1 · The work order
Read the work order. The simulation stays locked for now. First you need to understand what the job is.
Work order no. 2026-B-084
Your task
Find out which mistakes were made during installation and explain how build-up height, slope and waterproofing are connected. Plan the correct build-up and the checks on site. At the end, explain to the Schneider family in three sentences what happened.
2 · Your prediction
Commit to an answer before you use the simulation. Wrong predictions are allowed. They are exactly what you learn the most from.
3 · Explore
Work in pairs: one person operates the simulation, the other takes notes. Tasks tick off automatically as soon as you reach the required state. Time-lapse: while the shower runs, one second equals about one week of use.
- E1 · Normal condition. Set standard conditions: build-up height 105 mm, slope 2.0 %, waterproofing 100 %. Turn the shower on. Watch drainage and moisture.
- E2 · Find the limit. What is the minimum slope at which water from a running shower just reaches the drain without overflowing?%
- E3 · Recreate the damage. Set up the Schneider case: build-up height 85 mm, slope 0.5 %, waterproofing 40 %. Let the shower run for weeks. When does anyone notice the damage?
- E4 · Counter-check. At full build-up height, set an excessive slope of 3.0 %. What does that mean for the tiling and for the user?
4 · Formulate the rule
First compare your prediction with what the simulation showed. Then write the rules yourself. You will only see the model rule afterwards.
| Question | Your prediction | The simulation shows |
|---|
Model rule
Slope: A level-access shower needs a continuous slope of 1.5 to 2.0 % towards the drain. Only then does surface water drain reliably without backing up. Too much slope (above approx. 2.5 %) causes a slip hazard, trip edges and a lot of cutting waste with large-format tiles.
Waterproofing: Tiles and cement grout are not waterproof by design. Underneath, there must be continuous bonded waterproofing, with the sealing collar embedded without voids and undamaged sealing tapes. Every defect lets water into the screed and insulation with every shower. The damage only becomes visible after weeks, and by then it is permanent.
Build-up height: The drain with trap, the pipe fall and the minimum screed cover all need space. If the build-up height is too low, people save on slope or on screed cover. The results are overflow, cracks above the pipe and creeping moisture damage. Solution: choose a flat renovation drain system; never save on slope or waterproofing.
Where does your rule differ? Add to it above before you move on.
5 · To the workbench
Now the real component counts. The simulation is locked, because it does not replace a single minute of craft.
a) Work plan: put the steps in the right order
b) Measure on the practice build-up or on site
Measure and enter the values. No build-up available? Your teacher will give you values.
| Measurement | Value |
|---|
6 · Feedback
Your real measurements go back into the simulation. Would this build-up survive daily showering?
| Measurement | Value | Rating |
|---|
"Check" loads the value into the simulation, sets all other values to target, rebuilds the shower area and starts the shower. That way you see the effect of exactly this one value.
Solution: work order no. 2026-B-084
Cause: The build-up height of 85 mm was not enough for the chosen drain system. To save height, the slope was reduced to 0.5 %. Water backs up and overflows. In addition, the sealing collar of the linear drain was embedded with voids and creases, and the sealing tape in the wall corner was damaged during tiling. For months, water seeped unnoticed into the screed and insulation with every shower.
Measures: Remove the tiles and the soaked sloped screed in the shower area completely. Dry out the floor structure with technical drying equipment. Install a flat renovation drain system (e.g. from 60 mm installation height) with sufficient drainage capacity. Lay new sloped screed at 2.0 %. Apply continuous bonded waterproofing to DIN 18534 with correctly integrated sealing collar and sealing tapes. Re-tile.
Customer explanation (example): "During the renovation, there wasn't enough height in the floor, so the shower was built with too little slope and the water runs into the bathroom. On top of that, the waterproofing under the tiles is leaking at the drain, so for months water has been seeping unnoticed into the floor and down to the ceiling below. We need to open up the shower floor, dry out the screed and ceiling, and rebuild the shower with a special flat drain and a watertight waterproofing layer."
Learning record
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Simulation: section through the shower floor
Simplified teaching model · slope exaggerated in the drawing · time-lapse: 1 s of showering ≈ 1 week of use