Gemark Consultancy

The $20,000 Plumbing Problem No One Checks

Here’s the uncomfortable truth:

Most buyers will spend hours looking at
• kitchens
• bathrooms
• paint
• finishes

But almost no one checks what’s happening underground.

And that’s where the expensive problems live.

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What we keep seeing

Across multiple properties, the plumbing system is:

• Still working
• Not visibly failing
• Passing basic inspection

But underneath?

• Old clay or earthenware pipes still in service
• New fixtures connected to outdated drainage
• Mixed pipe materials joined underground
• Stormwater discharging into soil instead of proper connection

All functioning…

Until they don’t.



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Why this matters

Because when these systems fail, it’s not a small fix.

It usually means:

• Excavation through driveways or slabs
• Full drainage replacement or relining
• Stormwater redesign
• Unexpected costs that blow past your buffer

And none of that shows up in a standard walkthrough.

⸻

The blind spot

Most inspections are visual.

They don’t assess:

• Subsurface drainage condition
• Stormwater capacity
• Groundwater behaviour



So buyers assume:

“If it’s working, it’s fine.”

That assumption is where people get caught.

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The takeaway

A property can be:

✔ Structurally sound
✔ Clean and well presented
✔ Fully functional

…and still carry hidden plumbing risk underground.

⸻

GemArk Consultancy
We don’t just check if it works.
We assess how long it’s likely to keep working.

Most buyers think building & pest covers plumbing.

It doesn’t. And it’s not supposed to.

Building & pest inspectors assess:

✔ Structure
✔ Framing
✔ Visible moisture
✔ Termites
✔ Roofing

They are not licensed to assess hydraulic performance under the Plumbing Code of Australia or AS/NZS 3500.

That means they don’t assess:

• Drainage capacity under load
• Stormwater design & balcony overflows
• Subsoil & groundwater management
• Backflow device compliance
• Heated water temperature control risks

A sewer line can be “not blocked”
… and still be sagging.

A balcony can “look fine”
… and have no compliant overflow.

A stormwater system can “drain”
… and still discharge into soil illegally.

These systems usually fail after settlement.
That’s when excavation starts.

That’s why Gemark exists.

We don’t replace building & pest.
We fill the plumbing gap.

If you’re buying in SEQ or Northern NSW,
ask yourself:

Have I had the plumbing assessed — or just looked at?

— Gemark Consultancy

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