Are “The Gap” Sensor-Flush Urinals from Roca living up to their promise?
This real-world comparison shows why ZeroFlush waterless urinals with the EnviroSeal operating system outperform siphonic systems – traditional urinals that use a siphon to remove wastewater from the bowl, even the best-rated 0.8 L models.
💧 Water Use: 0.8 Litres vs Zero
The Gap siphonic urinals use 0.8 litres per flush. At 100 uses/day, that’s over 20,800 litres/year per urinal.
ZeroFlush with EnviroSeal operates without water—no plumbing flush is needed. The urinal’s unique design allows for the separation and capture of urine without the use of water.
Real-world case: A high-traffic fast-food facility in Queensland reported persistent odour and hygiene issues despite using Roca’s 0.8L models.
🧰 Maintenance: Costly Cleaning vs Cartridge Simplicity
Roca’s system relies on laminar water flow and precise vacuum action.
But mats, debris or buildup disrupt that, requiring disassembly, descaling and intensive cleaning.
ZeroFlush with EnviroSeal does not have vacuum mechanics. It is just a simple trap cartridge that is changed a few times yearly.
🧼 Hygiene & Odour Risk
Struvite crystals, bacteria, and uric deposits were found coating the grate and porcelain trap at the Queensland site, causing ongoing odour and sanitation failures.
ZeroFlush with EnviroSeal: Stays dry, eliminating the environment for those deposits to form.
⚡ Phantom Flush & Sensor Failure
Roca’s concealed sensor behind the grate was vulnerable to mineral blockage. Flush cycles failed, and phantom triggers were reported.
ZeroFlush with EnviroSeal: No sensors = no misfires. No false flushes. No energy used.
🔧 Installation & Plumbing
The Gap: Requires ceiling-access water pipes, sensor wiring and calibration.
ZeroFlush with EnviroSeal: Installs on existing waste lines with no sensor system—30% quicker on average, providing a straightforward and hassle-free installation process.
💸 Long-Term Cost
At 0.8L/flush, water cost alone is A$183/year per unit (based on 100 uses/day).
Add cleaning, sensor faults and descaling – and the cost stacks up.
ZeroFlush with EnviroSeal requires no water, no flush repairs, and low labour. It offers the lowest cost of ownership over 10 years, ensuring significant long-term cost savings and financial security.
📘 Compliance & Odour Control
When mineralisation blocked the trap grate, the Queensland facility’s system lost its 75 mm water seal. Sewer gas leaked back into the bathroom.
ZeroFlush with EnviroSeal: Doesn’t rely on water seals. A dry trap ensures continuous odour control.
🧱 Cleaning Labour
Restoring one siphonic unit required:
- Enzymatic foaming agents
- Manual scrubbing
- Disassembly and sanitation of parts
ZeroFlush® with EnviroSeal: No descaling. No scrubbing. No plumbing disassembly.
🏅The Gap Sensor-Flush Urinals Green Ratings & Rebates
The Gap may only earn partial water-efficiency credits.
ZeroFlush® with EnviroSeal: Gets full rebates and full points toward Green Star, NABERS Water and LEED.
🌏 Guest Impressions
Blocked Roca urinals caused visible staining, odour and damage in the Queensland facility, despite regular cleaning.
ZeroFlush with EnviroSeal: Always dry. Always clear. Always performing.
✅ Summary: The Gap Sensor-Flush Urinals vs ZeroFlush® with EnviroSeal
| Feature | Roca “The Gap” Urinal | ZeroFlush® with EnviroSeal |
| Flush volume | 0.8 L | 0 L |
| Annual water use | 20,800 L | 0 L |
| Reported odour issues | Yes | Rare |
| Mineral risk | High | None |
| Cleaning effort | High | Low |
| Installation | Complex | Simple |
| Phantom flushes | Common | None |
| Sensor failure risk | High | None |
| Water rebates | Partial | Full |
| Guest hygiene perception | Low | High |
The Verdict: Who Really Outperforms?
A high-traffic Queensland site showed that even “efficient” siphonic urinals carry odour, labour, and hygiene risks.
ZeroFlush with EnviroSeal avoids all of them.
Zero water. Zero emissions. ZeroFlush. The smarter choice.
🔍 Download the Report
Want to see exactly what went wrong with the Gap Sensor-Flush Urinals in a high-traffic Queensland site?
This detailed technical report highlights the odour, maintenance and compliance issues owners faced firsthand.
Gary Mays, born and educated in Auckland, New Zealand, has called the Gold Coast, Queensland, Australia, home since 1986. Currently, the Executive Director at Whywait Plumbing Pty Ltd and Aquatemp Environmental Solutions Pty Ltd. He’s a licensed plumber with an impressive international business background in New Zealand, Australia, and Singapore. Gary is known for his vigorous advocacy in plumbing, water conservation, sustainability, and small business growth. He is an influential and forward-thinking leader, a frequent voice in modern media for his industry insights and deep dedication to ecological, environmental, and professional causes.
