Wall Mounted Toilet Install
How to Install a Wall Mount Toilet
When planning our cabin bathroom remodel, we were looking for ways to open the space and improve the usability of the small 8′ x 5′ bathroom and decided to install a wall mounted toilet.
We knew if we moved the toilet off the floor and exchanged it for a wall mounted toilet, we would open the room and save a bunch of floor space.
Unfortunately, I had never installed a wall-mounted toilet or knew anyone that had. I know they are popular in Europe, and I love the concept, but not knowing much about them, I was hesitant to proceed.
We did proceed and, as it turns out, it was one of the best remodeling decisions we made for the cabin. Wall-mounted, floating toilets are nothing short of amazing! I cannot say enough about the Geberit / Toto wall mounted toilet system we installed. They are really that good.
So, if you are thinking about a wall-hung toilet system, congratulations. It’s a great idea — just do it.
This article will walk you through our project of installing a residential Geberit in-wall toilet tank and frame system with a TOTO wall-mounted toilet bowl.
To install a wall-mounted toilet from scratch you will need four main components:
- Wall mounted carrier/ concealed wash down tank for wall hung toilets (Geberit© 111.728.00.1)
- Flush actuator kit and wall plate to fit the carrier (Geberit© 115.777)
- Wall hung toilet bowl that fits the frame / tank unit you are using (Toto© Aquia CT418FG)
- Toilet seat to fit the toilet bowl you are using (Toto© elongated soft close SS164)
For the in-wall toilet rough-in you will also need:
- A well framed 2×4 or 2×6 wall capable of supporting 800 lbs (we beefed ours up for this)
- Water supply run in wall to top of unit (1/2″ min)
- Waste plumbing (3″) from below to base of the unit
- Wall finished with tile, tile backer board, cement board or gypsum board
In addition to the above, you will need access to the waste and supply plumbing and will need to open the wall cavity in the area you plan to install the unit. For us, access for the install was no problem — we had the floor and walls open to the frame for our bathroom remodel.
Wall Hung Toilets: Awesome, But Expensive
Installing a wall mount toilet with a concealed tank requires a fair amount of work, and it is also expensive. Expect to spend close to $1,000 for the components alone. If you are not planning on doing the plumbing and installation yourself, expect to at least double that with the install and plumbing costs.
That said, and after using our wall hung toilet for several years, I am fairly sure I will never install a standard floor mounted toilet again!
Not only is it the best toilet we have ever had (It has never clogged in two years of use — in fact, we have never had to use a plunger on it!), it saves a ton of floor space. It also allows for easier cleaning of the bowl and the floor under it. Awesome!
So, if you are still with me and as excited as I am about a floating toilet on the wall, read on for a step by step, how-to install a wall hung toilet. Happy flushing!
Wall Mounted Toilet Install – Frame, Tank and Toilet
- Level: Intermediate
- Time: Days
- Complete toilet cost: $600 – $1000 +
Wall Mounted Toilet Install – Project Big Picture
- Open the wall to the framing
- Ready the supply and waste plumbing
- Install the in-wall frame and tank system
- Connect the supply and waste plumbing
- Finish the wall
- Mount the toilet, install the seat
- Install the flush actuator and cover
Components and Materials – Wall Mount Toilet Installation
|Item||What I used|
|In wall toilet tank and frame system|
|In wall toilet dual-flush actuator cover kit|
|Toto Wall mounted toilet bowl|
|Toto Toilet seat|
Tools and Supplies – Wall Mount Toilet Installation
- Tools and supplies for opening wall and framing
- Tools and supplies for supply and waste plumbing
- Tools and supplies for mounting the unit
- wrench or socket set
- adjustable wrench
- Caulk (silicone or elastomeric sealant), painters tape
Install a Wall Mounted Toilet System – Step by Step
- Open the bathroom wall where the toilet is to be mounted.
Plan the location you would like to install the unit. When planning the location, consider the path of the eventual supply and waste plumbing. Then, demo the wall structure in this area to expose the wall framing and plumbing.
For your future plumbing, you will need a 1/2″ cold water supply line to the unit and a 3″ waste line below the unit.
- Modify the wall framing for the in-wall toilet carrier frame and tank unit.
There are several types of in-wall toilet tank/frame units available to fit most traditional wall framing. Our cabin bathroom has standard 2 x 4 wood stud construction.
The Geberit unit designed for 2″x4″ 3 1/2″ deep wood framed wall construction is the Geberit 111.728.00.1. This unit fits standard 2″x4″ framed walls depth, but to make up room for the water tank in this shallow wall, the unit is wider (23 1/2″) than traditional 2 x 4 stud spacing (15 1/2″) and typically requires moving studs to accommodate the width.
For us, this was not a big deal as we were in the middle of a total bathroom renovation and could easily revise the framing for the 23 1/2″ wide unit. In addition it’s the width, the unit calls for wall framing load bearing of 880 lbs.
Knowing this, I doubled the studs framing the cavity where the in-wall toilet frame would be mounted and reinforced the studs with Simpson Strong Tie gusset plates and structural grade fasteners
- Plan and run supply and waste plumbing.
The toilet system will require a water supply line and a waste pipe within the footprint of the wall cavity. With the walls and floors of the bathroom open for our renovation, it was easy for us to add the exact plumbing we needed for the unit.
For the toilet waste line, we ran a long sweep (indicated for all drains, especially toilets) 4″ to 3″ Sanitary Tee just under the unit. This Tee was then stubbed out with a short section of 3″ PVC that passed through the floor plate of the wall framing directly under the unit.
To pass through the floor plate of the wall framing, we didn’t cut through the floor plate, but just removed a short section of it (3″ PVC pipe has the same width (3 1/2″) as the floor plate 2 x 4). To support the cut ends of the floor plate, I added additional blocking between the floor joists. This extra support under this portion of the wall framing will help the floor support the weight of the unit in use.
This centered waste pipe location is required for the Geberit unit designed for 3 1/2″ wall depth (2″ x 4″ stud wall). Geberit also has units designed for deeper walls (2″ x 6″ framing) that allow for a side as well as a vertical waste pipe path.
For the water supply, I ran 1/2″ copper from the crawl space. I pass this line through the floor plate, along the left rear of the wall cavity to accommodate the front-mounted toilet carrier frame.
- Install the toilet carrier concealed tank unit in the wall cavity.
Mount the wall frame and concealed toilet tank unit in the wall cavity. I used the Geberit 111.728.00.1 unit designed for 2 x 4 framed walls. As explained above, the unit is 23 1/2″ wide.
To start, I revised the stud cavity width where I planned to mount the unit to accommodate the 23 1/2″ width. When framing this cavity, I used double studs reinforced with Simpson Strong-Tie gusset plates to help meet the load bearing requirements of the unit.
Prior mounting the unit, adjust the frame for your desired future toilet bowl and seat height. The Geberit unit allows for seat height adjustments of 15″ – 19″. ADA toilet seat compliance is between 17″ – 19″ (often called comfort seat height). We set our toilet seat height at 17″.
With this adjustment made, temporarily install the frame into the wall cavity. The frame should fit snugly in the wall cavity with the sides of the frame touching the bordering studs. Use a level to ensure the unit is level and plumb within the wall cavity.
Then, check to make sure the carrier frame is flush with the front face of the studs. Then, mark the top height of the frame on the bordering studs to indicate the location of to-be-added horizontal framing.
Next, install a piece of horizontal 2 x 4 blocking within the wall framing just above the top of the unit. Although not required, this horizontal blocking is a good idea, as it will strengthen the framing around the unit.
With the horizontal blocking installed, mark the frame mounting hole locations on the top and bordering studs. Mark the bolt hole locations at the base of the unit as well.
Remove the unit and drill holes in the framing at the marked mounting locations. Use the proper size drill for the fasteners you are using (check the installation documents). Typically, wood framing will require lag bolts at the base and standard bolts with nuts at the sides (and top if using).
For my install, I used lag bolts on the sides (I had double studs to bite into) and base of the frame and standard bolts with nuts at the top of the frame. If using lag bolts be sure to drill the proper size hole into the wood framing prior to installing the bolts. If the holes are too small, you can crack the framing. If the holes are too big, the bolts may lack holding power.
If you have access to both sides of the studs, using bolts may provide a stronger mount.
- Install rough in discharge plumbing.
Once the frame is secure within the wall cavity, install and connect the outlet (waste) pipe fittings and connections.
Begin by connecting the supplied 90-degree outlet pipe fitting (black in color) to the carrier frame using the supplied, two-piece clamp bracket. Then connect the discharge of this fitting to the stubbed out 3″ PVC waste line using the supplied hubless connector. You may have to trim the 3″ PVC waste line prior to connecting.
Once the connection is complete, protect the plumbing connection opening by capping them with the supplied yellow plaster caps. These covers will keep debris out and protect the ends of these connections. Use painters tape if the pre-made covers are not available.
Next, connect the toilet bowl mounting threaded rods to the carrier frame. You will not need to set a particular depth for these mounting rods yet, just screw them into the frame far enough, so they are not in the way during the remaining construction. Once installed, pass the clear plastic tubing thread protectors over the installed threaded rods.
- Install and connect the supply plumbing.
Run cold water supply plumbing to the top of the concealed wall carrier unit and connect to the supplied valve.
Plan the valve location to allow for the passage of the valve into the carrier unit through capped access hole at the top left of the unit.
Use drop ear elbow fitting at the end of the supply line to allow for a secure connection for the supply plumbing (see photo to the right).
Connect the Geberit supplied supply water valve to the drop ear elbow (after applying several wraps of Teflon tape in a clockwise direction when looking at the distal end of the fitting). Then pass the valve into the carrier through the access hole (remove the cap first) at the top left of the unit.
Next, secure the drop ear elbow to the wall framing using a block of wood located above the elbow (see above rear view of the unit in step 5). Before mounting the elbow, make sure the passed supply valve outlet is oriented to the right front of the unit to allow for easy connection to the water line inside the unit.
With the supply line securely mounted and the supply valve passed into the carrier and properly align, connect the supply valve to the water tank within the unit using the supplied braided stainless steel water line.
After connecting the valve end of the water line, purge the line and supply plumbing of air by opening the valve at the end of the connected supply line in a small pail or container.
When connecting the braided water line use only hand tightening. These connections use small o-rings seals that can be torn easily with too much force. Do not use a wrench on these connections!
Prior to connecting the line, take a moment to apply a bit of o-ring lubricant to the seals prior to tightening.
- Install the actuator access splash cover and mud guard.
Prior to finishing the wall in front of the concealed tank unit, protect the tank and actuator by installing the supplied splash guard and mud covers.
Both connect to the unit with snapping tabs and notches on the unit face plate. Install the splash guard first by inserting the lower tabs then swinging the top in until the top tabs lock.
With the splash guard in place, install the mud cover. The mud cover locks onto slots on the front of the front plastic faceplate (see diagram to the right).
- Finish wall over unit.
With the unit securely fastened in the wall cavity and the supply and waste plumbing connected, complete the construction and finishing of the wall over the concealed carrier unit.
Geberit recommends sheathing the wall over a concealed toilet tank wall unit with cement board or similar moisture-resistant sheathing. We used cement board and finished with tile.
To finish the wall over the in-wall toilet tank and frame we used the same white subway tiles we used for the shower.
- Install the plumbing connections and mount the toilet bowl.
With the wall finished, the next job is to connect the toilet bowl to the wall and plumbing.
Before we can hang the toilet, we need to insert the plumbing adaptors and seals that will attach to the toilet bowl.
Using the Geberit supplied plumbing connector set, we will install fittings for the flush water and waste connections. These fittings will need to be cut to the proper length depending on the toilet bowl you are using. Once cut, rubber seals connect to the fittings to form a seal with the toilet bowl.
To measure the fittings correctly, follow the instructions provided by the in-wall unit you are using. I found this installation video useful for accurately determining the proper fitting lengths. The toilet bowl install begins at the 4:10 mark of the video.
Measuring and cutting the plumbing connections is critical. Take your time with this step and make sure the tubing lengths are correct.
Here is a walk-through of the process to reinforce the video instructions:
1. Find the supplied plumbing connector set with inlet and outlet seals and connection hardware. Remove the protective yellow covers from the upper supply pipe (smaller) and the lower (larger) waste pipe. Apply the supplied lubricant to the inner seals of both pipes.
2. Attach the supplied rubber seals to the ends of both the smaller white flush connector and the larger black waste connector. Then, insert both connectors into the pipe openings in the wall with the seal ends out. Gently push them in as far as they will go. Mark both connectors at the level of the wall face with the marker. Remove both of the connectors.
3. Lubricate the porcelain connection ends at the back of the toilet. Spread the lubricant around the inside of the flush inlet (smaller opening) and the outside of the waste outlet (the larger opening).
4. Install the connectors to the toilet bowl for marking. Push the seal ends of the connectors into the toilet bowl. The flush inlet (smaller) connector should fit inside the toilet flush opening, and the waste outlet (larger) connector should fit over the toilet waste outlet.
5. After both fittings are fully engaged with the toilet bowl, mark both connector pipes at the level of the base of the back of the toilet bowl using a straight edge and marker. Then, remove both of the connector pipes.
6. Now you will have the two connector pipes with two marks on them. Use these marks to determine the cut-off point on the end (non-seal end) of the connector pipes.
Do this by:
1) Measuring the distance between the two marks on the pipe.
2) Add 1/8″ to this measured distance.
3) Mark the location of the above length measured from the non-seal end of the connector pipes.
4) Cut the pipes at this mark.
Example: You pipe has two marks that are 3″ between. Add 1/8″ to get 3 1/8″. Measure 3 1/8″ from the non-seal end of the pipe and cut there.
7. Cut the supply and waste pipes as outlined above. Consider using a method of cutting the pipes that will create a square, flat, cut end. If using a hand saw, consider using a miter box. Once cut, smooth the cut edge of the pipe at a 45-degree angle with a file or sanding block. Be sure to remove burrs from the cut pipe as they can damage the rubber seals the pipes will pass through when installing them.
8. Lubricated and install both connector pipes into the wall unit, gently pushing them in as far as they will go.
9. Prepare to install the toilet bowl. Adjust the mounting threaded rods to the proper depth by measuring the thickness of the toilet mounting flange and adding 7/8″ – 1″ to the flange thickness. If using the foam pad (sound guard) behind the toilet, install it now.
10. Install the toilet by lifting it to align the toilet openings with the connector pipes from the carrier and then pushing the toilet into the connectors. When the toilet is seated and to the wall, install the leveling washers, the steel washers and then the nuts over the mounting rods. Before tightening the mounting bolts fully, check the level of the toilet bowl and make adjustments as necessary using the leveling washers. Once level, tighten the mounting nuts and cap with the supplied plastic covers.
- Caulk toilet bowl and mount toilet seat.
After the toilet bowl is securely mounted to the wall, caulk the interface between the bowl and wall with silicone or elastomeric sealant (Lexel).
If using an elastomeric sealant (like Lexel), working very quickly to smooth, as this product sets up very quickly and has a very short working time before the surface becomes tacky and difficult to smooth.
For a clean caulk line, first apply painters tape, leaving a gap to apply the caulk. Apply caulk and smooth with finger or tool, and then remove the tape.
Next mount a toilet seat designed to fit the toilet bowl you are using. I chose the soft-closing Toto SS204 toilet seat with cover which I highly recommend.
Mount the toilet seat using supplied nuts and bolts (nylon in the case of the Toto seat) after aligning the seat with the bowl.
- Assemble actuator components and cover.
Remove the plaster cover from the actuator access. Snap the walls of the mudguard so they are flush with the finished bathroom wall face. Do this by first using a utility knife to cut the edges of the mud guard walls back to the desired breaking depth.
Next flush the flexible water supply line to remove air in the supply plumbing (if not already done). Do so by disconnecting the distal end of the supply line (connected the tank) and opening the supply valve to purge air. Use a small cup to flush to catch any water coming out.
Once flushed, connect the flexible water supply tubing to the tank connection. Remember to tighten these connections only as they rely on a relatively small o-ring to seal. With the line connected and flushed, open the supply valve.
Then, install the flush components. First, install the actuator cam lever unit by snapping it into the access base edge lip and resting it on molded ridges on tank.
After the cam level unit is in place, install the white plastic actuator cover plate by inserting the tabs at the bottom and snapping the top tabs in place.
Next, install the black cover frame using the locking key pins located at the sides of the cover. Insert the key pins and turn to lock as illustrated on the frame.
With the cover frame installed, insert the flush control push rods into the access hole in the cam lever unit. Install one push rod for each flush controller. These rods are notched to allow sizing to match the wall depth. To change the length of these rods, simply break the rod at the appropriate notch for the size you need to match your wall depth.
With the control rods properly sized, install them by passing them through the holes in the actuator frame and dust cover and into the actuator “gear box” cams. Some control rods are sized and colored differently for each flush actuator (check with your install literature). Once passed into the actuator gearbox, turn the control rods to lock in place.
Test the flushing function by pushing on each control rod – it should initiate a flush cycle. With the actuator control rods assembled, locked and working properly, finish the actuator assembly by installing the actuator cover.
For the Geberit unit, the cover is installed by first pushing the base of the cover against the wall and sliding up to engage the two plastic tabs with the rounded metal springs at the base of the black actuator frame. Once both of the bottom cover tabs are engaged with the frame spring, push the cover up and over the top of the frame edge to lock in place.
- Enjoy your new wall hung, concealed tank toilet!