Real homes. Clear answers.

Cracks, sticking doors and uneven floors are stressful, especially when you don't know what they mean. Here is how we helped two Melbourne homeowners find out what was really going on, and what to do next.

Structural investigations in Melbourne.

When the drawings tell the real story

Case one. Melbourne's western suburbs.

A full-height crack appeared at the front of a newer townhouse. It looked like a patch-and-paint job. It turned out to be something the owner needed to know about straight away.

At a glance

The home
Double-storey rendered townhouse, relatively new
Noticed
A large crack at the garage, uneven floors, cracks inside
Worried
Is it safe? Was it built properly? Who is responsible?
Outcome
The cause, an urgent safety warning, and a clear repair plan

What the owner noticed: a garage wall pulling away from the house.

Over about a year, the owner watched cracks spread through their relatively new townhouse and noticed the floors no longer felt level. The biggest worry was a crack running the full height of the front of the garage, where the brick wall seemed to be pulling away from the rest of the house.

They had three questions: what's causing this, was the house built properly, and is it safe?

Full-height crack between the garage wall and the house
The crack at the garage
Tape measure held across the crack at the garage
Measuring the gap on site

What we did: we looked further than the crack.

A crack shows you where a building has moved. It doesn't tell you why. So we looked at the whole house, and then at how it was designed.

  1. Inspected the whole home

    Inside and out, every room, not just the obvious crack. We also checked the yard, drainage and nearby trees.

  2. Measured how much it had moved

    A precise floor level survey across the house, plus a thermal camera to look for hidden moisture behind walls and ceilings.

  3. Checked the original paperwork

    We reviewed the engineering drawings and soil report the house was built from. This is where we found what a visual inspection alone would have missed.

What we found: more serious than it looked.

The cracked wall was holding up the floor above.

What looked like a cosmetic crack was in a wall supporting part of the upstairs floor. We advised the owner to keep out of that area until it was made safe, and explained exactly what needed to happen first.

The garage foundation wasn't designed for what was built on it.

The garage was built in solid brick, which is heavier and less forgiving of ground movement than the rest of the house. The original drawings showed the same lighter foundation under the garage as under the house. On this site's clay soil, that was a likely reason the garage had moved.

The ground and the garden played a part.

Clay soil, nearby trees and poor drainage at the back added to the movement.

A bonus finding: missing insulation.

Our thermal camera showed gaps in the ceiling insulation upstairs and down. Not a structural problem, but worth fixing for comfort and power bills.

The garage foundation: the plans against what was needed

Scroll sideways to see the whole diagram.

Garage foundation: what the plans showed compared with what the site needed The plans showed a shallower, lightly reinforced foundation under the garage, the same as the rest of the house. For solid brick walls on this clay site, a deeper, more heavily reinforced foundation was needed. Clay soil What the plans showed Not deep enough Shallower, lighter reinforcement Same as the rest of the house What this garage needed Deeper, stronger reinforcement To carry solid brick on clay soil
Simplified illustration, not to scale. The plans used the same foundation under the solid brick garage as under the lighter brick veneer house. For the soil on this site, the garage needed a deeper, stronger foundation.

How it helped: from worry to a clear plan.

They knew what was urgent
The safety issue was picked up straight away, with clear advice on making it safe first.
They avoided paying for the wrong repair
Patching the crack would have hidden the problem, and it would likely have come back.
They had the right repairs, in the right order
A clear list of what to fix, what to check first, and what to keep an eye on.
They had independent evidence
A plain-English report to support any discussion with the builder.

If we had only looked at the crack, we would have missed the cause.

The answer was in the drawings, not on the wall. That is why we go further than a visual inspection, and why our reports are reviewed by our Chartered Professional Engineer (CPEng). We don't sell repairs, so our only job is to find the real cause.

Small cracks, big movement

Case two. Melbourne's outer west.

A few small cracks and some sticking doors in a well-kept family home. Easy to patch and forget, except the house had been moving for years.

At a glance

The home
Double-storey rendered home, around 20 years old
Noticed
Cracks in a bedroom wall, doors sticking
Worried
Is it just cosmetic, or something bigger?
Outcome
The real cause, peace of mind, and a step-by-step plan

What the owners noticed: a few small cracks.

The owners had lived in their home since it was built, around 20 years earlier. Cracks had started to appear in a bedroom wall and in a few other rooms, and some doors had become hard to open and close.

The cracks were small, the kind most people would fill and paint over. But the owners wanted to be sure before spending money on repairs.

Crack in the render running down from the corner of a window
Cracking below a window
Crack running through the external render
A longer crack higher up the wall

What we did: we measured the floors, not just the cracks.

Small cracks can be harmless, or they can be the first visible sign of something bigger. You can't tell which by looking at them, so we measured.

  1. Inspected every room

    Inside and out, upstairs and down, plus the garden, the slope of the yard and the trees nearby.

  2. Measured the floors

    A precise floor level survey across the whole house showed how much, and in which direction, it had moved.

  3. Dug out the original paperwork

    We reviewed the soil report and slab drawings from when the house was built, around 20 years ago.

What we found: the floors told a much bigger story.

The house had moved far more than the cracks suggested.

The cracks were small, but the floor survey found a 68 mm difference in level across the house. That is well beyond what is considered acceptable, and it explained the sticking doors.

The movement pointed straight at the trees.

The floors had dropped most at the front of the house, closest to some large street trees. The cracking followed the same pattern. The soil report from when the house was built had even warned that trees could cause problems one day.

The soil does the rest.

Like much of Melbourne's west, the house sits on clay that swells and shrinks as it gets wet and dries out. Combined with the trees and garden beds against the walls, the foundation couldn't keep up.

Good news: no immediate danger.

The house was not unsafe, which meant the owners could take a measured, step-by-step approach instead of rushing into expensive work.

How the tree affected the house

Scroll sideways to see the whole diagram.

How a nearby tree affected the house A large street tree at the front of the house draws moisture from the clay soil. The clay under the front of the house dries and shrinks, so the front of the house drops more than the back, causing cracks and sticking doors. Back Front and street Tree's influence zone Roots draw moisture from the clay, so it dries and shrinks Back of the house Soil stays more stable Front of the house drops Uneven floors, sticking doors Cracks appear where the house bends
Simplified illustration, not to scale. Large trees draw moisture out of clay soil, and clay shrinks as it dries. The part of the house closest to the tree dropped the most, which is exactly what the floor survey showed.

How it helped: the right steps, in the right order.

They didn't waste money on patching
Filling the cracks now would only have hidden them while the house kept moving.
They knew what to deal with first
Simple changes around the house and garden to stop the cause, before any repairs.
They got the right advice on the trees
Including why removing a big tree without advice can cause new problems.
They had a plan to watch and review
How to keep track of the cracks over the coming months, and when bigger repairs would actually be needed.

Small cracks don't always mean a small problem.

Two homes, two very different stories behind the cracks. That is why we never guess from a photo. We inspect, measure and check the paperwork, then explain it in plain English. Every report is reviewed by our Chartered Professional Engineer (CPEng), and because we don't sell repairs, our advice is independent.

Noticed cracks, sticking doors or uneven floors? Don't guess. Find out what's really going on.

Every home is different, and cracks that look alike can have very different causes. Tell us what you're seeing and we'll let you know if a structural investigation report is the right next step.

Request an assessmentAsk us a question

Prefer to talk? Call 0460 431 515.

Details have been generalised to protect each owner's privacy. Published with the owners' permission.