Bathroom renovation: 10 points that prevent leaks (with a detailed budget)

Budget example (standard 5–8 m² bathroom in Luxembourg)

A practical benchmark for a typical project (removal + rebuild + finishes).

Labour (multiple trades)

• Around €12,500
• Estimated duration: 15–20 working days (drying times, complexity, access)

“Structural/gros œuvre” materials (networks + substrate + prep)

• Around €2,500–€3,000
• Typically includes:
• plumbing (water supply + drainage, fittings, traps)
• electrical (cables, boxes, protection, outlets, lighting points)
• waterproofing (shower zones/corners/junctions)
• screed/levelling (ragréage)
• wall straightening, repair compounds, consumables

Finishing materials (depends on the selected range)

Separate budget for:

• tiles + adhesive + grout
• wall-hung WC such as Geberit (frame + flush plate + bowl)
• shower base or tiled shower + glass screen + channel/trap
• taps/mixers (shower + basin)
• vanity unit + mirror
• accessories and finishing (silicone, profiles, etc.)

Where to buy (common options)

Batipro, Hornbach, Leroy Merlin, Globus Baumarkt, X2O, Reuter.

Realistic schedule (15–20 days) with control points

1. Protection + removal (1–2 days)
2. Plumbing + drainage (2–4 days) + leak and slope tests
3. Electrical + ventilation (1–2 days)
4. Substrate: walls + floor (flatness) (2–4 days)
5. Waterproofing critical areas (1 day)
6. Tiling walls/floor (3–6 days)
7. Grout + silicone (1–2 days)
8. Install fixtures (2–3 days) + tests
9. Finishing + final cleaning (1 day)
10. Handover (0.5 day): shower/drain test + visual check

The 10 technical points that prevent leaks

1. Moisture/substrate assessment before buying materials
2. Flatness: wavy surfaces will show through tiles
3. Drain slopes: wrong slope = slow drain + smells
4. Waterproofing shower/corners/junctions: no shortcuts
5. Ventilation: otherwise mould appears quickly
6. Large-format tiles require higher flatness tolerance
7. Clean grout + silicone in critical zones
8. Maintenance access (trap, access panels if needed)
9. Proper electrical work (lighting, mirror, sockets)
10. Final handover with water test + raking-light inspection

Budget tip that really works

Keeping water supply/drainage points in the same place usually reduces cost, risk, and timeline.

Questions to ask your contractor

• What waterproofing system is used, and where exactly?
• How are corners, pipe penetrations, and wall/floor junctions treated?
• Are removal and disposal included?
• What drying times are planned before tiling and grouting?