The first two articles of this Building a Shower Series, we discussed shower framing and plumbing and the shower pan construction steps of building a walk in shower. This article discusses the final step – how to tile your shower. Prior to beginning the tiling process, the steps covered in the first two articles should be complete.
All the supply and drain plumbing should be installed, tested and ready to go. Your mixing valve(s) should be in place and calibrated as needed and plumbed with the necessary supply lines for planned shower heads stubbed out, properly supported and terminate with a securely mounted drop ear elbow or suitable fitting that is stubbed out and capped.
The Shower Tile Install: Backer Board, Thin Set and Grout
The first step of tiling a shower is to create a stable, tile-friendly surface. Tile installations require a fairly flat, stable surface that is appropriate for the adhesive thin-set mortar used to install tile.
Tile installed in wet environments (like a shower), require water-resistant backer materials. Use only tile backer products approved for shower and wet locations.
In the past, water-resistant gypsum wallboard (“green board”) was used as a low-cost wall sheathing and tile backer in wet areas like showers. This product is a wax coated gypsum wall board, that routinely failed when used in wet environments.
Building codes now prohibit the use of these products as the tile backer in showers. Do not use Green board as a tile backer in showers!
Today, there are many tile backer boards designed for bath and shower use. In general, there are four main types of backer board that can be used for shower construction. They are:
- cement board – fiberglass reinforced Portland cement (Durock, WonderBoard, Permabase)
- fiber cement board – Portland cement with added cellulose fiber (HardieBacker, BackerBoard, FiberCement)
- gypsum core board – gypsum based board with waterproof facing (Fiberock)
- polystyrene board – polystyrene board with reinforced resin facing (Kerdi-Board, ProPanel)
Comparison of Common Tile Backer Boards
|TYPE||BRANDS||COST||WEIGHT||WATER||SHOWER USE||FLOOR USE||STRENGTH||SURFACE|
|$||heavy||waterproof||yes||yes, may crack||fair, brittle||rough|
HardiBacker Use For Both Shower And Bathroom Walls
We used HardieBacker fiber cement backer board for this shower build. I chose this product over fiberglass reinforced cement board (Durock or similar) for its’ combination of water resistance and and smooth surface making it easy to paint in areas that will not be tiled. My plan was to use the HardieBacker board to sheath the entire bathroom.
As further waterproofing for the bath and shower, I added a paint-on moisture barrier. I applied this barrier over the HardiBacker in the shower and behind the sink and toilet in the bathroom.
Although wet-area approved tile backer boards are quite water resistant, many do not stop the movement of water. Vapor barrier requirements depend on local codes and specific applications (Steam Shower use, etc.).
Most installations in showers should have either a vapor barrier behind the backer board (poly sheeting) or one on top of the backer board (paint-on membranes) applied before tiling.
I prefer paint-on barriers. I like the idea of blocking water before it passes through the cement board. Also, consider that any vapor barrier behind the cement board will have fastener penetrations compared to the continuous, uninterrupted barrier that a paint-on product provides.
Two commonly available paint-on membranes are; Redgard (Custom Building Products, Home Depot), HydroBarrier, and Hydro Ban (Laticrete). I used Hydro Barrier by Laticrete (highly recommended). Both products allow thin-set tile adhesives to be applied directly to the membrane once it has dried.
Once you have installed, taped and waterproofed your tile backer, it’s’ time to install your tile.
So What Is Tile And How Is it Installed?
Tiles are thin flat pieces of clay, stone, or other material used as a construction surface finish.
Tile is often used to finish floors, walls, showers, pools, patios, and counter-tops. Tile finishes are very durable and perform well in wet environments.
Tiles are installed side-by-side using mortar based adhesives called thin set. The gaps between the tiles are then filled with grout; a durable filler often mortar-based with or without sand.
The Layers Of A Tile Surface
- Layer 1: Stable, smooth, tile backer surface (concrete, tile backer board, etc)
- Layer 2: Tile adhesive (thin-set mortar, mastic)
- Layer 3: Tile
- Layer 4: Grout
- Layer 5: Tile and Grout Sealant (optional)
How To Pick The Right Tiles For Your Shower
Tiles used in shower construction should generally be durable and have low water absorption characteristics.
Tiles are classified by the ISO (International Organization for Standardization) for 16 different standardized characteristics including water porosity or absorption.
Tiles with the lowest rates of water absorption (<0.5%) are classified as “impervious” and generally made of Porcelains. Porcelain are formed by heating ceramics to high temperatures to give glass-like characteristics (vitrification). Ceramic tiles can be heated to a range of vitrification points and are classified as:
- Non-vitreous – water absorption of > 6.0% (ceramic)
- Semi-vitreous – water absorption of > 3.0% but < 6.0% (ceramic)
- Fully Vitrified – water absorption of > 0.5% but < 3.0% (ceramic)
- Impervious – water absorption of < 0.5% (porcelain)
Impervious or Fully Vitrified tiles are often the best tiles for shower walls and floors, but many common ceramic tiles used in shower are rated non-vitreous. Non-vitrified ceramics or natural stone tiles can be used in showers, they just tend to be more difficult to keep clean and may be susceptible to mineral and other staining. If using these products it is important to seal, frequently clean and reseal these materials.
Understand that many tiles sold as shower tiles will absorb and pass water. Even the most impervious tile installations will have grout seams and grout seams are generally very water porous and tend to crack over time. It’s OK if water moves through tiles and grout lines IF the underlying shower wall and pan construction are sound and water impenetrable. Obviously, lower porosity tiles and grout finishes reduce the water moving into the shower wall and can be important.
We have a walk-in shower we tiled with Carrara marble tile. We carefully sealed the tiles after installation, but they do hold water after use. Because we used a paint-on waterproofing membrane over our tile backer board that lives under the tile, it’s probably fine long term. Will these tiles tend to stain and be more difficult to clean? Sure. The point is, if the underlying shower structure is well built with approved backer board and a water-proof surface membrane, more permeable tile is likely fine.
The same argument can be made for the shower floor tile. The tile surface of your shower pan (floor) is not totally waterproof. Water will move through the grout lines, the tile (depending on the tile) and any imperfections that develop over time. It is the job of the shower pan, with its’ embedded waterproof liner, that is responsible for a leak-free shower floor.
So, bottom line, using less than impervious tile on shower walls and the floor will work if the underlying structure is properly built, but will require more work and maintenance.
Our main home is an example of this. We re-built our bathroom shower 4 years ago and used large Carrara marble tiles for the walls and a marble mosaic for the shower floor. Both are very porous and readily hold and pass water, but were installed over cement backer board that was completely sealed with a paint-on membrane and a mortar shower pan with an embedded shower liner.
Four years later, our marble-tiled shower still looks great. It takes a bit of work to maintain (we squeegee daily after each shower!), but it can work if done properly.
Shower Tile Size and Surface Characteristics
Tile size and surface finish of shower tile should be considerations as well.
Tile surfaces characteristics should match the function and location of the shower tile. Wall tiles with glossy, smooth and durable finishes are easy to clean and easily stand up to cleaning and scrubbing. Shower floor tiles with glossy, slippery surface finishes can be dangerous. Consider choosing a textured, less-slippery finish tile for the shower floor.
When choosing tile size for your shower, consider the desired finished look, grout lines and the flatness of the surfaces in your shower. Using larger tiles tends to give a more modern, sleek look and result in fewer grout seams to clean later. Smaller uniform tiles finish with many grout lines, but look classic and install better on slightly curved or irregular surfaces.
Shower floors (shower pans) are intentionally sloped and generally require smaller, mosaic-style tiles to accommodate the sloping curves of the shower pan.
Tile Layout Patterns and Tile Grout Lines
When planning your shower tile layout, consider the tile layout pattern design you would like. There are many different tile layout patterns which give different looks. Stacked, straight, brick patterns, classic subway (what we used), herringbone, french, vertical, and many others. Pick a pattern that matches the tile and the projects. For our cabin shower, a classic 50% brick (subway) layout with classic 3″ by 6″ subway tiles was perfect.
What is Thin-set Mortar and Which Thin-set Mortar Should I Use For Shower Tile
Thin-set mortar or thinset, is a Portland cement based mortar mix of fine sand, Portland cement, water and often additives to retain moisture during curing and to improve performance of the mortar.
The main two categories of thin-set mortar are generally those fortified with polymers (like latex) often called “Modified or Fortified” and those that are not fortified known as “Unmodified”, “Dry-set” or “Unfortified” mortar.
Polymer fortified thin-set mortars add latex or similar polymer compounds to improve tile adhesion and bond-strength (depending on the surfaces), water resistance, tolerance to freeze-thaw cycles, prolonged application and working times and improved flexibility and durability.
Historically, un-modified mortar was used when tiling over concrete, cement board and dry-wall and modified mortar was used to install tile over challenging surfaces or those requiring improved initial bond (like wood, old tiles, ceilings, etc). Today, many tile manufacturers specify the type of thin-set mortar to use for a specific tile. It is important to use the proper thin-set mortar for the type of tile and conditions of the specific install, so carefully check the recommendations for the tile you plan to use and the recommendations of the specific mortar.
That said, I almost always use a modified thin-set mortar for my tile installs. Modified mortars are a bit more expensive, but for the smaller projects I tend to use if for, the extra cost is more than worth it.
Which Notched Trowel Size Is Correct for The Tile I Plan To Use
The proper notched trowel size is determined by the size of the tile you plan to install and the type of surface it will be installed on.
The goal is to provide just the right amount of thin-set mortar to properly set the tiles – enough to cover most or all of the backside surface of the tile, but not too much that the mortar bleeds out through the tile grout seams leaving insufficient space to apply grout.
The ANSI (American National Standards Institute) guidelines for tile mortar require 80% mortar coverage for all installations except for wet or exterior installations which require 95% coverage. Read the guidelines for tile mortar coverage and notched tile size here.
The following table will, in general, provide sufficient thin-set mortar coverage when installing standard tile to a relatively smooth surface (like backer board):
1/4″ x 1/4″ V-Notched
|2″ – 4″ wall tile||3/16″ x 1/4″ V-Notched|
|4″ – 6″ tile||1/4″ x 1/4″ U or Square Notched|
|6″ – 8″ tile||1/4″ x 3/8″ U or Square Notched|
|8″ – 12″ tile||1/4″ x 3/8″ U or Square Notched|
|12″ – 24″ tile||1/2″ x 1/2″ U or Square Notched|
If you are unsure if the trowel you are using is the correct size, try installing a few tiles. The tiles should settle into the thin-set with good adhesion. If thin-set is oozing out of the grout spaces above the level of the tile surface, then there is too much thin-set and the notched trowel size is too large. If you remove the trial tiles, you should see near complete coverage of the back of the tile surface, if there is insufficient mortar on the back of the tiles, the notched trowel size you are using is too small.
OVERVIEW | Tile a Shower
SUPPLIES LIST | Tile a Shower
- Ceramic Subway Tile 3" x 6" Daltile Restore Bright White 3 in. x 6 in. Ceramic Subway
- White 1" Hex Marble Mosaic Tile Jeffrey Court Statuario Hex White 12 in. x 12 in. x 8 mm Marble Mosaic Wall Tile
- Cement Board Tape FibaTape FDW8436-U 2-Inch by 150-Feet Cement Board Tape-Alkali-Resistant/Self-Adhesive
- Floor Mix Mortar Quikrete Sand/Topping Mix For bench build
TOOLS LIST | Tile a Shower
STEPS | Tile a Shower
- Install the tile backer board
Find and wear proper safety equipment when handling silica-based products like cement board. Always wear a mask and googles when cutting, handling and installing cement board products. A word of warning before you start:When working with and especially cutting any cement board product, use great care to avoid silica dust formation and exposure. Exposure to silica dust is linked to lung cancer and the lung disease silicosis. Always wear an approved dust mask (N-95) when working in the presence of silica dust. Use manufacturer approved cutting methods (shears, score and snap) and clean up (HEPA filter vacuums or wet clean up, avoid sweeping or methods that create dust).
So, to begin, plan placement and installation of a shower-approved tile backer product. The tile backer will generally be installed only in the immediate shower area and any surrounding areas where tile will be installed.
We actually over-engineered our bathroom and sheathed all the walls and ceilings with HardieBacker 500 1/2″ cement board. The thought was this, since the walls are open, why not use the most moisture-proof sheathing we can? So we did. But back to the shower build…
Prior to installing the shower backer board, if you plan to use a poly sheeting moisture barrier, install this first. If using a paint-on water-proofing membrane you do not need to install poly sheeting (it actually may be a bad idea to use both as moisture can be trapped between the moisture barriers.
When installing backer panels, you typically can orient the panels horizontally or vertically – check the installation instructions for your product. Vertical edges should be supported and land on framing members. Install backer board by screwing panels to wall studs using cement board screws spaced every 8″.
Avoid placing fasteners within 2″ of edges and at least 3/4″ from the panel edges if possible to help avoid cracking the panel. Ensure that fastener heads are flush to the panel surface.
Roofing nails may be used instead of screws and in some cases are easier to use. Screws may be preferred for ceiling panels and fastener length should allow for at least 3/4″ fastener penetration into framing members for ceiling mounting. Space panels according to manufacturers recommendations – generally 1/8″ – 1/4″ to allow for wall movement and thermal expansion.
When mounting the backer board, horizontal blocking is not necessary for most boards but does add stability (we added horizontal blocking, where it was simple to do).
Cut panels using manufacture-approved methods like scoring and snapping the panels. Always wear a particle mask or respirator when working with these products. Avoid using of high-speed power tools (grinders, circular saws) unless they are have attached dust evacuation systems. Specialized carbide tip scoring tools are available and work well.
- Apply Cement Board Tape and Thin-set to Panel Seams
Once the backer board is installed, use the thin-set you plan to set your tiles in (likely a latex modified thin-set) to fill the gaps between the backer board panels.
Over this thin-set, apply cement board approved (alkali-resistant) fiberglass mesh tape. Smooth seams and tape with additional thin-set. See #6 below for more information on mixing thin-set mortar.
- Apply Elastomeric Paint-On Waterproofing Membrane To Walls and Ceiling
Waterproof your shower by applying a paint-on elastomeric surface water barrier. Shower approved tile backer boards are tolerant of water, but they do not stop it. Protect your framing and wall cavities by applying a vapor barrier.
Although it is acceptable to use plastic sheeting installed behind tile backer board as a vapor barrier, it is not the best practice.
Using paint-on waterproofing barriers block water at the surface of the backer board. Why not deny water passage into your wall, instead of trapping it behind the backer board with plastic sheeting?
There is a variety of paint-on waterproofing products available. I used HydroBan from Laticrete. This paint-on product is easy to apply and does not require fabric reinforcement at the corners and seams (some products do).
Although no fabric reinforcement is necessary, corners, penetrations, floor-wall transitions and other critical areas should be pre-treated with a liberal application of the product prior to applying two field coats.
Allow the product to cure before setting tile (2 hours for Hydro Ban). Most paint-on membranes allow the use of thin-set adhesives directly over the paint-on membrane once cured.
- Plan and Mark Out Tile Layout
Plan the layout of your shower tile. Start by creating a level baseline just above the shower pan. Mark this baseline directly on the shower wall with a pencil or marker. Also mark significant structures (the window in our case) with a horizontal reference around the shower to help plan tile seems.
Plan out tile install. Start with level reference. Mark the walls with horizontal and vertical reference lines prior to setting tile. Notice plaster guards over mixing valves prior to starting tiling.
Dry install tiles or use a “story pole” (a stick with markings that reference stacked tile seams to help plan tile install) to adjust your base starting height to facilitate tile seams falling on desired targets (the window ledge, for example). You can also build a wall model away from the shower on a sheet of plywood, paneling or cardboard to layout tile to plan for seams and plan cuts. Adjust the starting baseline as needed to avoid unnecessary or very thin tile cuts.
Once desired baseline starting point is established, create a level base for the initial row of tile using a straight edge, level or similar. This base should start a tile width or more above the shower pan. For our base straight edge, we used several inexpensive plastic levels supported by blocks.
From this horizontal reference, draw a single or multiple vertical plumb reference lines on the to be tiled wall to help maintain a uniform, straight and level tile install. Prior to installing tile, ensure that mixing valve components are protected with included plaster guards or tape.
- Prepare Materials, Thin-set Mortar for Tile Install
Prepare to install tile by collecting all necessary supplies, tile and tools. Once thin-set is mixed and applied, you will have a fairly short period of time to set the tiles. You should have everything ready to set tiles once the thin-set is applied.
For our shower tiles, we used off the shelf 3″ x 6″ white ceramic subway tiles from The Home Depot. These tiles did not require the use of tile spacers as they have self-spacing nubs on their sides, which helps speed installation by avoiding the need to place tile spacers during the install. Installing the tiles using these self-spacers provides a grout seam of ~ 1/16″. You could always use these same tiles with larger spacers to create wider grout lines if you like.
If using tiles that are not self-spacing, use tile spacers to create uniform grout gaps between installed tiles. If you use tile spacers, decide on the proper spacer size and have them ready for use. In general, smaller tiles typically have smaller spacing (1/16″ – 1/4″) while larger tiles will be set with wider spacing (1/4″ – 1/2″)
Most very small or mosaic tiles will be mounted on a mesh backing with fixed spacing between individual tiles. You will still need to control the spacing between these pre-mounted mesh sheets.
Once you have a plan for tile spacing, assemble enough tile (and tile spacers if using) to complete your initial thin-set application. Thin-set adhesives generally have short working times and should be mixed in small batches that can be completely used within the products working time. In general, this will be area equivalent of one 3′ x 5′ backer board sheet for small tiles and several sheets for larger tiles.
For the 3″ x 6″ subway tiles we used, we found that we could easily cover the area of one 3′ x 5′ backer board panel with each thin-set batch
- Mix thin-set mortar and Start Tile Application
Using a five gallon bucket or similar, mix a small batch of thin-set according to the instructions given by the product you are using. We used latex fortified thin-set (Pro-Lastic from Superior Adhesives and Chemicals) from the Tile Shop.
For most products, start with just the liquid (water or latex if two-part) in the bucket. Slowly add the dry mortar while mixing. Continue to add the dry component until the thin-set has the consistence of peanut butter. Proper thin-set should stick to the bottom of a trowel when turned upside down. Mixing attachments for drills make the task of repeatedly mixing mortars and grout much easier. We used a mixing paddle connected to a 1/2″ heavy duty drill and I highly recommend doing the same.
Then, using the proper sized notched trowel, apply an even coat of thin-set to a small area just above the beginning point of your tile install. The proper notched trowel size is determined by the size of the tile you plan to install and the type of surface it will be installed on. The goal is to provide sufficient mortar coverage of the back of the tile surface for proper adhesion of the tiles to the backer board.
If you are unsure if the trowel you are using is the correct size, try installing a few tiles.
The tiles should settle into the thin-set with good adhesion. If thin-set is oozing out of the grout spaces above the level of the tile surface, then there is too much thin-set and the notched trowel size is too large. If there is insufficient mortar on the back of the tiles (they should be completely covered with mortar), the notched trowel size you are using is too small.
Begin thin-set application above the starting point for your first row of tiles. Apply thin-set to an area that you believe you can finish tiling within the working time for the thin-set mortar product you are using (generally 10 – 20 minutes). Apply an uniform layer of thin-set using a notched trowel.
Start installing tiles beginning at the bottom row at a corner using the level straight edge base that you previously assembled. Set each tile into the thin-set mortar bed by applying gentle pressure and moving the tile back and forth slightly. As you install tile, reference the previously marked plumb vertical lines to ensure proper tile alignment.
When staggering rows to install the subway tile in a “brick” pattern, a good trick to help center tiles is to use a tile turned sideways as a guide. Subway tiles are half as wide and they are long creating the perfect spacer.
- Continue tile installation, Complete rows with Cut Tiles
For almost any tile job you will need to cut tiles.
There are several ways to cut tile depending on the type of tile you are using. The best way is typically a wet tile saw. Many tiles can also be cut using a score and snap tool. Small cuts can be made with a hand nippers.
Wet tile saws use hardened circular blades cooled by water to cut tile. Wet saws provide very clean cuts and typically employ a sliding guide that easily produces straight cuts. Wet saws can be expensive, but many home improvement stores rent tile saws and having a wet saw for a major tile project is often worth the money.
If you are using a thin ceramic (like the subway tile we used) or other easy to cut tiles, a simple score and snap cutter and hand nippers may be sufficient for your project.
When cutting partial tile to end rows at the corner, cut the tile to fit with a small (1/8″ or so) gap. Cutting end pieces to close can cause tiles to buckle with wall movement and these small gaps will be covered by the adjacent wall tile.
In addition to cutting tiles you will probably need a supply of various trim tiles depending on your project. Trim tiles offer easy transitions (coves, etc) and finished edges at corners and the end of rows (bull nose finish tiles). We used two types of bull nose finish tiles to complete the window edge, the shampoo niche and the leading edge of the shower.
- Install a Corner Shower Bench (optional)
A shower bench can be built into the shower framing or added during the tiling process. We did not frame in a bench, but planned to add a bench during the tiling process. We built our shower bench using the Better-Bench® system by Innovis Corp. The system features an aluminum pan which is mounted onto the shower wall and then filled with floor mud and tiled to create a very strong, concrete shower bench. The system offers several sizes of triangular and rectangular forms.
Building a shower bench with the system is easy. First, install the aluminum frame onto the shower wall. Fill the frame with floor mix mortar (sand and Portland cement), trowel smooth with slight slope to shower and finish with tile. The finished bench is very strong (rated for 400 lbs.) and has the benefit of open space below the bench, unlike many framed in benches. The Better-Bench® at Amazon..
- Complete Setting wall and ceiling tiles, Adding Edge trim and details.
Continue setting tile working your way up and around the shower. Carry plumb and level lines onto side walls prior to setting tile. If you need to stop tiling during the process but have areas of thin-set already applied to the wall, simply scrape off the thin-set before it dries.
Use trim tiles to finish edges and complete exposed tile edges. For this project we used short side bull nose tiles to finish the vertical leading edges of shower entrance (see below image) and for the window and alcove, and long side bull nose tiles to provide a finished edge for horizontal borders of the window opening and alcove.
To personalize the shower, we added a few small tiles that we brought home from a trip to Italy. As long as the tile thickness is similar, it is quite easy to add a contrast or a detail tile within the tile field — just cut out the space for the tile leaving a grout gap to match the main tiles.
Tile the shower curb we used the same white subway tiles we used for the shower walls. For the top or threshold of the shower curb, we used a 6 1/2″ x 3/4″ x 36″ pre-cut Carrara marble threshold from the Tile Shop. Thresholds made from many different materials are readily available from home improvement and tile stores. Our shower threshold was longer than 36″ so we needed to use two pieces seamed to fit our shower.
- Grout the tile
After all the tiles are installed and the thin-set is cured (24-48 hours), grout the tiles.Grout is available in sanded and non-sanded forms. Sanded grout is generally used for grout seams greater than 1/8″. Non-sanded grout is used for grout seams 1/8″ or narrower and for use with tile surfaces that could be scratched by sand.When choosing a grout for wet areas use latex fortified mixtures. We used Polyblend polymer-modified non-sanded grout available at The Home Depot stores.
Grout, like thin-set mortar, also has a short working time and should be mixed in small batches. Mix an amount of grout that you can apply in less than 30 minutes. Consult the specific instructions for the product you are using, and know that some modified grout products require an admix in addition to water.
Prior mixing and applying grout, look over the entire tile install for excess thin-set in the tile joints. If tiles joints are full of thin-set, there will be little room for grout. Remove excess grout between tiles using a small nail or a standard screw driver turned sideways.
Mix grout to a smooth, lump free consistency similar to peanut butter. Occasionally mix grout as you are using it and discard once it stiffens or becomes lumpy.
Apply grout to tile using a grout float held at a 30 to 45 degree angle to the tile surface. Work the grout into the tile joints using a criss-crossing motion. Once the grout joints are uniformly filled, tip the grout float to a steeper angle (70 to 90 degrees) to remove excess grout from the tile surfaces.
Next, remove excess grout and smooth the grout seams using a slightly damp sponge rinsed frequently in a 5 gallon bucket of clean, cool water. Use as little water as possible, but thoroughly rinse sponge repeatedly during the process. Excess water can weaken grout.
After sponge cleaning, allow the grout dry until a haze appears on the tile surfaces (30 minutes to several hours). Remove this haze by wiping with a dry cotton cloth. Grout haze removal products are available for difficult to remove grout haze, but these products should generally not be used until the grout has cured (24 – 48 hours).
Some tiles with porous surfaces are prone to collecting grout haze and may benefit from pre-sealing the tile surface with a light coating of tile sealer prior to grouting. If you do this, use care to apply sealer only to the face of the tile and avoid contact with the grout joints as this may compromise the bonding of the grout between tiles.
- Tile the shower Floor
In theory we would tile the shower floor (shower pan) first to promote our desired water path down the wall tile and over the shower pan. But for most shower builds, this layering is not necessary as the shower liner protects this area of the shower.
Even if water did get past the tile at this interface, the shower liner will redirect it to the drain. Remember the shower liner runs up the base of the shower walls some distance (usually at least as high as the shower curb) to waterproofing the coves and base of our shower pan. So, for practical reasons, many installers complete the shower pan tiles last, to help prevent damage to them while installing tile on the shower walls and ceiling.
To begin tiling your shower pan, dry set you tile in the pan prior to applying thin-set. Tiles should follow the slope of the pan and still have solid support. If tile are unsupported or rock back and forth you may need to cut tiles to follow the slope or use smaller tiles.
Some correction for unsupported tiles can be made up with the thin-set mortar bed, but tiles should be relatively stable prior to setting them. Smaller tiles, especially small mosaics (pre-mounted on mesh) tend to work best on the sloped shower pan surface.
Prior to setting the shower pan tiles, check the drain height in relation to the finished tile height (add a bit of height for the not yet applied thin-set) on the shower pan. The drain should be level or slightly lower than the finished surface of the shower pan tile.
If drain height correction is needed, most drains allow adjustment by turning the drain riser, which in many designs, is threaded, and moves up or down with turning.
Once satisfied with the tile layout and drain height, remove tiles, clean the shower pan (make sure the surface is smooth and free of any thin-set, grout or debris), and prepare to set the shower pan tiles.
Mix enough thin-set mortar (latex modified thin-set for wet areas) to cover the shower pan. Apply thin-set and set tiles. Ensure good contact between the tiles and thinset — your goal should be that every tile is soundly set into the thin-set with no gaps or unsupported tiles. This is important as these will be weight bearing tiles.
When setting the tiles, make sure the top surface of the tiles is smooth and each tile flat relative to each other. You do not want high spots or sharp edges in the finish of your shower floor. Prevent high edges and tiles by smoothing the surface of the tiles before the thin-set hardens. A good trick is to use a short piece of 2 x 4 covered with fabric or carpet to help level the tiles as you set them. Push the covered 2 x 4 into the tiles as you slide it over the entire surface of the floor tiles. Use your hand to feel for high spots or sharp edges and correct before the thin-set hardens.
Allow the thin-set to cure for 24 – 48 hours, then grout the floor pan.
- Seal The Tile and Grout lines
Allow grout to cure for at least 48 hours before applying sealer. Make sure tile surfaces are clean and free of thin-set, grout or grout haze. If necessary clean tile surface with grout haze remover prior to sealing. Follow the directions of the product you plan to use (we used 511 Impregnator Sealer from Miracle Sealants). For most products, apply the sealant to the grout seams using a foam brush, or sponage to saturating each joint. Then use a sponge to lightly coat the surfaces of the tile.Allow sealant to soak in for several minutes. Then, using a clean, dry soft cloth, wipe off the excess sealant from the tile surfaces before it dries. Repeat. Test sealant by dropping water onto the grout and tile surface. If properly sealed, the water should bead and run off the surfaces. If the water does not bead, repeat sealant application until it does.
- Mount Shower Plumbing Fixtures and Trim
Install the shower head arm (supply pipe), shower head(s) and knobs and trim of your controls. The shower arm is typically a short, slightly bent 1/2″ pipe that is threaded on both ends and finished to match your shower fixtures. The shower arm connects the rough in plumbing behind the wall with the shower head. The rough in plumbing that the arm connects to usually ends with a drop ear elbow fitting designed for this purpose. Often, this drop ear elbow is connected to a short piece of 1/2″ capped pipe (“stubbed out”) when the rough in plumbing is installed. If yours is stubbed out you will have to remove the pipe stub before installing the shower arm. Before you do make sure the mixing valve is off.
To install the shower arm, first wrap several rotations of teflon tread tape or apply teflon thread dope to the wall end of the shower arm. Wrap the Teflon tape clockwise as you hold the threaded end facing yourself. Proper wrap direction of the thread tape helps maintain the tapes integrity when installing the pipe.
With the thread tape applied, pass the shower arm through the wall and into the drop ear elbow of the rough plumbing. Be careful to line up the threads properly to avoid cross-threading the elbow (which is copper or brass and quite soft). Hand tighten to the point of proper alignment.
Then wrap a rag or strip of rubber around the pipe to protect it, and using an adjustable wrench or pipe wrench tighten the shower arm 1 – 2 additional turns until the shower arm is properly align. Do Not Over Tighten!! Remember that the drop ear elbow is soft and very hard to replace!
Next, test the shower arm for leaks by capping the shower end of the elbow and turning on the water. Use a flash light to peak into the wall at the drop ear elbow by looking through the space between the shower arm and the hole cut in the wall (the hole should be slightly larger than the pipe). If no leaks, turn the water off, and remove the cap placed to test the shower arm. Next, slide the shower arm escutcheon (round trim piece that covers the hole in the wall) onto the shower arm and slide it down to the wall.
To install the shower head, first wrap several wraps of Teflon pipe thread tape around the threads of the shower arm pipe. Wrap the tape in the same direction you will be turning the shower head to tighten it (clockwise) to avoid unwrapping the tape as you turn the shower head.
Tighten until hand tight, then tighten an addition 1 – 2 turns with a wrench. Protect the finish of the shower arm and shower head with a folded rag if needed. Check for leaks. If leak, re-tighten.
Finally, install the mixing valve trim plate and knobs. Follow the directions of the manufacturer of the product you are using. Trim plates should install flush to the wall. Once installed, carefully run a bead of silicone or elastomeric sealant (lexel) around the trim plate.
Tape the trim plate and shower wall with painters tape for a neater caulk application. Leave just enough of a gap between the tape for the caulk bead. Smooth caulk with tape still on, then remove tape. If using an elastomeric sealant (like Lexel), work very quickly to smooth the caulk bead as the surface of these sealants firms very quickly. Before using the shower, let the tile sealant and caulk cure for 24 – 48 hours. Remember to refresh the grout sealant and check the condition of the caulked areas periodically.