Shower Floors

1. Determine if the type of substrate is acceptable to receive a shower floor installation. It must be structurally sound, solid and stable.
2. When appropriate, replace it with an appropriate substrate material.
3. Clean the substrate. All 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.

1. If you are using a pre-formed base, read all shower-base instructions before beginning. Go to Step 3.
2. If you have chosen to use a traditional mud bed method, MAPEI recommends that you hire a professional for this part of the shower floor project. Creating a pitch with a sand/cement mix is a complicated process that requires the skill of an advanced-level installer.

Note: It is critically important to obtain the correct slope in order to avoid standing water. The correct application of the waterproofing membrane is equally as important and is essential to a long-lasting shower floor.

1. If you are using a pre-formed base, follow the manufacturer’s written installation instructions. Go to Step 4.
2. If you have decided not to use a pre-formed base, MAPEI recommends that you hire a professional to construct the slope and apply the waterproofing for you.

1. Measure and mark the center points of two opposite walls. Use a chalk line tool, china marker or pencil to create a line that connects the two points.
2. Measure and mark the center points of the two remaining walls. Create a line connecting these points. The intersection of the two lines marks the center point of the shower floor.
3. Check that lines are square by using a framing square and adjust as needed.
4. If you are using border tiles or decorative accent tiles, measure and mark lines to indicate these areas.
5. Dry-fit a row of tiles (or mosaic tile sheets) by placing the tile (or sheets) in position with spacers along reference lines to check for accuracy and determine tile cuts. Adjust reference lines as needed.
6. Take time to carefully plan your layout.
7. Dry-fit all field tiles as well as border and decorative accent tiles.
8. Pre-cut all tiles.

1. Measure water amounts carefully. Mix the mortar according to the instructions on the package. Refer to current Technical Data Sheets on our product pages for detailed instructions.
2. Select a notched trowel size that is appropriate for the size of the tile. Contact MAPEI’s Technical Services Department for guidance if needed.
3. Using a notched trowel, spread mortar while holding the trowel at a 45-degree angle to the shower floor.
4. First, using the straight (flat) side of the trowel, apply a thin, even coat to the surface. Follow immediately with more mortar and “comb” the mortar in one direction, using the notched side of the trowel to achieve an even-setting bed. If tiles larger than 15″ (38 cm) are used on any side, back-butter tiles before setting tile to provide uniform mortar coverage and maximum support.
5. Only spread as much mortar as can be covered with tiles before the mortar skins over or loses transfer when touched.

Note: If using mesh-backed mosaic tile sheets, skip Step 6 and go to Step 7.

1. Place the first field tile at the intersection of the layout lines, making sure the tile is properly aligned with both layout lines.
2. Continue to place field tiles in position on the substrate and firmly apply pressure to the face of the tiles while moving the tiles back and forth perpendicular to the trowel ridges.
3. This helps to ensure that the mortar transfers to the back of the tiles and that the tiles are in an even plane with adjacent tiles.
4. Check several of the set tiles for adequate mortar coverage by lifting them up. All of the ridges should be collapsed without voids or trowel lines. Mortar should also cover the entire back of the tile without voids or trowel lines.
5. Keep a damp sponge nearby for quick cleanup in case mortar is dropped on the tiles or any other surfaces.
6. Keep grout joints free of mortar.
7. Place plenty of spacers in between tiles to ensure even spacing between tiles and straight, uniform grout joints.
8. Allow field tiles to dry to a firm set and then install border tile and decorative accent tile. Refer to the instructions on the package of mortar or current Technical Data Sheets on our product pages for recommended drying times.
9. Protect the area from use and avoid walking on the tile.
10. (Go to Step 8.)

Note: Follow the written instructions of the mosaic tile manufacturer when instructions are provided.

1. Gently place the first mosaic tile sheet at the intersection of the layout lines, making sure the sheet is properly aligned with both layout lines.
2. Continue to gently place sheets in position on the substrate.
3. Using a soft foam rubber grout float, place the float flat against the top surface of the sheet and apply gentle pressure. This will ensure that the mortar transfers to the back of the mosaic tile and that the tile is in an even plane with the adjacent mosaic tile sheets. Avoid pushing too hard, which will result in mortar coming upward and filling the grout joints.
4. Check several of the set mosaic tile sheets for adequate mortar coverage by lifting them up. All of the ridges should be collapsed without voids or trowel lines. Mortar should also cover the entire back of each individual tile without voids or trowel lines. Note: This is especially important for clear and translucent glass tile .
5. Keep a damp sponge nearby for quick cleanup in case mortar is dropped on the tiles or any other surfaces.
6. Keep grout joints free of mortar.
7. Place plenty of spacers in between mosaic tile sheets to ensure even spacing between tiles and straight, uniform grout joints.
8. Allow mosaic tile sheets to dry to a firm set and then install border tile. Refer to the instructions on the package of mortar or current Technical Data Sheets on our product pages for recommended drying times.
9. Protect the area from use and avoid walking on the tile.

1. Allow tiles to dry until a firm set. Refer to the instructions on the package or current Technical Data Sheets on our product pages for recommended drying times.
2. Remove the spacers.
3. Certain types of tiles – such as heavily pitted tiles, unglazed tiles, and tiles that have textured surfaces such as some wood look tiles – may require special preparation before grouting. The application of a pre-grouting sealer may be necessary to prevent grout haze and permanent staining of the tile.

1. Moisten the surface of the tile with a damp sponge.
2. If Keracolor U Unsanded Grout, Keracolor S Sanded Grout or Ultracolor^® Plus FA grout is used, measure water amounts and do not add any extra water. Mix the grout according to the instructions on the package. Refer to current Technical Data Sheets on our product pages for detailed instructions.
3. If MAPEI’s UltraCare^® Grout Maximizer additive is used with Keracolor U Unsanded Grout or Keracolor S Sanded Grout, mix the entire bag of grout with ¾ (75%) of the coordinating unit of UltraCare Grout Maximizer and do not add any water. Add some or all of the reserved UltraCare Grout Maximizer as needed in order to reach a sticky paste consistency similar to creamy peanut butter.
4. Next, holding the grout float at a 45-degree angle, force grout into the joints to completely fill the joints without voids.
5. When grouting a large area, grout and clean one section at a time rather than applying grout over the entire tile area.
6. Remove excess grout from the tile surface by moving the rubber float at a 90-degree angle across the tile in a diagonal direction.

1. Refer to the instructions on the grout package or current Technical Data Sheets on our product pages for cleaning instructions.
2. Never allow the grout to remain on the surface of the tiles for an extended length of time before completing the initial cleaning.
3. After each wipedown, rinse and wring out the sponge so that no excess water stays on the tile surface.
4. Change the rinse water frequently. Having multiple buckets of clean water at hand will simplify this process.
5. Make sure that all tiles are thoroughly cleaned before the grout dries. Note: This is especially important when using a rapid-setting cement-based grout such as MAPEI Ultracolor Plus FA.
6. If grouting with MAPEI Keracolor S Sanded Grout or MAPEI Keracolor U Unsanded Grout, come back about an hour later and check the tile for any residual haze. If needed, buff the tiles with a dry terrycloth towel to remove any remaining haze. Contact MAPEI’s Technical Services Department if the grout haze persists.
7. If using MAPEI Flexcolor^® CQ grout, perform a second wash and use a light-duty scrubpad (the kind that is safe for china) to remove any remaining haze. Contact MAPEI’s Technical Services Department if the grout haze persists.
8. If grouting with MAPEI Ultracolor Plus FA, all residual grout haze must be removed from the tile surface within 30 minutes to one hour after grouting.
9. If grouting with MAPEI Kerapoxy^® CQ, contact MAPEI’s Technical Services Department for haze removal instructions.

1. Apply flexible caulk such as MAPEI Mapesil^® T Plus in areas of movement such as shower wall/shower floor transitions and shower curb/shower floor transitions.
2. Apply a 100% silicone-based sealant, MAPEI Mapesil^® T Plus, around the drain area.