer Additive.

(Also see Substrates)

In order to tile over existing natural stone tile, the tile should be sanded and then cleaned in order to completely remove any sealers. Ceramic, porcelain tile or natural stone, can then be installed using a two-part mortar such as MAPEI Uncoupling Membrane Mortar mixed with MAPEI Polymer Additive.

Natural stone tile up to 15" in length and width can be installed using a two-part mortar such as MAPEI Mosaic & Glass Tile Mortar mixed with MAPEI Polymer Additive.

(Also see Substrates)

Existing non-cushioned residential sheet vinyl that is well bonded should be lightly sanded and cleaned. Then ceramic or porcelain tile can be installed using a two-part cement-based mortar and liquid additive such as MAPEI Uncoupling Membrane Mortar mixed with MAPEI Polymer Additive.

Note: MAPEI products are not recommended or warrantied over any substrate that contains asbestos.

(Also see Substrates)

In order to tile over existing porcelain tile, the tile should be cleaned. New ceramic or porcelain tile can then be installed using MAPEI Large-Format Floor & Wall Tile Mortar, MAPEI Large Tile & Stone Mortar or MAPEI Uncoupling Membrane Mortar mixed with MAPEI Polymer Additive.

Natural stone tile up to 15" in length and width can be installed using a two-part mortar such as MAPEI Mosaic & Glass Tile Mortar mixed with MAPEI Polymer Additive.

(Also see Substrates)

Existing VCT should be cleaned with a commercial wax stripper, neutralized with plenty of water and allowed to dry completely. Ceramic, porcelain tile or natural stone can then be installed using a polymer-modified cement-based mortar such as MAPEI Large-Format Floor & Wall Tile Mortar, MAPEI Large Tile & Stone Mortar, or a two-part cement-based mortar and liquid additive such as MAPEI Uncoupling Membrane Mortar mixed with MAPEI Polymer Additive. Always use a white mortar for installations of new natural stone and clean the grout joints while the mortar is still soft in preparation for grouting.

Note: MAPEI products are not recommended or warrantied over any substrate that contains asbestos.

(Also see Concrete and Other Exterior Substrates)

Tiling an exterior concrete patio can help transform a backyard into a fun outdoor living space for relaxing or entertaining. Exterior concrete substrates that are not even should be corrected using a quality exterior concrete repair product.

All exterior concrete substrates should be clean, dry and free of dust, dirt, oil, grease, paint, tar, wax, soap, concrete curing compounds, concrete color stains, concrete sealers, clear coats, loosely bonded toppings, any primers that are not MAPEI brand, old adhesive residues (unless otherwise recommended by MAPEI), and any other substance that may prevent, reduce or affect adhesion or performance.

Concrete patios, driveways and balconies should be sloped so that water drains off the area and no large puddles of water are left over after rain. When no slope is present, MAPEI recommends hiring a professional to create the required slope using an appropriate exterior-rated cement-based product.

(Also see Substrates)

Exterior-grade plywood is also known as exterior-glue plywood. Its crossply construction and water-resistant glue make exterior-grade plywood the industry’s best choice for tile installations over a wood substrate. Tile installations over plywood are limited to interior floors and countertops in dry areas only.

Floors: Exterior-grade plywood floors should consist of a double layer of plywood, glued and screwed together. Each layer should be a minimum of 5/8" or 3/4" thick, to equal a minimum of 1-1/4" total thickness. The floor should be very solid and stable with no deflection (bounce or movement). Any deflection issues should be corrected prior to installation. Plywood should be free of paint. If plywood has been painted, paint should be mechanically removed. Old flooring glue should be mechanically removed or may be scraped down to a thin residue (depending on the type of glue). Minor low spots in plywood can be corrected by filling these areas with a cement-based patching compound such as MAPEI Planipatch. If leveling is needed, MAPEI recommends the use of a pourable leveler such as MAPEI Self-Leveler Plus. MAPEI Primer T should be used to prime the plywood before the use of a pourable leveler.

All exterior grade plywood substrates should be clean, dry and free of dust, dirt, oil, grease, paint, tar, wax, clear coats, loosely bonded toppings, any primers that are not MAPEI brand, old adhesive residues (unless otherwise recommended by MAPEI), and any other substance that may prevent, reduce or affect adhesion or performance.

(Also see Exterior Concrete Substrates and Other Exterior Substrates)

As you look around the outside of your home, it’s easy to imagine the home-improvement possibilities, such as maybe creating the perfect spot for a quiet cup of coffee or even a weekend barbecue.

Outside areas also require special materials. If your project is outdoors, uncovered and located in a climate that experiences temperatures below 0⁰F, a two-part mortar such as MAPEI Uncoupling Membrane Mortar mixed with MAPEI Polymer Additive, is recommended. For regions that rarely experience below-zero temperatures, MAPEI Large-Format Floor & Wall Tile Mortar and MAPEI Large Tile & Stone Mortar are also good choices. It is also a good idea to consider the planned use of the area. For example, if you plan to use the space as an eating area, a stain-resistant grout such as MAPEI Flexcolor CQ is a great choice.

Field tiles are the tiles that are installed in the main or central area of the installation. They generally have cut edges as compared to trim tile that has rounded edges or rounded corners.

Tiling a fireplace can be a simple way to update the look of your living area. Because fireplaces are occasionally used as heat sources, special materials are needed for long-lasting installations.

Porcelain tile, ceramic tile, or porcelain/ceramic mosaic can be installed using MAPEI Rapid Setting Tile Mortar or a two-part mortar such as MAPEI Uncoupling Membrane Mortar mixed with MAPEI Polymer Additive.

Glass tile and mixed material mosaics can be installed using a two-part mortar such as MAPEI Mosaic & Glass Tile Mortar mixed with MAPEI Polymer Additive.

Natural stone tile up to 15" in length and width can be installed using a two-part mortar such as MAPEI Mosaic & Glass Tile Mortar mixed with MAPEI Polymer Additive.

A flat substrate means that the surface is consistently even across the horizontal plane.

For example, installation instructions for wood-look plank tile may state that the maximum allowable variation of the substrate is not more than 1/8" in 10 feet. This is a flatness requirement.

Note: It is possible to have a flat substrate that is not level.

Replacing old carpet on a floor with new tile is a great way to increase the value of your home. Tiling floors can take some time, so it is a good idea to break down the project into several stages.

Even before you begin to tile, it is important to determine if your substrate is suitable to receive a tile installation. All deficiencies must be corrected prior to beginning to install the tile.

It is critical to use the correct setting material and the correct trowel size for the tile that you have selected. When you are installing the tile on the floor, make sure that you check for proper mortar coverage by periodically lifting a couple of tiles and inspecting them for coverage. Mortar should cover the entire back of the tile without voids or trowel lines. Give yourself plenty of time for grouting – it’s often the most difficult and labor-intensive part of the installation.

(Also see Delicate Glass Tile)

Glass tile is made from pouring melted glass into molds or fusing pieces of glass together with heat.

Some glass tiles have unique backings or coatings and require special types of setting materials. Always follow the glass tile manufacturer’s written installation instructions.

For most installations of glass tile, MAPEI recommends Mosaic & Glass Tile Mortar. When installing glass tile in a pool or when installing glass tile over waterproofing membranes such as MAPEI Mapelastic AquaDefense, mix MAPEI Mosaic & Glass Tile Mortar with MAPEI Polymer Additive.

When grouting glass tile, use an unsanded grout such as MAPEI Keracolor U. If a sanded appearance is desired, a colored quartz (CQ) grout such as MAPEI Flexcolor CQ or Kerapoxy CQ can sometimes be used successfully, but a test panel should be grouted and inspected for unacceptable scratching before grouting. Delicate glass tile should only be grouted with an unsanded grout like MAPEI Keracolor U. Adding MAPEI Grout Maximizer to Keracolor U will help to reduce the porosity of the grout and help to keep the grout clean.

(Also see Ceramic Wall Tile)

Glossy wall tiles have shiny and delicate finishes. For this reason, an unsanded grout such as MAPEI Keracolor U is recommended. Adding MAPEI Grout Maximizer to Keracolor U will help to reduce the porosity of the grout and help to keep the grout clean. If a ready-to-use grout such as MAPEI Flexcolor CQ is selected, always test a spare piece of tile to confirm compatibility.

A grout float is a rectangular-shaped tool with a handle that is designed for filling joints between tiles with grout. It has a rubber bottom and a handle on top. Grout floats that have soft foam rubber bottoms work well for grouting with cement-based grouts such as MAPEI Keracolor S and MAPEI Keracolor U. Grout floats that have hard firm rubber bottoms are best for grouting with premixed grouts such as MAPEI Flexcolor CQ.

Grout joint widths are also an important factor in a successful tile installation. When choosing spacer size, consider the aesthetics of the installation, the type and size of tile, the edge style of the tile and the type of grout.

3/16" is a standard-size joint width. Wider joints may be needed with installations of very large tiles. Even installations of small tile require a minimum of 1/16" grout joint. Note: Installations with tiles tightly butted together (zero grout) are not recommended and will likely develop serious issues over time.

(Also see Stone)

Honed and tumbled stone can be great choices for backsplashes where a relaxed, rustic decor is preferred. Honed and tumbled stones should be sealed before grouting to prevent grout pigment from staining the surface of the stone. Use a stone sealer appropriate for the type of stone.

Honed natural stone has a matte, dull finish as opposed to the slick, shiny, reflective finish of polished stone. Honed stone is sanded only until a smooth finish is achieved.

Tumbled natural stone has an aged, worn look. Tumbled stone goes through a mechanical process that weathers the stone until a distressed look is achieved.

Intermittent is a term that is commonly used to describe water exposure that is occasional. This means that the water exposure is not constant or continuous, allowing the area to dry somewhat between periods of water exposure. Shower walls and shower floors are considered to be areas that have intermittent water exposure. On the other hand, a swimming pool would be considered to be constant and continuous water exposure, as this area is submerged.

Laundry rooms on second-story areas require special consideration. Water spillovers from clothes washers can result in damage to building materials and finishes on floors below. Applying a liquid waterproofing membrane like MAPEI Mapelastic AquaDefense is an easy way to help contain excess water and protect lower floors from water damage.

(Also see Leveling)

A level substrate is uniformly parallel to the earth’s horizon.

For example; a carpenter’s level (mason’s level) is commonly used to check the levelness of a substrate. When the bubble is precisely between the lines, it means that the substrate is level.

(Also see Even, Flat and Level)

An easy way to determine how much leveling is needed is to place a carpenter’s level on a long straight edge and then measure the space (depth) between the straight edge and the substrate. This will pinpoint the deep spots and help you to estimate the need for leveling in the lowest areas of the room.

A self-leveling underlayment such as MAPEI Self-Leveler Plus is a pourable product that helps correct a substrate that is out of level. Self-leveling underlayments require very structurally sound, solid and stable substrates. Because self-leveling underlayments have short working times, it is a good idea to have at least three people working together when pouring a self-leveler - one to mix the product, one to carry the buckets and pour out the self-leveler, and one to spread the self-leveler, and guide it into the desired areas as it is poured.

Additional preparations could be necessary based on load/deflection. Refer to the TDS* for complete instructions prior to the start of the project. You can also call the technical service advisors at 1-800-992-6273.

A primer such as MAPEI Primer T is always required when using MAPEI Self-Leveler Plus.

(Also see Waterproofing)

A liquid waterproofing membrane such as MAPEI Mapelastic AquaDefense can often be used as a replacement for a PVC liner. When using a liquid waterproofing membrane such as Mapelastic AquaDefense, it is important to follow all instructions on the label and Technical Data Sheet as well as local building codes.

Note: Premixed adhesives like MAPEI Type 1 mastic and premixed mortars like MAPEI Premium Mortar for tile and stone should never be used over liquid waterproofing membranes.

(Also see Substrates)

Masonry substrates include brick and concrete block walls. Use a rapid-setting tile mortar such as MAPEI Rapid Setting Tile Mortar to fill recessed mortar joints in brick installations prior to installing tile.

All masonry substrates should be clean, dry and free of dust, dirt, oil, grease, paint, soap, clear coats, any primers that are not MAPEI brand, old adhesive residues (unless otherwise recommended by MAPEI), and any other substance that may prevent, reduce or affect adhesion or performance.

(Also see Mosaics)

Mixed material mosaics (mixed media mosaics) include combinations of small glass, stone and/or metal tile. When installing mixed material mosaics, MAPEI Mosaic & Glass Tile Mortar mixed with MAPEI Polymer Additive is recommended. Always follow the mosaic tile manufacturer’s written installation instructions.

When grouting mixed material mosaics, use an unsanded grout such as MAPEI Keracolor U. Adding MAPEI Grout Maximizer to Keracolor U will help to reduce the porosity of the grout and help to keep the grout clean. If a sanded appearance is desired, a colored quartz (CQ) grout such as MAPEI Flexcolor CQ can sometimes be used successfully, but a test panel should be grouted and inspected for unacceptable scratching before grouting.

It may be necessary to pre-seal any honed or tumbled stones in the mosaic before grouting to prevent grout pigment from staining the surface of the stone. Use a stone sealer appropriate for the type of stone in the mosaic.

(Also see Mixed Material Mosaics)

Mosaic tiles can be made of glass, delicate glass, porcelain, ceramic, polished stone or honed stone as well as a variety of other natural and man-made materials.

Mosaic tiles are very small or tiny tiles – usually about 1" x 1" in size. They can be sold individually for artistic applications, but they are more typically sold in sheets where each small tile is adhered to a mesh backing. The actual size of the tile refers to the average size of each individual tile – not the size of the sheet. When setting the mosaic sheets, leave a space between each sheet that matches the width of the space between the individual mosaic tiles. This will help to achieve a clean, uniform look.

A mud bed (mortar bed) is used to create the slope on the shower floor. A sand-and-cement mix such as MAPEI 4 to 1 Mud Bed Mix can be used as the material for the mud bed. When this type of sand-and-cement mix is mixed with water, it is called a dry pack. The dry pack should be the consistency of wet beach sand, just as you would use to make a sand castle with molded plastic beach toy. This consistency allows you to shape the mix precisely to the required slope.

(Also see Substrates and Exterior Concrete Substrates)

Exterior substrates have entirely different performance requirements than interior substrates. They must be able to withstand exposure to various weather elements and outside conditions and still remain structurally sound, solid and stable.

All exterior substrates should be clean, dry and free of dust, dirt, oil, grease, paint, tar, wax, soap, sealers, clear coats, loosely bonded toppings, any primers that are not MAPEI brand, old adhesive residues (unless otherwise recommended by MAPEI), and any other substance that may prevent, reduce or affect adhesion or performance.

Uncovered wood decking that is not over living spaces or storage areas should be covered over with a layer of exterior-grade plywood with a thickness of 5/8" or 3/4", followed by cement board and a liquid-applied waterproofing membrane such as MAPEI’s Mapelastic AquaDefense.

If you’re looking to convert your roof into a usable space, most roofing membranes are not designed to receive a direct bond of tile. The roofing membrane must first be covered with a mud bed (mortar bed) that has a proper slope and then covered with a secondary waterproofing membrane such as Mapelastic AquaDefense. MAPEI recommends hiring a professional when tiling over roofing areas. It’s a complex and technically advanced process that requires the skills of a knowledgeable and experienced installer. In addition, building codes vary between regions, so it’s important for your contractor to know the local codes and comply with all requirements. Note: Never nail or screw into a roofing membrane.

(Also see Leveling)

Interior concrete and exterior-grade plywood substrates on floors that have occasional low spots (about the size of a puddle or bird bath) should be patched and filled with a cement-based patching compound such as MAPEI Planipatch.

(Also see Mosaics and Stone)

Pebble stone and river rock mosaics have become fashionable choices for bathrooms. They are especially popular in water-front vacation homes. However, there are some important installation requirements to keep in mind when choosing pebble stone for a shower floor.

Polished natural stone has a shiny, reflective finish as opposed to the matte, dull finish of honed stone. Polished stone is sanded with finer and finer grades of sandpaper until a glossy finish is achieved.

When grouting polished natural stone, use an unsanded grout such as MAPEI Keracolor U. Adding MAPEI Grout Maximizer to MAPEI Keracolor U will help to reduce the porosity of the grout and help to keep the grout clean. If a sanded appearance is desired, a colored quartz (CQ) grout such as MAPEI Flexcolor CQ can sometimes be used successfully, but a test panel should be grouted and inspected for unacceptable scratching before grouting.

(Also see Ceramic)

Porcelain tile is made from high-quality clay and fired at an extremely high temperature. It can be glazed or unglazed. With unglazed porcelain tile, the color of the tile is the same from top to bottom – this is called through-body porcelain tile. Unglazed porcelain tile is sometimes polished like marble to achieve a shiny, reflective finish. With glazed porcelain tile, a glaze is applied to the top surface and then the tile is fired. The glaze creates the color and pattern of the tile. The durability of the glaze on porcelain tile can vary greatly. Check the PEI rating of the tile for durability. Sometimes porcelain tile is cut a second time after it is fired in order to achieve a perfect square edge. This type of porcelain is called rectified-edge porcelain.

Porcelain tile is generally considered to be impervious (non-porous) and therefore is highly recommended in exterior freeze/thaw zones.

(Also see Shower Floors)

A pre-formed base eliminates the challenging and time-consuming task of creating a slope with a mud bed. A Shower Base can be custom-ordered to fit a variety of dimensions and drain locations.

(Also see Waterproofing and Liquid Waterproofing Membranes)

A PVC liner is a vinyl waterproofing membrane that comes in a sheet and is placed over the pre-slope on a shower floor. The pre-slope is the first layer of the mortar bed (mud bed). The PVC liner is then topped with a second layer of mortar to create the main slope.

(Also see Concrete, Smooth Concrete and Exterior Concrete Substrates) Rough concrete will have a surface texture like sandpaper. This type of concrete is typically very porous and requires minimal preparation.

All concrete substrates should be clean, dry and free of dust, dirt, oil, grease, paint, tar, wax, soap, concrete curing compounds, concrete color stains, concrete sealers, clear coats, loosely bonded toppings, any primers that are not MAPEI brand, old adhesive residues (unless otherwise recommended by MAPEI), and any other substance that may prevent, reduce or affect adhesion or performance.

(Also see Pre-Formed Base, Waterproofing and Liquid Waterproofing Membrane)

Tiling a shower floor is an advanced-level installation project. So, it is a good idea to break down the project into several stages and then spread out the stages according to your experience, physical ability and skill level.

Remember: Proper waterproofing and slope are the most important steps of any shower floor project and are essential to a long-lasting installation.

(Also see Tub Walls)

Tiling walls in an individual shower is an intermediate level installation project. The more time that is spent in design, preparation and planning, the easier your installation will be. Also remember the rule: Measure twice and cut once. It may be helpful to plan the tile placement by creating a story pole. To make a story pole, first lay out the tile with spacers in between each tile on a flat surface, which will represent your tiled wall (left to right = bottom to top). Then mark all tile and grout joint measurements on a long wooden dowel rod. Transfer the markings onto your wall surface and review the placement.

Choosing polished stone for shower walls can transform a plain, boring shower into a place of extraordinary beauty. Because much of the stone will be in close range or at eye level, the color and uniqueness of the stone can truly be appreciated, so it makes sense to splurge in this application.

Set your first row of stone tile and allow the area to dry until the mortar achieves its initial cure and the stone tile becomes solidly bonded. Then build the stone tile upward toward the ceiling. Place plenty of spacers between the stone tiles to help keep the tiles in position until the mortar reaches its initial set. Use white, non-sag mortars such as MAPEI Large-Format Floor & Wall Tile Mortar (white) or MAPEI Large Tile & Stone Mortar (white) to help keep the tile from slipping downwards. An unsanded grout like MAPEI Keracolor U is typically recommended. Adding MAPEI Grout Maximizer to Keracolor U will help to reduce the porosity of the grout and help to keep the grout clean. Sealing both the grout and stone with a quality sealer will help to maintain the installation, keep it clean and reduce staining.

(Also see Mud Bed)

The slope (pitch) is the gradual descent in the angle of the shower floor. Slope is an essential component in shower floor construction because it guides the flow of water towards the drain. A sand-and-cement mix such as MAPEI 4 to 1 Mud Bed Mix typically serves as the material for the mud bed, which is used to create the slope on the shower floor.

Slope is also a critical component in successful exterior installations. It is very important for rain water to quickly drain off patios and balconies. If water remains stagnant, severe efflorescence issues can occur. When the flow of water is not moving away from the home, it can also increase the chance of moisture entering the home, which can create more serious issues.

Note: The industry standard for shower slopes is a range of 1/4" to 1/2" per foot. With certain installations such as ADA barrier-free showers and standard shower stalls with three-dimensional pebble tile and river rock mosaics, the minimum 1/4" per foot slope may be insufficient. A steeper slope may be required in order to facilitate good drainage.

(Also see Rough Concrete, Concrete and Exterior Concrete Substrates)

Smooth concrete will have a surface texture like a laminate countertop. Smooth concrete surfaces should be tested to confirm porosity. If the concrete absorbs water, then it is considered to be porous. Smooth, porous concrete surfaces should be mechanically abraded. Ceramic, porcelain tile or natural stone can then be installed with a polymer-modified cement-based mortar such as MAPEI Large-Format Floor & Wall Tile Mortar, MAPEI Large Tile & Stone Mortar or MAPEI Uncoupling Membrane Mortar mixed with MAPEI Polymer Additive. Always use a white mortar for installations of new natural stone and clean the grout joints while the mortar is still soft in preparation for grouting.

All concrete substrates should be clean, dry and free of dust, dirt, oil, grease, paint, tar, wax, soap, concrete curing compounds, concrete color stains, concrete sealers, clear coats, loosely bonded toppings, any primers that are not MAPEI brand, old adhesive residues (unless otherwise recommended by MAPEI), and any other substance that may prevent, reduce or affect adhesion or performance.

(Also see Honed & Tumbled Stone, Polished Stone and Pebble Tile & River Rock Mosaics)

Natural stone is a product of nature and includes granite, marble, travertine, slate, limestone, onyx, pebble tile and river rock. Polished Stone will have a slick, shiny, reflective surface. Honed & Tumbled Stone will have a matte, dull finish and may also contain deep voids and pitted areas. All stone should be pre-sealed before grouting to prevent grout pigment from permanently staining the surface of the stone.

The three main terms used to describe the required strength of an existing or newly installed substrate are: structurally sound, solid and stable. Structurally sound is a common construction term that indicates that a material is strong, sturdy and well-made. Solid is a general term that describes a material as being dense and free from damage and defects. Stable refers to the material as being firmly supported, securely fastened and inflexible.

Submerged indicates an area that is under completely under water. Tile that is on or below a swimming pool waterline is considered to be submerged. On the other hand, a shower floor would be considered to be intermittent, as this area only has occasional water exposure.

(Also see Type of Substrate, Exterior Concrete Substrates and Other Exterior Substrates)

The substrate is the basis for the tile assembly. Professional tile installers will tell you that a tile installation is only as good as what it is bonded to. So, before planning a tile project, it is important to determine if your substrate is acceptable to receive an interior tile installation.

If your substrate is not structurally sound, solid and stable, it is recommended that you replace it with an appropriate material.

All interior substrates should be clean, dry and free of dust, dirt, oil, grease, paint, tar, wax, soap, concrete curing compounds, concrete color stains, concrete sealers, clear coats, loosely bonded toppings, any primers that are not MAPEI brand, old adhesive residues (unless otherwise recommended by MAPEI), and any other substance that may prevent, reduce or affect adhesion or performance.

(Also see Type and Size of Tile)

Today's tiles come in a variety of types, sizes and shapes, and there are thousands of different tiles on the market to meet a wide assortment of tastes, budgets and styles. When selecting a tile, consider that the tile will look different when it is installed next to other tiles and it is grouted. For this reason, it is always a good idea to create a sample board (mock-up) with the tile and grout that has been selected.

Many factors should be considered when selecting the right trowel size for a tile installation, but the most important factor is the tile size. As a general rule, after tile is pressed into mortar, mortar should cover the entire back surface of the tile without voids or trowel lines. So, take time to check for proper mortar coverage by periodically lifting a couple of tiles and inspecting them for coverage. If there are voids or trowel lines showing, a larger-sized trowel may be required for the installation. Back-buttering is generally recommended for tiles with any side 15" or greater. Installations of tiles larger than 24" x 24" typically require the skill of a knowledgeable and experienced tile installer. The Technical Data Sheet and product packaging will provide mortar coverage for common trowel sizes.

Note: When using premixed products such as MAPEI Type 1 or MAPEI Premium Mortar for tile and stone, using a larger trowel can greatly extend the drying time of the mortar or adhesive.

(Also see Shower Walls)

Tiling a wall above a bathtub can help turn an outdated bathroom, into a fresh and renewed space in your home.

For a beginner-level installation project, choose small ceramic wall tile such as 3" x 6" subway tile with lugs (lugs are like built-in spacers that allow tiles to be placed tightly together with a predetermined small joint for grout.) A premixed tile adhesive such as MAPEI Type 1 mastic or MAPEI Premium Mortar for tile and stone works well for small ceramic wall tile over cement board. Using a premixed grout such as MAPEI Flexcolor CQ adds additional convenience and simplicity to the installation. If you decide to add a layer of waterproofing over the cement board, then you will need to use a polymer-modified cement-based mortar.

If you are an experienced installer, selecting a large 12" x 24" porcelain tile for tub walls will create a sleek, contemporary appeal. MAPEI Large-Format Floor & Wall Tile Mortar and MAPEI Large Tile & Stone Mortar are recommended for large and heavy tiles on walls. MAPEI Ultracolor Plus FA is a good choice when grouting large tiles. An epoxy grout such as Kerapoxy CQ is the best choice for wet areas and is also the easiest to maintain.

Glass or mixed material mosaic tile on walls above a bathtub can turn a drab bathroom into a sparkling retreat. Adding a layer of waterproofing over the cement board such as MAPEI Mapelastic AquaDefense will extend the life of the installation. MAPEI Mosaic & Glass Tile Mortar mixed with MAPEI Polymer Additive is the proper setting material for glass or mixed material mosaic tile over Mapelastic AquaDefense waterproofing membrane. An unsanded grout like MAPEI Keracolor U is typically recommended. Adding MAPEI Grout Maximizer to Keracolor U will help to reduce the porosity of the grout, help to keep the grout clean and reduce staining.

(Also see Tile)

There are many different materials used to manufacture tile. The most common types are: ceramic, porcelain and natural stone.

Some of the factors to consider when selecting the type of tile for your project are: color, pattern, edge style, shiny or matte surface, durability of finish, glazed or solid surface, slip resistance and of course price.

The size of the tile is determined by the measurements of its width and length. When you are asked for tile size, it is important to refer to the longest side of the tile. This will help you to select the mortar or adhesive that is appropriate for your tile, to purchase the correct amount of material and to use the right trowel size.

For example: Many wood look plank tiles are 6" wide by 24" or longer. So, the mortar that is selected for this installation should be recommended for a tile that over 15" long such as MAPEI Large-Format Floor & Wall Tile Mortar or MAPEI Uncoupling Membrane Mortar mixed with MAPEI Polymer Additive. In addition, the trowel that is used to spread the mortar should be appropriate for a tile that is over 15" in length.

(Also see Substrates)

There are many different materials used in home construction today. However, only a handful of these materials are suitable as substrates for tile installations.

The most commonly recommended substrates for interior tile installations are: cement board, exterior-grade plywood (floors only), masonry (walls), drywall and concrete. Existing finishes such as ceramic tile, porcelain tile, natural stone, laminate (countertops), VCT or well-adhered non-cushioned residential sheet vinyl can also sometimes serve as suitable interior substrates.

(Also see Liquid Waterproofing Membranes)

The main purpose of waterproofing is to prevent the intrusion of water and moisture in unwanted areas. All shower floors must have waterproofing.

Waterproofing is also an important step in installations such as second-story bathrooms and laundry rooms where excess water and moisture may occur.

MAPEI recommends Mapelastic AquaDefense for most areas where waterproofing is required.