How to Install a Ceramic Bathroom Fixture on Drywall
Imagine the horror; a visiting friend needs to use the restroom, and once he finishes his business, he realizes someone mounted the paper-holder a step or two out of reach. Now pretend your friend made a mess and needs to take a shower. After cleaning up, he opens the shower curtain and discovers he needs to walk across a slippery floor to get to the towel rack located on the other side of the room. Both of these placement issues happened because the installer failed to plan the layout with the user in mind. After living in their home for a short amount of time, more than a few people have discovered the installer either placed one of the ceramic fixtures in an inconvenient spot or neglected to install one to begin with.
Layout the Ceramic Fixture
When installing a toilet-paper holder, sit on the toilet seat and press the fixture against a nearby wall without leaving the seat. Use this as a placement guide. Hold the fixture's template against the wall in the appropriate location and use a pencil to create an outline. If the fixture manufacturer did not supply a template, sit the fixture's nipple on a piece of paper and trace its outline. Cut out the outline and use this as the template.
Use a similar method to determine a towel bar's location. Locate the bar within reach of the tub, shower or sink. Sometimes installing a set on a narrow wall requires cutting the bar with a saw and then adjusting the template's length accordingly. If the room contains an existing towel bar, measure the distance from the bottom of a post to the floor. Transfer this measurement to the new fixture's location. Hold the towel bar's template against the wall, keeping the bottom of the template even with the transferred measurement mark. Hold a bubble level on the template and adjust it until both posts sit level with each other, then trace the template's openings on the wall with a pencil.
Cut the Drywall
- Score the outline: Score the outline with a utility knife, using enough pressure to cut into the gypsum about 1/8 inch. A deep score not only cuts the drywall's paper backing, which prevents the paper from pealing but also gives the gypsum a sharp edge.
- Cut the drywall: Push the cutting tool's blade through the drywall near one corner of the top horizontal line. Cut along the top horizontal scored line, working from one corner to the other. Cut both vertical lines using the same method. Occasionally an obstruction, such as a wall stud, prevents the blade from cutting across the upper horizontal line. If so, score the top and bottom lines repeatedly with the utility knife until the blade cuts completely through.
- Clear the opening: If the opening sits inside a wall cavity, apply pressure to the top of the cutout. Pressure here makes the drywall snap along the uncut bottom scored line. The cutout then hinges back into the wall cavity; this forms a shelf for the setting material to rest on. If the cut process revealed a wall stud, carefully pry the cutout from the opening with a screwdriver. Remove any exposed drywall nails or screws.
- Verify the opening size: Hold the fixture against the opening and make sure it's nipple slides completely into the hole. The rim surrounding the nipple's perimeter should touch the wall. Remove any obstructions from the hole that prevents this.
When replacing a towel bar or other ceramic fixture that fell off the wall due to abuse or poor installation, simply remove all the old setting material and reuse the existing hole. Applying new adhesive against remnant setting material pushes the replacement fixture away from the drywall, giving a raised uneven appearance.
Ceramic Fixture Setting Material
Usually when a ceramic towel bar, or other bathroom fixture, falls off the wall months after installation, the installer used grout instead of thinset or bathroom caulk instead of construction-grade adhesive. At first blush dried grout and thinset look the same, however, over time unsanded grout fails because it lacks thinset mortar's tensile strength and bonding ability. Construction adhesive differs from bathroom caulk; construction adhesive bonds two items together while bathroom caulk repels moisture.
The appropriate type of setting material depends on the condition of the drywall and whether or not the hole in the drywall aligns with a wall stud or other structural support. Installers should choose thinset mortar when working with damaged drywall or an improperly cut hole. Unlike the mortar installation method, which locks the fixture in place as it supports damaged drywall, construction adhesives depend on the drywall's integrity for strength. Choose a construction adhesive designed for setting ceramic bathroom fixtures. I found DAP Shower Wall Adhesive works well in most situations, especially when replacing a towel bar that fell off the wall due to faulty installation.
Install With Thinset Mortar
- Mix the thinset mortar: Each ceramic bathroom fixture uses approximately one cup of powdered thinset mortar mix. Place the mortar mix in a bucket. Pour a small amount of water into the bucket and stir the mixture with a margin trowel. Continue to add small amounts of water to the mixture until the thinset takes a sturdy putty-like consistency. A scoop of thinset should hold its form without sagging. If the thinset sags, return it to the bucket and stir in enough powdered thinset to stiffen the mixture.
- Clean the drywall: Wipe a damp sponge across the work area, including the drywall's cut edge inside the hole. The sponge should moisten the gypsum just enough to change its color. This moisture helps the thinset bond to the drywall.
- Apply thinset mortar: Use the tip of the margin trowel to scoop about 1 tablespoon of thinset from the bucket. Press this mortar against the inside edge of the drywall. The thinset should lip around the opening and hug the drywall's inside surface. Repeat this all the way around the inside perimeter of the hole, using about 1/2 cup thinset. Cover the back of the ceramic fixture with the remaining portion of thinset.
- Install the ceramic fixture: Push the fixture into the hole. The thinset placed on the fixture should adhere to the thinset gripping the hole's inside edge. This combination forms the mushroom shape that locks the fixture in place. Fill the seam next to the drywall with excess thinset. Immediately clean up the mess with a damp sponge. Hold the fixture in place with masking tape until the thinset hardens, often 4 to 6 hours.
When installing a ceramic towel bar, mount one post using the above method. The notch in the post for the towel bar must face the second post's hole. Place the thinset inside the second hole and on the second post. Carefully position the bar in the first post's notch. Slip the other end of the bar into the second post's notch and install the post.
Install with Construction Adhesive
- Clean the work area: Wipe a slightly damp sponge across the drywall's surface and around the hole's perimeter, removing all dust and loose drywall debris from the hole.
- Apply adhesive to the drywall: Apply a generous amount of adhesive to any structural backing, such as a wall stud. Run a thin bead of adhesive around the outside perimeter of the hole, keeping the bead on the rim. The bead's placement on the rim effects the amount of cleanup needed. Place the bead too far onto the drywall's surface, and the excess adhesive will squeeze out onto the finished drywall's surface. Add a generous amount of adhesive around the perimeter of the hole's backside, the side facing the wall cavity.
- Apply adhesive to the fixture: Run a generous bead of adhesive around the fixture's nipple. Only cover the part that goes into the hole. The adhesive placed here ensures a good bond with the adhesive on the drywall.
- Install the fixture: Align the fixture's nipple with the hole and push the fixture into the recess until the fixture's flange touches the drywall's surface. Hold the fixture in place with masking tape; large heavy fixtures, such as soap dishes and paper holders, often require multiple pieces of tape, while towel bars often get away with a single strip. Let the adhesive dry, using the manufacturer's instructions as a guide.
- Caulk the seam: Fill the seam between the wall and the fixture with bathroom caulking. Smooth the caulking bead with a damp finger. Clean up any mess created with a damp sponge.
This article is accurate and true to the best of the author’s knowledge. Content is for informational or entertainment purposes only and does not substitute for personal counsel or professional advice in business, financial, legal, or technical matters.
© 2018 Bert Holopaw