The wall-hung toilet has become standard in renovation. Fitting is not so complicated — but 3 mistakes come back systematically. Here is the complete guide: choosing the support frame, fitting it, connecting, finishing.
Choosing the right support frame
For 95% of cases, the Geberit Duofix Sigma 112 cm is the right choice: compatible with all Sigma plates (10, 20, 50, 70), 6/3L cistern, robust 400 kg.
Special cases:
- Reduced height (under a window) → Duofix 82 cm
- Child's toilet at home → Duofix with adjustable seat height 23-44 cm
- Plasterboard partition only → fix the frame firmly to the metal studs at two points + chemical anchoring to the floor
Mistake no. 1: the seat height
The classic mistake: fitting at 40 cm (NF standard). That is too low for adults. Recommended height: 43-45 cm (measured from the finished floor to the seat).
Check the height AFTER laying the tiles — not before. The screed + adhesive + tile easily represents 4-5 cm.
Mistake no. 2: the waste connection
The ø100 PVC bend must have a minimum slope of 1% (1 cm per metre). Too low = frequent blockages. Too high = amplified drainage noise.
Cut the pipe flush with the frame and use the Geberit rubber sleeve, never PVC glue directly on the pan waste — the pan must be able to move 2-3 mm without strain.
Mistake no. 3: tightening the threaded rods
The 2 threaded rods holding the pan are tightened with a torque wrench, 18 Nm maximum. Too tight = cracking of the ceramic 6 months later.
Use the ringed Geberit nuts (supplied with the frame) and NOT standard nuts — the ring absorbs the micro-movements.
Choosing the flush plate
Sigma 20: best-selling, timeless design, dual flush, plate with dual finish (polished chrome + matt chrome).
Sigma 50: higher-end, black glass or wood finish (oak / walnut / off-white). Stunning on a plain wall.
Sigma 70: the most design-led, plate flush with the wall, brushed metal finish.
