Walk-in tile showers are the newest trend in bathroom design, a trend that has many homeowners thinking about installing tile over the drywall in their bathrooms. Is it a good idea? Can you tile over drywall in bathroom areas that aren’t your shower?
While you can tile over drywall in your bathroom, it isn’t a good idea. Drywall will eventually deteriorate from moisture, causing the tiles to crack, sag, or fall off. If you dream of a tiled shower, use an appropriate backing such as Kerdi-Board or cement board (which you can install over drywall).
Can I Tile Over Drywall?
Generally speaking, yes. Tiling over drywall is possible if the backing is properly prepared and located in an area where it isn’t exposed to moisture constantly.
If you’re wondering about tiling a bathroom, the rule above applies mostly to the shower area. As long as you have good ventilation in place (a large window and an adequate extractor fan), tiling the drywall in a bathroom gives you the same result as tiling the drywall in any other area of your home.
However, the shower area is constantly damp. Most ceramic tiles are impermeable; however, the grout isn’t. Sooner or later, water will infiltrate and get to the drywall behind.
You could now argue that there are moisture-resistant types of drywall. That’s perfectly true – and perhaps the type of drywall you have in your bathroom is already moisture-resistant. However, even the most moisture-resistant drywall won’t resist moisture exposure in the shower area.
Not only is a shower constantly damp, but the tile you plan to install won’t allow the drywall to breathe. Humidity will eventually damage the backing, resulting in the problems highlighted below.
4 Reasons Why You Can’t Tile Over Drywall In A Shower
Many manufacturers claim their drywall is perfectly safe to use in showers, but many fail to mention that you shouldn’t tile it. Here’s why.
As explained above, drywall attracts moisture, and the tile installed above it prevents the backing from drying between one shower and the other. Unlike wood, drywall won’t expand or shrink due to constant exposure to moisture, but it will crack and begin to crumble.
Without adequate backing, the tile will start to suffer, too. Depending on the type of cement or adhesive you used to fix it, this could translate into cracked tiles, sagging tiles, or tiles that simply fall off the drywall (posing a risk of injury).
Mold and mildew
Tiled or not, all drywall will develop mold and mildew in the shower. But if you can see the spots and deal with the problem promptly when the wall isn’t tiled, your fancy tiles will hide the issue.
Although you won’t be able to see the germs, they can still lead to a variety of health problems, including asthma triggering, allergies, respiratory infections, and a series of other airborne diseases.
When thinking about tiling drywall, most homeowners only think about drywall as a backing. They fail to remember that the drywall also has its own backing, generally consisting of wood studs.
As humidity damages drywall, the substrate will begin to crack. Water can travel through these cracks to the wood studs behind it, where it can lead to even bigger problems, including a mold issue generalized to the entire house.
Like any organic matter, wood will eventually rot due to constant exposure to moisture, weakening the wall structure. If you don’t deal with the matter promptly, the drywall panel could eventually fall off.
Rot aside, another thing you have to worry about is pest control. You should keep in mind that absolutely all pests love water. Thus, the moisture trapped in your drywall will act as a magnet and attract nasty termites and carpenter ants, to name just a few.
If this happens, not only will your wood studs become weak due to rotting, but the pests feeding on the wood will further weaken their structure. It goes without saying that everything will collapse sooner or later.
Moreover, termites and carpenter ants can spread to other areas of your home.
Before You Start Tiling Over Drywall
Are you still convinced that tiling over drywall is a good idea? Make sure you prepare the surface properly before tiling it. Here’s a list of things you’ll need:
- Cleaning cloth or sponge
- Paint scraper
- Paint stripper
- Protective equipment
- Vacuum cleaner
Prepare Painted Drywall For Tile
While you can tile over drywall, you should never tile over wallpaper or painted surfaces, especially if the paint has a glossy finish. That’s because wallpaper or glossy paint doesn’t provide an adequate grip.
You will have to remove all traces of paint before installing the tiles. To do this, you can either sand the wall directly (if it is painted with water-based paint) or strip the paint first (if it is painted with oil-based paint).
If you have to strip off the paint, put on the protective equipment, including a mask with a respirator, and apply the chemical stripper following the instructions on the packaging. Let it react with the paint (about 15-20 minutes in general, although it could take longer depending on the product you use).
When it stops bubbling, grab the paint scraper and remove all loosened paint from the drywall.
If the wall is painted with water-based paint, place a disc of coarse-grip sandpaper on an orbital or palm sander and start stripping down the surface. Sand until you reach the drywall under the paint, changing the sandpaper each time it gets too loaded with dust and debris.
For a better and quicker result, wipe down the dust each time you change the sandpaper.
When you’re done, remove as much dust as possible with the vacuum cleaner, then wipe the wall with a damp cloth. Let it dry before installing the tile.
Prepare Unpainted Drywall For Tile
Preparing unpainted drywall is much more straightforward. You only have to clean the surface if necessary, preferably with a degreaser. Then, sand the entire wall with medium-grit sandpaper to create a uniform surface that is not smooth.
Remove all dust and debris with a vacuum cleaner and wipe the wall with a damp cloth. Let it dry before proceeding.
Note: If either your painted or unpainted drywall is cracked or damaged, seal all cracks and openings with drywall mud and sand the surface until the patch is flush with the rest of the wall. Clean the surface and let it dry before tiling.
Installing Tile On Drywall in 7 Easy Steps
Once you’ve prepared the drywall, it is time to roll up your sleeves and get to work. Don’t worry; the project isn’t complex – simply follow the quick steps below.
1. Gather the necessary tools and materials
- Wall tile
- Tile adhesive
- Skim coat
- Grout powder or premixed grout
- Drop cloths
- V-notch trowel
- Margin trowel
- Flat-edged rubber grout float
- Bucket with water
- Tile cutter or rotary tool
- Tile spacers
- Tape measure
- Pencil and paper
- Protective equipment
2. Figure out the tile layout
Unless your bathroom has the perfect size compared to the size of your tiles, chances are you’ll have to cut some of the tiles. Moreover, you may want to install the tiles in an unusual pattern, such as herringbone, for example.
Decide how you want the wall to look once you’re done and draw a sketch. You’ll use it as inspiration during the work.
3. Treat the wall
While sanding the drywall before installing the tiles improves grip, you should still treat the surface with a skim coat.
Apply the product with a paintbrush in an even coat, and let it dry as instructed on the package.
4. Install the tiles
Prepare the tile adhesive by mixing the powder with water, respecting the proportions indicated on the package. Then, apply the mastic on the wall with a V-notch trowel (work on small sections at a time or the adhesive will dry out before installing the tile).
Start applying the tiles from one side of the wall, following the pattern you drew on paper. Press the tile firmly against the wall and place a few tile dividers on its edge. Proceed to install the next tile and repeat until you’re done.
5. Remove the extra adhesive before it dries up
When pressing the tile against the drywall, you’ll notice that some of the adhesive comes out between the tiles. However, this is where the grout should go. That’s why you must remove the adhesive before it dries out (or you risk not being able to remove it without damaging the tiles).
This is a simple operation, but it requires care and attention. First, remove as much adhesive as possible with a margin trowel.
Clean the trowel before moving to a new joint to prevent smearing adhesive all over your tiles. When you’re done, soak a sponge in water and wipe any adhesive that was left behind. You can remove the adhesive after you’ve installed each tile or wait until you’re done with an entire row, depending on how large your wall is.
6. Cut and patch the corners and edges
When tiling, it often happens to be left out with portions of the wall that you can’t cover with an entire tile. Once you’ve installed all other tiles, measure the empty spots and proceed to cut sections of tile.
Use a tile cutter or rotary tool with a ceramic tile blade. Follow the step above to install the patches. Let the tiles set for about a day.
7. Grout the tile
Grouting refers to filling the spaces between the tiles once they’ve adhered to the wall. Start by removing the tile dividers you used during installation, then mix the grout.
Standard grout is available in multiple colors; choose the most appropriate one, either in contrast or matching the hue of your tiles. Mix the powder with water following the instructions on the package and mix well (unless you’re using premixed grout).
Apply the product with a flat-edged rubber grout float; hold the tool at a 45-degree angle and spread the mixture on the tile. Spread in swiping arcs and push the compound into the joints.
Work in small areas at a time and spread the mixture until the joints are filled evenly. When you’re done, move the grout float to a 90-degree angle and drag it across the surface to remove excess grout.
Wait for a few minutes until the grout begins to harden, then wipe off the tiles with a damp cloth. You could wait until it hardened completely but will struggle to clean the tiles afterward.
Let it dry completely (about 24 hours), then apply a waterproof sealant to prevent water infiltration. That’s it.
Tiling drywall in a bathroom goes beyond skills. If you can’t stop moisture from infiltrating into the drywall, you risk damaging your entire home. Here are a few other things you should know about.
Can drywall be waterproofed?
You can waterproof drywall in your bathroom if you want to prepare it for tiling; however, you can’t waterproof it with any liquid product, paint, or otherwise.
The only right way to waterproof drywall in your bathroom is with a waterproof building membrane. Alternatively, you could replace a regular drywall panel with moisture-resistant drywall (green or blue in color).
If you decide to replace the drywall, keep in mind that green and blue drywall panels are only moisture resistant, not fully waterproof. Thus, the humidity will still damage them sooner or later.
Waterproof building membranes or panels are available at most home improvement stores, and some manufacturers provide lifetime warranties for these products.
Can I put a cement board over drywall?
You should never install cement boards over drywall in highly wet areas, including your bathroom. Instead of coating drywall with a cement board, remove the drywall panel completely and install the cement board in its place, securing it against the wall studs.
While this operation can be more expensive than waterproofing drywall, as explained above, it will provide you with solid backing for your tilework.
Tiling drywall in highly wet areas is the perfect example of bathroom or shower tiling gone wrong. Drywall isn’t an adequate backing for tile in this room because it disintegrates when exposed to constant moisture.
With this in mind, drywall should come nowhere near your shower – tile or no tile. Instead of using drywall, consider installing cement boards throughout your bathroom. You can then tile or paint them to achieve the bathroom design of your dreams.