How to Find a Plumbing Leak and Detect Plumbing Problems

Plumbing leaks can be sneaky, causing damage long before you notice them. A small leak might seem harmless but, over time, it can lead to mould growth, structural damage and skyrocketing water bills.

That’s why knowing how to find leaks early is essential for homeowners.

Signs like water stains, musty odours, or an unexplained spike in your water bill could indicate a hidden leak. Sometimes, the problem isn’t just a dripping tap − it could be a slab leak, pipe corrosion or underground plumbing issues. The sooner you spot these problems, the easier (and cheaper) they are to fix.

In this guide, we’ll walk you through how to detect plumbing leaks, check for hidden issues, and know when to call in a professional. Let’s get started on protecting your home from water damage.

Common Signs of a Plumbing Leak

Plumbing leaks aren’t always obvious, but they leave behind clues if you know where to look. One of the most noticeable signs is an unexpected spike in your water bill − if you haven’t increased your usage but your bill keeps rising, there may be a hidden leak.

Another red flag is water stains on walls or ceilings. These often appear as brown or yellow patches and could indicate a slow leak behind the surface. Musty odours or mould growth are also signs of excess moisture, which could be coming from a leaking pipe.

Listen for the sound of running water when no taps are on − this could mean water is leaking somewhere out of sight. Low water pressure might suggest a pipe leak, while soft or damp spots on floors could indicate an issue beneath your home.

Outside, watch for unexplained puddles in your yard or overly green patches of grass − this may point to an underground leak. Catching these signs early can help prevent costly repairs and serious water damage.

How to Check for Hidden Water Leaks

Not all plumbing leaks are visible – some are hidden behind walls, under floors, or even underground. If you suspect a leak but can’t see it, try these simple methods to track it down:

• Check your water meter – Turn off all taps and appliances that use water, then check your meter. Wait 30 minutes without using water and check again. If the meter has changed, you likely have a hidden leak.
• Listen for unusual sounds – If you hear running water, hissing, or dripping when no taps or showers are on, a pipe may be leaking behind walls or under floors.
• Inspect walls and ceilings – Look for water stains, bubbling paint or warped plasterboard – these are all signs of moisture damage.
• Test your toilets – Drop food colouring into the toilet tank and wait 10 minutes. If the colour appears in the bowl, your toilet has a silent leak.
• Watch for mould or musty smells – Mould thrives in damp environments, so unexplained growth or persistent musty odours can indicate hidden moisture.

Finding leaks early helps prevent costly damage – if in doubt, call a professional plumber for an inspection.

How to Detect Pipe Damage and Corrosion

Pipes don’t last forever, and over time, they can corrode, weaken, and start leaking. Catching signs of damage early can prevent costly repairs and water damage. Here’s what to look for:

• Discoloured or rusty water – If your tap water looks brown, red, or has a metallic taste, your pipes may be corroding from the inside.
• Visible corrosion – Check exposed pipes under sinks, in basements, or near your water heater. Look for rust, flaking, or greenish-blue discolouration on copper pipes.
• Frequent leaks – If you’re constantly dealing with small leaks, your pipes may be deteriorating and prone to more serious damage.
• Low water pressure – A sudden or gradual drop in water pressure could mean mineral buildup or corrosion is restricting water flow inside your pipes.
• Strange noises – If you hear banging, gurgling or hissing from your pipes, it could be a sign of internal damage or trapped air from a leak.

If you notice these signs, it may be time to replace ageing pipes or call a plumber for an inspection.

Detecting Slab Leaks and Underground Plumbing Issues

Slab leaks and underground plumbing issues are some of the trickiest leaks to detect because they happen beneath your home’s foundation. Left unchecked, they can lead to severe structural damage and costly repairs.

One of the biggest warning signs of a slab leak is unexpected warm spots on your floor − this could indicate a hot water line leaking under the foundation. Cracks in your walls or flooring may also develop as water erodes the soil beneath your home, causing it to shift.

If you notice wet spots, puddles or excessive moisture around your home’s foundation, you might have an underground leak. Another sign is higher water bills without increased usage − if your water meter is running when no water is being used, you could have a hidden problem.

Outside, watch for lush green patches in your lawn or areas of sinking ground − this could indicate a leaking underground pipe. Because these leaks can be difficult to locate, calling a professional plumber with specialised leak detection equipment is often the best solution.

How to Prevent Plumbing Leaks

While plumbing leaks can cause serious damage, many can be prevented with regular maintenance and a few simple precautions.

Here’s how you can protect your home from unexpected leaks:

• Inspect pipes regularly – Check under sinks, around appliances, and in basements for signs of moisture, rust or small leaks before they become major issues.
• Monitor your water pressure – High water pressure can put stress on pipes, leading to leaks. Use a pressure gauge to ensure it stays between 40-60 psi. If it’s too high, install a pressure regulator.
• Avoid chemical drain cleaners – Harsh chemicals can weaken pipes over time. Use a drain snake or a natural mixture of baking soda and vinegar to clear clogs instead.
• Replace old or corroded pipes – Pipes degrade over time, especially in older homes. If you notice rust, discolouration, or frequent leaks, consider replacing them before they fail.
• Install leak detection devices – Smart leak detectors can alert you to hidden leaks before they cause serious damage.

By taking these steps, you can minimise the risk of costly plumbing problems and keep your home leak-free.

When to Call a Professional Plumber

Some plumbing leaks are easy to spot and fix, but others require expert attention. If you’ve noticed persistent water stains, mould growth or musty odours despite your best efforts to find the source, it’s time to call a professional.

Hidden leaks behind walls or under floors can cause structural damage, and a plumber has the tools to detect them without unnecessary destruction.

A sudden drop in water pressure or multiple slow drains could indicate a bigger problem, like a pipe blockage or an underground leak. If your water bill keeps climbing with no clear explanation, a qualified plumber can perform a thorough inspection to locate hidden leaks.

Serious issues, such as burst pipes, sewer line problems or slab leaks, require immediate professional help. You should also call a plumber if you hear strange noises in your pipes, such as banging or gurgling, which could indicate pressure issues or blockages.

While DIY fixes work for minor issues, major leaks need expert repair to prevent costly damage. When in doubt, don’t wait − call a plumber before a small leak turns into a big disaster.

Don’t Let Problems Escalate

Plumbing leaks can start small but lead to big problems if left unchecked. Knowing how to spot the early warning signs − like water stains, musty odours or high water bills − can help you catch leaks before they cause serious damage.

Simple tests, like checking your water meter, inspecting pipes for corrosion, and using food colouring in your toilet tank, can help you find hidden leaks.

While some plumbing issues have easy fixes, others − like slab leaks or underground pipe damage − require professional attention. If you notice persistent leaks, low water pressure, or unexplained moisture, don’t wait to call a plumber. Preventative maintenance, like regular pipe inspections and leak detection devices, can also help you avoid future problems.

By staying proactive, you can keep your home safe from costly water damage and enjoy a reliable plumbing system for years to come.

Please note: This information is provided for advice purposes only. Regulations differ from state to state, so please consult your local authorities or an industry professional before proceeding with any work. See our Terms & Conditions here.