Concealed pipe leak
A concealed pipe is a water pipe hidden inside a wall or under the floor tiles, and when it leaks you see a damp wall patch, bubbling paint, or a water meter that keeps moving with every tap off. In HDB flats the usual fix is to stop using the hidden pipe and run a new exposed pipe along the wall, instead of hacking to reach it.
Typical price
$250–$600one short section, excludes retilingTypical job time
3–6 hours for one section; 1–2 days for several
Estimate, confirm on WhatsApp
PUB rule: this work must be done by a PUB Licensed Plumber. Since 2018 it is an offence to engage an unlicensed plumber for it. You can check any plumber on PUB's Licensed Plumber Directory.What needs a licensed plumber
Signs to look for
- A damp patch on a wall that never dries, often low down near the kitchen or bathroom.
- Paint that bubbles, flakes or turns powdery along one wall.
- The water meter keeps moving after you turn off every tap and appliance.
- Mould or a musty smell along one wall or in a cabinet against it.
- A stain on the ceiling of the flat below, or on the wall of the unit next door.
- A higher water bill with no change in use.
Common causes
- Old pipes. Many older HDB flats still have their original water pipes concealed in the walls, now decades old.
- Corrosion from the outside, where a metal pipe sits in damp plaster or concrete.
- A joint inside the wall that has worked loose or perished.
- A nail, screw or drill bit through the pipe during renovation or when putting up shelves.
- Pipes laid in the floor screed that crack when tiles are hacked or relaid nearby.
Before you call
Safe things to try first
- Do a meter test. Turn off every tap and appliance, read the meter, and check again after 30 to 60 minutes. Any movement means a leak after the meter.
- If your flat has a stop valve inside, close it and repeat the test. If the meter still moves, the leak is on the pipe between the meter and that valve.
- Note where the damp patch is and whether it changes when you use a particular tap. Take dated photos so you can see whether it is spreading.
- Do not drill into or hack the wall to look for the pipe yourself.
Stop and call if
- The meter is moving fast, or the damp patch is spreading by the hour.
- Water is reaching power points or the DB box.
- Your downstairs neighbour reports a new ceiling stain.
- The wall plaster feels soft or is starting to fall off.
What we do
- 1Confirm there is a leak with a meter test, then close valves in turn to work out which pipe run is leaking.
- 2Pressure-test the suspect run and take moisture readings on the wall to narrow down the spot without opening anything.
- 3Explain the options: abandon the concealed run and replace it with exposed pipe, or open the wall to repair the original pipe, with the cost and mess of each.
- 4Install the new pipe along the wall or ceiling line with proper clips, connect it to the taps and points it serves, and cap off the old concealed section. This is water service work and must be done by a PUB Licensed Plumber.
- 5Re-check the meter with every tap closed to confirm the leak has stopped, and tell you how long the wall needs to dry before repainting.
How much it costs
Most concealed pipe leak jobs in Singapore cost $250–$600 (one short section, excludes retiling). This is an estimate; the final price is confirmed on WhatsApp or on site before work starts.
- Leak detection to locate the concealed leak$120–$350
- Reroute one short section as exposed pipe$250–$600
- Reroute several sections$1,000–$2,500
- Inspection fee if no repair goes ahead$50–$120
HDB, condo and landed
HDB
PUB maintains the supply up to and including the meter. Everything after it, including pipes concealed in your walls, is the owner's to repair. HDB does not allow hacking of structural walls, so a concealed pipe in a structural wall is normally abandoned and replaced with exposed piping rather than dug out.
Condo
Pipes inside your unit are usually your responsibility. Check the by-laws before any hacking, and get the managing agent's approval if the work touches common property or involves noisy works.
Landed
You own every pipe from the PUB meter at the gate. Concealed leaks can be in walls on any floor or in the underground line, so a proper detection visit saves digging in the wrong place.
Concealed pipe leak: common questions
What is a concealed pipe?
A water pipe built into a wall, laid in the floor screed or boxed in, so you cannot see it, instead of running exposed along the wall. Many older HDB flats still have their original water pipes concealed in the walls. When one leaks, the water soaks through plaster or tiles first, so the first sign is usually a damp patch, not a drip.
How do I tell a concealed pipe leak from a waterproofing leak?
A pipe leaks all the time, so the meter moves even when nobody uses water. A waterproofing leak only shows when the bathroom floor gets wet, and the meter stays still. A damp patch that appears only after showers points to waterproofing.
Why not just hack the wall and fix the original pipe?
You can in some walls, but it means hacking tiles or plaster, finding matching tiles, and the rest of the old pipe may leak somewhere else later. A new exposed run is usually faster, cleaner and easier to repair in future. In structural walls, HDB does not allow hacking at all.
Will exposed pipes look untidy?
They are visible, but a neat run along the ceiling line or wall corners with matching clips is common in older HDB flats. Some owners box it in or paint it to match the wall.
Does HDB or PUB pay for a concealed pipe leak?
Generally no. PUB looks after the supply up to and including the meter. Pipes after the meter, including those inside your walls, are the owner's responsibility. Ceiling leaks through the floor slab between flats follow a different HDB process.
Can I leave a small concealed leak for now?
Not for long. A concealed leak runs day and night, adds to your water bill, and can damage plaster, cabinets and the flat below. Get it located soon, even if the repair is scheduled later.
Get a price for concealed pipe leak
Send a photo or short video, your home type and postal code. We reply with a price range and the earliest slot.
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