PPR, copper or stainless steel pipes?

Side-by-side comparison

The table sets out what PUB's Stipulation of Standards and Requirements for Water Fittings (PUB S&R) and HDB's plumbing works guidelines say about each material. Neither source rates them, so the table does not either.

Laying, installing or replacing water pipes is water service plumbing work. PUB says regulated water service work must be done by a PUB Licensed Plumber, apart from a short list of simple works covered below. Prices and lifespans are left out: price depends on the job, and no source here compares lifespans.

Should you choose a PPR pipe, copper or stainless steel?

No source here says one material lasts longer or leaks less than the others. PUB S&R is a supply standard: it sets the tests each material must pass, but it does not rank them. PUB states that no water fitting, pipes and pipe fittings included, can be supplied, displayed, offered or advertised for use in water service installations in Singapore unless it has been tested to PUB S&R.

So the choice rests on three things: your plumber's advice for your flat and where each pipe runs, whether a line carries hot or cold water, and how the pipes will be jointed. Talk to licensed plumbers before you settle on one.

Hot water lines

PUB S&R sets two rules worth knowing for hot water runs. Non-metallic materials in contact with water must comply with SS 375 or BS 6920, and for hot water use they are tested at the maximum temperature the manufacturer declares. Plastic pipes such as PPR are non-metallic. Water fittings must also be marked with the manufacturer's identification and, where applicable, a colour code for hot and cold water supply.

Before work starts, ask what maximum temperature the pipe is declared for and whether its marking suits a hot line. Ask how it will connect to your water heater. If your plumber suggests copper or a stainless steel pipe instead, ask which standard it is tested to. If the heater is also being replaced, see water heater installation.

Replacing pipes in an HDB flat

Plumbing works under HDB's renovation guidelines need no HDB permit but are subject to HDB's technical terms and conditions. HDB names replacing an existing PVC water pipe with copper or stainless steel, which must comply with PUB requirements. So copper pipe replacement of an old PVC line is a named option; PPR is not named, so ask your plumber. HDB says any water pipe work must be done by a PUB Licensed Plumber.

HDB also limits where pipes go. Pipes must not be embedded in the floor slab: for concealed water pipes in floor finishes or walls, the slab and wall must not be tampered with. HDB discourages such work because it may cause water leakage to the unit below if not properly done. Pipes enclosed with lightweight non-combustible materials need a removable access opening of at least 600mm x 600mm for inspection and maintenance.

PUB's simple plumbing works list lets a handyman without a PUB licence replace or remove any pipe between a stop valve and an instantaneous water heater, plus certain flexible hoses, such as a shower hose. Any other water pipe, concealed or exposed, is PUB Licensed Plumber work. See what needs a licensed plumber for the full split.

Questions to ask the plumber

The price depends on the job, so get a written quote for your flat and ask:

• Which material do you suggest for each run, and why?
• Which standard is the pipe tested to, and what marking will it carry?
• How will the joints be made?
• Will the runs be exposed or concealed, and where will the access panels go?
• Does the price include removing the old pipes, making good and testing?
• If the repiping follows a leak, is finding the source part of the job?

If water is already escaping, deal with that first: see leak repair.

Which one should you choose?

There is no winner among the three. Decide with a PUB Licensed Plumber who has seen your pipes, after hearing which material they suggest for each run and why. You can find Licensed Plumbers through PUB's online listings, the Singapore Plumbing Society or your Town Council. Then compare quotes from plumbers on the same material and the same scope, and use the plumbing cost estimator to plan your budget.

Questions