Pre-Purchase Plumbing Inspections: What to Ask For and Why It Matters

A pre-purchase plumbing inspection is a check of a property’s plumbing, drainage and gas systems by a licensed plumber before you buy, and it covers the faults a standard building inspection cannot. The most expensive plumbing problems in a home are the ones you can’t see: a cracked or root-filled sewer under the slab, a hot water system on its last legs, or illegal work hidden behind a wall. Around The Clock Plumbing Pty Ltd, Oakleigh South, carries out independent pre-purchase plumbing inspections across Melbourne’s south-east and Bayside, and this checklist explains exactly what to ask for and why it matters before you sign.

What does a standard building inspection miss?

Standard pre-purchase building inspections in Australia are carried out to Australian Standard AS 4349.1, which covers the visible, accessible parts of a building’s structure. It is a worthwhile report, but it has two important limits when it comes to plumbing. First, a building inspector is not a licensed plumber, so any plumbing checks are basic and visual. Second, and most importantly, AS 4349.1 does not include a camera inspection of the underground drainage. That means you can buy a home with no idea the sewer line is partially collapsed, sagging, or full of tree roots until it backs up after you move in. The only way to actually see the condition of the buried pipework is a separate CCTV drain inspection by a licensed plumber.

Your pre-purchase plumbing inspection checklist: what to ask for

When you book a pre-purchase plumbing inspection, ask that it includes the following — and that you receive a written report you can actually act on:

A CCTV camera inspection of the sewer and stormwater drains. A camera that handles everything from 40mm to 305mm pipe is fed through the lines to check for root intrusion, cracks, collapses, displaced joints and incorrect falls. Root intrusion is the most common hidden fault in older homes — we explain why in our guide to blocked drains caused by tree roots.

A pressure or leak test of the water service. This reveals concealed leaks in walls or under the slab before they become your problem. The same acoustic and pressure techniques used for water leak detection in older homes apply here. Read more in our blog

The age and condition of the hot water system. Its make, age and likely remaining life, a unit near the end of its life is a near-term cost you should factor into your offer.

Gutters, downpipes and surface drainage. Whether stormwater is genuinely carried away from the building. Poor surface drainage is a common cause of damp, mould and structural movement.

Gas appliances and the meter. That gas work is safe and compliant, with no obvious illegal or unpermitted installations, a check that must be done by a licensed gas fitter. We carry the latest gas leak detection equipment to identify the hazadous gas leaks in your popety.

Signs of illegal or unlicensed plumbing work. DIY or unpermitted work that may need to be redone to meet Australian Standards, at your cost, once you own the property.

A clear written condition report. Setting out the defects, with photos or video, and what they actually mean, so you can make an informed decision rather than take someone’s word for it.

Why does a pre-purchase plumbing inspection matter?

A home is one of the largest purchases most people ever make, and plumbing defects are both costly and easy to hide. A collapsed or root-infested sewer can cost far more to repair than the inspection itself, and illegal work can leave you liable to bring it up to standard. A pre-purchase plumbing report does one of two valuable things: it gives you peace of mind, or it gives you documented, photographed evidence to renegotiate the price ,or to walk away.

Because the inspection is diagnostic-led we arrive, find the actual condition of the pipes rather than guessing from what is visible, and document it , any defect can then be fixed properly, whether that is a pipe relining versus replacement decision or a targeted repair. For older homes in Melbourne’s established suburbs, particularly those built before the 1980s with mature trees nearby, a drain camera inspection is especially worth it.

Pre-purchase inspection vs an ongoing plumbing health check

A pre-purchase inspection is a one-off check before you buy. Once you own the home, a regular plumbing health check every couple of years stops small problems becoming plumbing emergencies. We cover that in our guide to plumbing health checks every 2–3 years. The two work together: one protects the purchase, the other protects the investment.

Frequently asked questions

Isn’t a standard building inspection enough?

Not for plumbing. A building inspection to AS 4349.1 covers visible structure and is done by a building inspector, not a licensed plumber, and it does not include a camera inspection of underground drains. A separate pre-purchase plumbing inspection is the only way to assess the buried pipework, hot water system and gas by an independent plumbing inspector.

What should a pre-purchase plumbing inspection include?

A CCTV inspection of the sewer and stormwater drains, a pressure or leak test of the water service, the age and condition of the hot water system, gutters and surface drainage, gas appliances, any signs of illegal work, and a written condition report with photos or video.

Can I use the report to negotiate the price?

Yes. Documented, photographed defects are strong evidence for renegotiating the purchase price, asking the vendor to repair before settlement, or deciding not to proceed. That is often where a pre-purchase inspection pays for itself many times over.

Should I get a drain camera inspection on an older home?

Especially on an older home. Properties built before the 1980s, and any home with mature trees nearby, are far more likely to have root intrusion, cracked clay pipes or sections laid at the wrong fall, none of which are visible without a camera.

Do you provide a written report I can rely on?

Yes. We provide an independent, forensic-grade written report with photos and camera footage, suitable for price negotiation, insurance, or a body corporate, and detailed enough to stand up if the matter is ever disputed. Book now.

Written/reviewed by Christopher Unwin — founder, Around The Clock Plumbing Pty Ltd, Oakleigh South. BPC Licence #50694, Type A gas, 22 years experience. National Council member, Master Plumbers Association.

Updated May 2026

Related reading: stormwater drainage problems in Melbourne