Top Defects Pre-Sale Inspections Find That Derail Home Sales

Top 5 defects that pre-sale inspections find that cause home sales to fall through
Five defects that derail home sales — and what they cost when you find them late.

About the author: Michael Tuder is a Victorian Building Authority Registered Builder and the founder of Star Building Inspections. With 30+ years building and inspecting homes across Melbourne’s western suburbs, Michael personally carries out every inspection. AS4349.1-2007 and AS4349.3 compliant.

Sellers are usually optimistic about their home. After 30+ years of inspections across Melbourne’s western suburbs, I can tell you the things that scare buyers — and the same handful of defects come up again and again. Most are fixable, sometimes for a few hundred dollars. Found by your buyer’s inspector instead of yours, they cost you the deal or thousands off the price. Here are the defects that most often derail home sales, and what you can do about each before listing.

Quick answer: The defects most likely to kill a home sale are wet-area moisture and waterproofing failure, missing or short roof flashings, retaining wall failure, balcony waterproofing failure, structural cracking, termite activity, and unpermitted alterations. Each is a six-figure scare to a buyer reading an inspection report — but a four-figure fix when you find it first.

1. Wet-area moisture and waterproofing failure

This is the single most common deal-killer in Melbourne’s western suburbs. Buyers’ inspectors look hard at wet areas. Vendors rarely do.

What buyers’ inspectors find:

  • Drumminess in floor tiles — the substrate is wet
  • Mould or staining through grout lines
  • Dark patches on the ceiling below a bathroom (in double-storey homes) or in the sub-floor below
  • Skirting damage in rooms adjacent to the bathroom
  • Cracked or perished silicone at floor-wall junctions
  • Floor waste sitting proud of the tile, suggesting water pooling

[Image: bathroom floor with drumminess and stained grout]

Why it scares buyers: a full bathroom strip-and-rebuild is $15,000–$30,000 in 2026. The fear is that what is visible is the tip — water has already damaged framing and plasterboard inside the wall.

What you can do pre-sale:

  • Re-silicone every floor-wall junction (1-day job, under $200)
  • Replace cracked grout (cosmetic, $300–$500)
  • If the membrane is genuinely failing, get a quote — and either fix or disclose

A bathroom that looks dry and freshly silicone-sealed gets a different inspection result than one that does not.

2. Missing or short roof flashings

Roof flashings are the metal strips that direct water at every junction — chimney, vent pipes, valleys, wall abutments, skylights. When they are short, badly lapped, or missing, water enters the roof void and stays there.

What inspectors find:

  • Stains on roof void timber below flashings
  • Rotted battens or trusses near flashing failure points
  • Mould on sarking or insulation
  • Internal ceiling stains — the dead giveaway

[Image: roof flashing too short above wall abutment]

Why it scares buyers: ongoing roof leaks suggest structural damage, mould inside the home, and an expensive trade callout history that did not solve the problem.

What you can do pre-sale: a roofer can re-flash a chimney or rework valley flashings for $400–$1,500 depending on access. Cheap relative to losing the buyer.

3. Retaining wall failure

Common in the sloped pockets of Melbourne’s west — Manor Lakes, the older parts of Werribee, hillside Melton developments. Retaining walls fail when drainage is missing, the wall was under-engineered, or the materials have aged.

What inspectors find:

  • Wall leaning out of vertical
  • Cracking in masonry or concrete walls
  • Bulging in timber sleeper walls
  • Soil washout at the base or behind the wall
  • Rotted timber at the base

[Image: timber sleeper retaining wall leaning forward]

Why it scares buyers: failing retaining walls can affect the house footings if the wall supports a slope above them. Replacement of a 20m retaining wall is $20,000–$50,000+.

What you can do pre-sale: get an engineer to inspect if the wall has visible movement. A small intervention now (drainage, anchors, partial rebuild) is cheaper than the buyer demanding a full replacement off the price.

4. Balcony and deck waterproofing failure

Tiled balconies above living spaces are a chronic trouble area in 2000s and 2010s Melbourne homes. Original waterproofing under the tiles often fails by year 10 to 15.

What inspectors find:

  • Tile drumminess on the balcony floor
  • Efflorescence (white salt deposits) at balcony edges
  • Stains on the ceiling in the room directly below
  • Failed silicone at door thresholds and balustrade fixings
  • Rusting balustrade fixings — the membrane has let water through

[Image: balcony tile efflorescence at the edge]

Why it scares buyers: like wet areas, the visible defect implies hidden damage to framing and ceilings. Balcony rebuilds are $10,000–$25,000.

What you can do pre-sale: assess severity. Minor issues fix with sealant work. Major issues are a strip-and-redo job — get a quote, decide whether to fix or disclose with a price adjustment.

5. Structural cracking

Every older home in Melbourne’s clay-soil western suburbs has cracking. The question buyers’ inspectors ask is: cosmetic settlement, or active movement?

The categories matter:

Category Width Buyer reaction
0–1 <1mm Ignored
2 1–5mm Noted, monitored
3 5–15mm Engineer recommended
4 15–25mm Significant intervention required
5 >25mm Major or rebuild

What inspectors find:

  • Stepped cracks in brickwork, especially above and below windows
  • Diagonal cracks at corners of openings
  • Vertical cracks in render at construction joints
  • Floors out of level measured with a laser
  • Doors and windows binding — windows that no longer close are a major flag

[Image: stepped diagonal crack in brickwork above window head]

Why it scares buyers: structural movement implies expensive footings work — re-stumping, underpinning, or worse.

What you can do pre-sale: get an engineer to assess Category 2+ cracks. An engineer’s letter explaining “stable, historical, no remedial action required” stops the buyer’s panic before it starts. If active movement is confirmed, you have a decision to make about disclosure and price.

6. Termite activity and damage

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Melbourne’s western suburbs have moderate to high termite pressure. Subterranean termites do not announce themselves. Buyers’ inspectors are trained to find them and react strongly when they do.

What inspectors find:

  • Live mud tubing on stumps, piers, or interior surfaces
  • Damaged timber in skirtings, architraves, structural members
  • Frass (termite droppings) in roof voids
  • Conducive conditions — sub-floor moisture, garden beds against weep holes, timber-to-ground contact

[Image: live termite mud tubing on internal pier]

Why it scares buyers: termite damage to load-bearing members can run to tens of thousands. Insurers do not cover termite damage. The fear factor is high.

What you can do pre-sale: book a pest inspection. If there is no activity, you have a clean report to share. If there is, treat it before listing and provide the certificate. Disclosed and remediated termite history is far less damaging than an unannounced discovery by the buyer’s inspector.

7. Unpermitted alterations

Frequency that each defect type kills a sale
How often each defect type causes a deal to fall over.

Extensions, decks, garages, carports, and re-stumping done without permits show up in two places: the inspector’s report (mismatch with the original plans) and the buyer’s conveyancer’s council search.

What inspectors flag:

  • Extensions that do not appear on the title or council records
  • Decks built without engineering
  • Carports converted to garages
  • Bathrooms or kitchens added without compliance certificates
  • Re-stumping without a building permit

Why it scares buyers: unpermitted work is the buyer’s problem after settlement. Council can require removal or retrospective approval. The buyer either walks or demands a major price adjustment.

What you can do pre-sale: talk to your conveyancer. Retrospective building approvals are sometimes possible. Disclosure with a small price adjustment is usually a better outcome than a deal collapse.

How to use a pre-sale inspection report

Once you have the report, you have three real options:

  1. Fix the major defects before listing, especially the deal-killers above.
  2. Get an engineer’s letter for cracking and an updated certificate for termites.
  3. Disclose the report through your agent to serious buyers, with the work you have done documented.

For the bigger picture on whether a pre-sale inspection is worth it, see our post on whether you should get a pre-sale building inspection.

Frequently asked questions

If I find a defect, do I have to disclose it?
Disclosure obligations sit under the Section 32 (legal) and the contract of sale. The building inspection itself is your document. Whether and how you disclose is a question for your conveyancer or solicitor — see our post on vendor disclosure vs vendor inspection.

Will fixing defects always pay back?
Usually. A $1,500 silicone-and-grout refresh that prevents a $20,000 buyer-driven price reduction pays back many times over. The exception is large structural work close to settlement — sometimes disclosing with a price adjustment makes more financial sense than rushing a major job.

Can I get the same inspector who did my inspection to also fix the defects?
No. Building inspectors who do remediation work have a conflict of interest. We inspect, document, and recommend. Licensed trades do the work.

How quickly can defects be fixed before listing?
Cosmetic and small trade work — under two weeks. Major remediation (bathroom rebuild, structural work) — six weeks to several months. Plan inspections early so you have time.

Will the buyer’s inspector still find more after I have done the pre-sale fix?
Usually they will find a small handful of items in addition. That is normal — no two inspections produce identical lists. The point of the pre-sale is to remove the major issues that scare buyers, not to eliminate every cosmetic note.

Do you do pre-sale inspections in Werribee, Hoppers Crossing, and Point Cook?
Yes — across all of Melbourne’s western suburbs. Same-day photo-rich PDF reports.

Book a pre-sale inspection

Find the deal-killers before your buyer does. Star Building Inspections runs registered-builder pre-sale inspections across Melbourne’s western suburbs — Hoppers Crossing, Werribee, Point Cook, Tarneit, and beyond. Read more about our pre-sale building inspection service, or call Michael on 0412 014 216.

Related reading:
Should you get a pre-sale building inspection before listing?
Vendor disclosure vs vendor inspection: what’s the difference?


INFOGRAPHIC

Top 5 sale-derailing defects — and what they typically cost

Critical
Termite damage
Active or historical — $8-25k structural repair
Critical
Roof leak
Visible water staining — $3-12k roof + ceiling
Major
Slab crack > 5mm
Indicates movement — $5-30k underpinning
Major
Outdated electrical
Non-compliant switchboard — $2-8k rewire
Moderate
Plumbing leaks
Slow leak in walls — $1-5k pipe replacement

What customers say about Star

First time round Michael discovered a 'major defect' — water leaking from shower into next room. I had been told by the agent there were no problems. He saved me tens of thousands in repairs. When he gave me the all clear on the second property, I felt confident putting in an offer.
— Barb K.  ·  ★★★★★
Michael is a registered builder and this makes him qualified to put across a report that is in line with the REAL TRUE outcome needed of a building and pest inspection. His business is purely on word …
— Karthikeyan H. · ★★★★★
Michael had uncovered various major defects and I feel like I have dodged a bullet by doing this inspection. In the end I withdrew from purchasing the property.
— Nadhila · ★★★★★
That evening I had a good 30 minute conversation with him over the phone about what was found in the report, and he took the time to explain everything in terms I understood.
— Frances G. · ★★★★★
INFOGRAPHIC

How we grade defects

Critical
Safety / structural
Don't sign contracts
Major
Costly to remediate
$5-25k repair
Moderate
Maintenance item
Fix within 12 months
Minor
Cosmetic
DIY or schedule
Problem

You list, buyers inspect, their report finds 3 issues you didn't know about, and the deal falls over or gets re-negotiated 20k below your asking price.

Solution

Star does a pre-sale inspection BEFORE you list. You see the report first, fix what's cheap, disclose what isn't, and remove the buyer's "gotcha" leverage entirely.

INFOGRAPHIC

Why customers choose Star

157
Google reviews
Same day
Report by 6pm
🏗
20+ yrs
VBA-registered
📞
100%
Phone walkthrough

Across Melbourne's west

INFOGRAPHIC

Chain inspectors vs Star

FactorChain inspectorStar (independent)
Inspector continuityRotating staffMichael every time
VBA-registered builder
Report walkthroughyes — phone call
Same-day reportyes (by 6pm)
Cost$300-450$450-650

Why book Star Building Inspections?

Star Building Inspections is owned and operated by Michael Tuder — a VBA-registered builder with 20+ years inspecting homes across Melbourne's western corridor. Michael personally attends every inspection, writes every report, and calls every customer to walk them through the findings line by line. No contractors. No rotating staff. No outsourced sign-offs.

157
Google reviews
5.0
Stars
20+
Years experience
Same day
Report by 6pm

Book a pre-sale inspection

Find your home's issues before the buyer does. Defends asking price, removes the buyer's 'gotcha' leverage, speeds the settlement.

Michael Tuder, VBA-registered building inspector, Melbourne western suburbs
Written by
Michael Tuder

Michael Tuder is the owner of Star Building Inspections and a VBA-registered builder with 20+ years of experience inspecting homes across Melbourne's western corridor. He grew up here, lives here, and personally attends every inspection — no contractors, no rotating staff. Star has earned 157 five-star Google reviews, and Michael calls every customer to walk through the report line by line.

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