An in wall toilet creates a clean, open bathroom while hiding bulky plumbing. By recessing the cistern into the wall cavity, you free up floor space and achieve a sleek, minimalist look. Systems such as the Geberit Sigma8 inwall cistern paired with a rimless tornado wall faced toilet pan show how modern design and smart engineering work together. The concealed cistern sits inside the wall, while the gloss white pan and push button remain visible and easy to clean. This guide walks through what you need, how to plan your layout, and the key steps to install an in wall toilet safely. You will also learn practical tips to prevent leaks, support weight correctly, and keep your bathroom looking sharp for years.
What Do You Need Before Installing an In Wall Toilet?
Essential Tools and Materials Checklist
Gather the right tools and materials before you start. You will need a tape measure, spirit level, pencil, stud finder, adjustable wrench, pipe wrench, drill with masonry and wood bits, hole saw, utility knife, and a hacksaw or pipe cutter. Prepare PEX or copper pipes for water, PVC pipes and fittings for waste, PTFE thread tape, pipe insulation, and silicone sealant. Have appropriate wall anchors, screws, and brackets for your wall type. Your main components include a concealed cistern and frame system, such as the Geberit Sigma8 inwall cistern, a compatible wall faced rimless tornado toilet pan, and a matching flush push button plate. Keep personal protective equipment handy: gloves, safety glasses, and hearing protection. This preparation prevents delays and mistakes.
Understanding Wall Frame Systems and Components
An in wall toilet relies on a robust frame system that holds the weight of the user and supports all visible parts. The concealed cistern, like the Geberit Sigma8 unit, mounts to a steel frame that fixes securely to the floor and studs. This frame carries the toilet bowl, flush plate, and pipe connections. The rimless tornado wall faced toilet pan bolts to the frame rather than the floor, creating a clean back-to-wall look. Inside the frame sit the inlet valve, flush valve, and outlet bend that connects to the waste pipe. The push button plate clips onto a service opening, allowing access for minor maintenance. Understanding how these parts interact helps you position everything correctly and avoid structural or plumbing issues.
Measuring Space and Planning Layout Properly
Careful planning ensures your in wall toilet fits comfortably and works well. First, locate existing water and waste lines. Measure the height, depth, and width of the wall cavity where the Geberit Sigma8 inwall cistern and frame will sit. Check for studs, pipes, or electrical cables with a stud finder to avoid clashes. Allow space for the rimless tornado wall faced toilet pan: note its dimensions, typically around 580x360x420mm, and leave clearance on both sides for cleaning and access. Plan the finished seat height, usually 400–450mm from the floor, and mark centre lines on the wall and floor. Confirm the frame depth does not exceed the wall thickness once tiled. Good layout planning prevents costly rework and ensures a balanced, modern appearance.
How Do You Install an In Wall Toilet Step by Step?
Installing the Concealed Cistern and Support Frame
Start by opening the wall where the in wall frame will sit, cutting carefully between studs. Assemble the support frame and concealed cistern according to the manufacturer’s manual, such as the Geberit Sigma8 installation guide. Position the frame on the marked centre line and adjust the legs to reach the correct finished seat height. Use a level to check both vertical and horizontal alignment. Fix the frame securely to the floor with expansion anchors and to the wall studs or masonry using the supplied brackets. Tighten all fixings so the structure feels rigid and does not move. Confirm that the service opening for the push button plate remains clear and accessible. Double-check measurements before you close any part of the wall.
Connecting Plumbing and Drainage Systems
With the frame secure, connect the water supply to the cistern inlet using approved fittings and PTFE tape on threaded joints. Follow local plumbing codes and, where required, fit an isolation valve for easy future maintenance. Connect the cistern outlet to the toilet outlet bend supplied with the system. Attach the waste pipe to the outlet, ensuring the correct fall, usually about 1:40, for reliable drainage. Test fit the rimless tornado wall faced toilet pan to confirm the pipe positions line up. Pressure-test the water supply and perform a basic leak test on the cistern connections while the wall is still open. Inspect every joint by sight and touch. Fix any leaks immediately before proceeding to close the wall and tile.
Mounting the Toilet Bowl and Flush Plate
After tiling and finishing the wall surface, fit the mounting sleeves and threaded rods that support the toilet bowl. Slide the rimless tornado wall faced toilet pan onto the rods, guiding the waste and flush connections into place. Use a level to check the pan sits straight, then tighten the nuts gradually and evenly to avoid stressing the ceramic. Apply a neat bead of sanitary-grade silicone around the base where it meets the tiles for a hygienic, sealed finish. Next, install the push button plate that matches the Geberit Sigma8 cistern. Clip or screw it into the service opening, connect the actuation rods or cables, and test both full and half flush functions. Confirm the bowl flushes cleanly and refills correctly.
What Are the Key Tips for a Successful Installation?
Ensuring Proper Alignment and Weight Support
Good alignment and strong support protect both the toilet and the wall. Always verify the frame stands perfectly plumb using a reliable spirit level. Recheck alignment after tightening anchors, as bolts can pull the frame slightly. Confirm the mounting height suits the users and complies with local standards, especially in accessible bathrooms. Use all fixing points provided on the Geberit Sigma8 frame and match them to solid structure: timber studs, steel framing, or masonry, not just plasterboard. Tighten the pan mounting bolts gradually and avoid overtightening, which can crack ceramic. If your wall construction feels weak, add extra noggings or blocking between studs before mounting the frame. This reinforcement spreads the load and ensures the toilet can safely support weight.
Preventing Leaks and Securing Waterproof Seals
Leak prevention starts with careful pipe work and continues through to final sealing. Wrap threaded fittings with PTFE tape, tighten them firmly, and avoid cross-threading. Use quality push-fit or compression fittings where compatible and follow the manufacturer’s torque guidance. Test the Geberit Sigma8 concealed cistern for leaks before you close the wall: fill, flush repeatedly, and inspect all joints. Around the shower or wet areas nearby, apply appropriate waterproof membranes and tapes as required by building codes. At the toilet, run a smooth bead of sanitary silicone around the rimless tornado wall faced pan where it meets the tiles. This seal stops water from mopping or splashes from seeping behind the pan. Recheck seals after a few days and touch up any gaps.
Conclusion
Installing an in wall toilet can transform a dated bathroom into a modern, space-saving retreat. A concealed system like the Geberit Sigma8 inwall cistern combined with a gloss white rimless tornado wall faced toilet pan delivers a sleek back-to-wall appearance and powerful, hygienic flushing. Success depends on planning the layout, measuring accurately, anchoring the frame properly, and checking every plumbing joint. Take your time with alignment and sealing to ensure long-term reliability and avoid hidden leaks. Many confident DIYers can complete the work, but local regulations may require a licensed plumber for water and drainage connections. With the right preparation and adherence to best practices, your new in wall toilet will look clean, perform well, and maximise precious floor space.