By Quality Sanitary Ware Team
On an apartment block or hotel, one shower mixer model is usually repeated across dozens or hundreds of bathrooms. If it suits the water supply, the plumbers and the maintenance team, nobody notices it. If it does not, the same complaint arrives from every unit at once, usually after handover, when fixing it is slow and expensive.
This article sets out what developers, architects and project managers in Ghana should agree before placing a bulk order for showers and mixers. We write from the supply side: we make shower sets and mixers for project buyers, and these are the problems we see most often when a specification is settled on appearance alone.
1. Start with how water actually reaches the bathroom
Many bathroom fittings are designed and tested around a reasonably steady pressurised supply. The European standard for mechanical mixing valves, EN 817, sets an operating range of more than 0.05 MPa (0.5 bar) dynamic pressure and up to 1.0 MPa (10 bar) static pressure, with 0.1–0.5 MPa (1–5 bar) as the recommended range. The European standard for thermostatic mixing valves, EN 1111, uses the same recommended range [1][2].
Ghanaian buildings often do not receive that kind of supply directly from the mains. Ghana Water Limited (GWL) has said that, because treatment capacity in Accra is insufficient for demand, it rations supply so that most households in the Greater Accra Metropolis receive water three to five days a week [3]. GWL rationing timetables published for parts of Accra advise residents to store water ahead of supply periods [4]. In practice, most projects therefore rely on ground or overhead storage tanks, booster pumps, boreholes, or a combination of these.
That has direct consequences for shower selection:
Gravity-fed overhead tanks give low pressure on upper floors. As a rule of thumb, each metre of height between the water level in the tank and the shower outlet gives roughly 0.1 bar of static pressure. A top-floor flat with a tank only two or three metres above the shower head may be close to, or below, the 0.5 bar lower limit that EN 817 uses for mixers. A large rain-shower head or a thermostatic valve that needs a balanced supply may perform poorly there, even if it works perfectly in a showroom.
Pumped systems can swing the other way. Lower floors of a pumped building can see high pressure when demand is low, and pressure can fall when many outlets open together in the morning. Ask the building services engineer for the expected minimum and maximum pressure at the highest and lowest bathrooms, and whether pressure-reducing valves are planned.
Hot and cold supplies should be similar. Single-lever and thermostatic mixers work best when hot and cold arrive at comparable pressures. A cold supply from a pumped main and a hot supply from a gravity-fed heater can make temperature control difficult.
So the first item to settle is not the shower style but the design pressure range at the outlets, floor by floor. Give it to the supplier in writing and ask which models suit it.
2. Plan for the power supply behind the water
Booster pumps and electric water heaters need electricity, and Ghana's supply has been interrupted at times. In June 2024, for example, the Electricity Company of Ghana and the Ghana Grid Company announced load-shedding, with power cuts expected to last at least three weeks, because of reduced gas supplies from Nigeria [5].
Two practical points follow. First, decide what happens to the showers when the pump stops: does the building fall back on gravity supply from the roof tank, and will the chosen shower heads still give a usable flow at that lower pressure? Second, for hotels in particular, match the hot water strategy (central heaters, unit heaters, solar water heating or heat pumps) to standby power and to the mixer type. A thermostatic mixer cannot deliver warm water if the heater has been off for hours.
Hotel operators should also keep stored hot water hot. The World Health Organization advises that hot water be kept above 50 °C, which requires water leaving the heating unit to be at or above 60 °C, and recommends flushing unused taps weekly to reduce stagnation [6]. That is relevant to mixer choice: when stored water is that hot, guests need reliable temperature control, and thermostatic or properly limited mixers become a safety issue, not only a comfort feature. EN 1111 itself notes that where thermostatic valves provide anti-scald protection for children, elderly or disabled people, the mixed temperature should be set to a suitable bathing temperature of around 38 °C [2].
3. Test the water, not just the pipework
Part 30 of the Ghana Building Code covers the design, installation, use and maintenance of plumbing components. A review of the code prepared under Ghana's National Adaptation Plan process notes that it assumes a constant water supply [7]. Developers therefore have to plan for real site conditions themselves, and water quality is one of them.
Many developments draw some or all of their water from boreholes. Studies in Greater Accra have found borehole water that is acidic, and in one study of 22 boreholes in Taifa total hardness ranged from 66.7 to 390 mg/l [8]. An earlier study of water in the Accra plains reported iron above the WHO-recommended 0.3 mg/l in 70% of boreholes sampled [9]. WHO notes that water with hardness above about 200 mg/l may cause scale in pipework and tanks, and that heating hard water forms calcium carbonate deposits [10]. Tanks and long pipe runs can also carry sediment.
For showers and mixers this means:
Test the water before choosing the fittings. A basic laboratory analysis of the actual source (hardness, iron, pH and turbidity) costs little compared with replacing clogged fittings across a building.
Treat at building level where needed. Sediment filtration, and softening or iron removal where tests justify it, protect every fitting downstream and are easier to maintain than dozens of point-of-use fixes.
Choose fittings that tolerate deposits. Shower heads with flexible rubber nozzles that can be wiped clean, inlet filters on mixers, and cartridges that can be removed without special tools all reduce maintenance time.
Choose finishes with cleaning in mind. In hard-water areas, finishes on which white limescale is less visible, or which tolerate regular cleaning, keep bathrooms presentable for longer. Agree the cleaning products housekeeping will use, since harsh descalers can damage some coatings.
Coastal sites such as Accra, Tema, Takoradi and Cape Coast add salt-laden air and constant humidity. Ask for corrosion test evidence on finishes, such as neutral salt spray testing to ISO 9227. ISO itself notes that salt spray tests are not meant to rank materials or predict long-term corrosion resistance [11], so treat such reports as a minimum check, and a sample kept in a real bathroom for some weeks as better evidence.
4. Agree threads and connections on paper
Connection mismatches are among the most common and avoidable problems on imported fittings. Two families of pipe thread are widely used:
BSP parallel threads (G threads) to ISO 228-1. These are parallel threads used for the mechanical assembly of fittings and valves. They do not seal on the thread itself; a seal is made by compressing a washer or face outside the thread [12].
NPT tapered threads to ASME B1.20.1. These are tapered American threads that are tightened into each other and normally need a sealant to make the joint pressure-tight [13].
A G1/2 fitting and a 1/2-inch NPT fitting can look alike and may even engage for a turn or two, but they are not designed to seal together. Forcing them, or relying on extra tape, leads to slow leaks inside walls and ceilings.
Before ordering, confirm in writing:
the thread standard and size of the wall points, mixer inlets, shower hose and shower head (G1/2 is common for hose and head connections in many markets, but check);
the centre distance between hot and cold inlets on exposed mixers, and whether the eccentric connectors supplied cover the spacing your plumbers will actually build;
the outlet orientation: wall-facing supplies and upward-facing exposed pipes need different shower sets, even when the visible parts look the same;
the depth and dimensions of any concealed valve body, so that wall build-up and tiling are planned around it.
Give your plumbing contractor the supplier's dimensioned drawings early, and ask them to sign off the connections against the actual first-fix layout.
5. Think about who will repair it
A building will need cartridges, washers, hoses and shower heads replaced over its life. Before standardising a model, ask:
Can a typical local plumber diagnose and replace the cartridge with ordinary tools?
Are the cartridge size and type stated on the specification sheet, and are compatible spares available in Ghana, or only from the original supplier?
Will the supplier supply spare parts with the order and identify them by model and revision?
On multi-unit projects, order a stock of the parts most likely to wear (cartridges, diverters, hoses, hand showers and seals) with the main order and keep them on site with labelled drawings. Standardising on one or two mixer models per building makes this far easier for the facility manager.
6. Approve a sample before mass production
This is the step we insist on, and the one that most often prevents problems. From our experience supplying project orders to Africa and the Middle East, a sample that is only looked at in an office is not enough. Before mass production, we ask buyers to confirm the local water pressure, the thread standard (G1/2 or NPT) and how the cartridge should function, not just the finish and shape.
A useful sample review covers:
Installation. Fit the sample in a mock-up bathroom, on the real wall points, by the plumber who will do the project.
Function at real pressure. Run it on the building's actual supply, ideally on the floor with the lowest pressure. Check flow, temperature control, diverter operation, and drips after closing.
Cartridge behaviour. Confirm the handle travel, temperature range and any temperature stop the project needs, and that the cartridge type matches the specification sheet.
Finish and packaging. Check coating, markings and the contents of each box against the order (for example, whether a hand shower, hose and bracket are included).
Records. Photograph and keep the approved sample, and write its model reference and revision into the purchase order.
When the bulk order arrives, check a selection of cartons against the approved sample and specification before installation starts. Problems found at the warehouse cost far less than problems found after tiling. For phased projects, label deliveries by room type and configuration so site teams do not mix up similar-looking sets. We have published a more detailed checklist for hotel and apartment shower set specifications that some project teams use to organise this.
7. Check documents, then check again on site
Ask suppliers for the documents behind any claim: test reports to the standards named in the specification (for example EN 817 for mechanical mixers or EN 1111 for thermostatic mixers), the edition and the laboratory, and any materials or drinking-water contact information required by the project's design team. Note that EN 817 and EN 1111 both state that their tests are type tests (laboratory tests on a design), not quality-control tests on each production batch [1][2]. A test report on a model is useful evidence, but it does not replace checking the goods you receive. Both standards have also been revised recently, so confirm which edition a report refers to.
A short pre-order checklist
Before signing off a bulk order for showers and mixers, the project team should be able to answer yes to the following:
We know the minimum and maximum water pressure at the highest and lowest bathrooms, including during pump outages.
The hot and cold supply arrangement suits the chosen mixer type.
The water source has been tested, and filtration or treatment has been decided.
The thread standard, inlet centres, outlet orientation and concealed body dimensions are confirmed on drawings.
Local plumbers can install and service the mixer, and spare cartridges and seals are identified and ordered.
A sample has been installed and tested on site, and the approved sample is recorded in the purchase order.
Test reports have been reviewed, and arrival inspection against the sample is planned.
None of these steps is complicated, but they need to happen before the purchase order, not after the first tenant complaint. With variable pressure, stored water, varying water quality and occasional power cuts, getting the specification right at the start is one of the cheapest ways to protect a Ghanaian building's long-term value.
Sources
CEN, EN 817:2008, Sanitary tapware – Mechanical mixing valves (PN 10) – General technical specifications, scope and Table 1 (preview). https://cdn.standards.iteh.ai/samples/23018/28a27e01dbb54e62a0b02eea2b053b6e/SIST-EN-817-2009.pdf
CEN, EN 1111:2017, Sanitary tapware – Thermostatic mixing valves (PN 10) – General technical specification, scope and Table 1 (preview). https://cdn.standards.iteh.ai/samples/58726/f9ad074569ab42b0b30c9f2d59e83a0d/SIST-EN-1111-2017.pdf
Asaase Radio, "GWL launches 24-month recovery plan to address water challenges…", 21 October 2025. https://asaaseradio.com/gwl-launches-24-month-recovery-plan-to-address-water-challenges-calls-for-support-to-dredge-major-intake-points/
Citi Newsroom, "GWL releases water rationing timetable for Teshie, Nungua and surrounding areas". https://www.citinewsroom.com/2026/01/gwl-releases-water-rationing-timetable-for-teshie-nungua-and-surrounding-areas/
BBC News, "Ghana braces for three weeks of power cuts", 14 June 2024. https://www.bbc.com/news/articles/cw88xx325n7o
World Health Organization, "Legionellosis" fact sheet. https://www.who.int/news-room/fact-sheets/detail/legionellosis
EPA Ghana / National Adaptation Plan, "A Review of Ghana's Building Codes and Standards", section 6.2. http://ghclimatevulnerabilityhub.com/epa/system/docus/6a9f625828916_BuildingCodesBackUp.pdf
Nyarko A.A., "Assessment of Groundwater Quality and Urban Water Provision: A Case of Taifa Township in the Ga-East District of the Greater Accra Region, Ghana", MSc thesis, KNUST, 2008. https://ir.knust.edu.gh/server/api/core/bitstreams/7e3c8661-1ed7-48d7-ad4b-7cb2e97539eb/content
Botchway C.A., Ansa-Asare O.D., Antwi L.A., "Natural fluoride and trace metal levels of ground and surface waters in the Greater Accra region of Ghana", West African Journal of Medicine, 1996 (abstract, PubMed 9020597). https://pubmed.ncbi.nlm.nih.gov/9020597
World Health Organization, Hardness in Drinking-water, background document for the Guidelines for Drinking-water Quality, and chemical fact sheet. https://cdn.who.int/media/docs/default-source/wash-documents/wash-chemicals/hardness-bd.pdf ; https://www.who.int/docs/default-source/wash-documents/wash-chemicals/hardness-chemical-fact-sheet.pdf
ISO, ISO 9227:2017, Corrosion tests in artificial atmospheres – Salt spray tests, abstract (since revised as ISO 9227:2022). https://www.iso.org/standard/63543.html
ISO 228-1, Pipe threads where pressure-tight joints are not made on the threads – Part 1, scope (EN ISO 228-1:2003 preview). https://cdn.standards.iteh.ai/samples/20061/68e576f6dea340efaa4764099eb13e64/SIST-EN-ISO-228-1-2003.pdf
ASME B1.20.1, Pipe Threads, General Purpose (Inch), scope (preview). https://asme.stdlink.com/preview/2024/07/11/68269ddc39d948799af482099cc7fbeb.pdf
About the author
The Quality Sanitary Ware Team works for Quality Sanitary Ware, a manufacturer of shower sets, shower heads and mixers in Ningbo, China, founded in 2011. For 15 years, the team has supplied wholesale and OEM/ODM buyers across Africa, the Middle East and the GCC, and works with project teams on sampling, connection checks and specifications before bulk production. More at https://qualitysanitaryware.com/.
