July 15, 2026

Signs of Foundation Problems in a Melbourne Home

Quick answer. The common signs of foundation or footing problems in a Melbourne home are cracks in walls, especially stepped or diagonal cracks wider than about 5 mm, doors and windows that stick or no longer close, floors that slope or feel uneven, and gaps opening between walls, cornices, and skirting boards. Most are caused by footing movement on Melbourne's reactive clay soils, which swell and shrink with moisture. Signs that are widening or appearing together should be assessed by a structural engineer.

Foundation problems rarely announce themselves. They show up as small, everyday annoyances, a door that has started to catch, a new crack above a window, a floor that feels slightly off. Individually these can be harmless, but together, or when they are growing, they can point to the footings moving underneath the house. This guide sets out the signs a structural engineer looks for, what causes them in Melbourne, and when they are worth acting on.

What Are the Signs of Foundation Problems?

The signs of foundation problems are the ways a house shows that its footings are moving, from cracking to sticking doors to uneven floors. No single sign is conclusive, but a pattern of them, or any that are clearly widening, is what warrants attention. The table below sets out the common signs and what each can indicate.

Sign	What it can indicate
Stepped or diagonal cracks in brick or plaster	Differential footing movement, often from reactive soil
Cracks wider than about 5 mm, or widening over time	Movement worth a structural engineer's assessment
Doors and windows that stick or will not close	The frame is being distorted by movement
Floors that slope, dip, or feel uneven	Footings settling or heaving unevenly
Gaps opening at cornices, skirtings, or wall junctions	Parts of the structure moving apart
External cracking or a leaning wall	More significant movement, assess promptly

Direction and movement matter as much as the crack itself. A hairline crack that has not changed in years is very different from a stepped crack that has widened since summer. When several signs appear together, they tell a structural engineer that the footings, not just the finishes, are on the move.

What Causes Foundation Movement in Melbourne?

The most common cause of foundation movement in Melbourne is reactive clay soil, which swells when wet and shrinks when dry, lifting and dropping the footings with the seasons. Because much of Melbourne sits on reactive clay, this is the background cause behind most footing movement in the city. Other causes add to it, and often it is a combination that tips a house into visible damage.

Reactive clay soil swelling and shrinking with seasonal moisture change.
Large trees drawing moisture from the soil under the footings.
Plumbing leaks or poor drainage wetting the ground unevenly.
Poor site drainage allowing water to pond against the building.
Inadequate or shallow original footings for the site conditions.

Are Foundation Problems Serious?

Foundation problems range from cosmetic to serious, and the difference is the cause and the rate of movement, not just the size of a crack. Fine, stable cracking is common and often cosmetic. Cracking that is wide, stepped, growing, or accompanied by sticking doors and sloping floors can indicate active footing movement that will continue if the cause is not addressed. The reliable way to tell the two apart is a structural engineer inspection, because the engineer identifies the cause rather than just the symptom.

When Should You Call a Structural Engineer?

Call a structural engineer when the signs are widening, when several appear together, or when cracking is wider than about 5 mm, runs in a stepped or diagonal pattern, or is accompanied by doors and windows that have started to jam. A structural engineer inspects the building and the site, identifies whether the footings are moving and why, and sets out whether the situation should be monitored, repaired, or investigated further, in a written report.

How Are Foundation Problems Fixed?

Foundation problems are fixed by first identifying the cause, then addressing it, which is why the engineering assessment comes before any repair. Sometimes the fix is managing moisture around the house, improving drainage, or removing the influence of a tree, so the soil movement settles. Where the footings themselves need attention, a structural engineer designs the appropriate remediation, which can include strengthening or underpinning where required. The repair follows the diagnosis, because treating the symptom without the cause rarely lasts.

Frequently asked questions

What are the first signs of foundation problems?

The first signs are usually small, a door or window that has started to stick, a new crack above an opening, or a floor that feels slightly uneven. On their own these can be minor, but when they appear together or keep worsening they can indicate footing movement. Cracks that are stepped, diagonal, or wider than about 5 mm are the ones that most warrant a structural engineer's assessment.

What causes foundation problems in Melbourne?

The main cause in Melbourne is reactive clay soil, which swells when wet and shrinks when dry and moves the footings with the seasons. Other contributors include large trees drawing moisture from under the footings, plumbing leaks, poor site drainage, and inadequate original footings. Often it is a combination of these that leads to visible damage.

Are foundation cracks serious?

It depends on the cause and whether they are moving. Fine, stable cracks are common and often cosmetic, while wide, stepped, or growing cracks, especially alongside sticking doors and sloping floors, can indicate active footing movement. A structural engineer inspection is the reliable way to tell whether cracking is cosmetic or structural.

How do I know if my floor is sloping because of the foundation?

A sloping or uneven floor can indicate the footings are settling or heaving unevenly, but it can also have other causes such as timber subfloor issues. A structural engineer assesses the floor in the context of the whole building and the site to determine whether footing movement is the cause and what to do about it.

Can foundation problems be fixed?

Yes. Foundation problems are fixed by identifying the cause first, then addressing it, which may mean managing moisture and drainage around the house or, where the footings need attention, remediation designed by a structural engineer, including strengthening or underpinning where required. The diagnosis comes before the repair so the fix lasts.

General guidance only. This article is general education, not certified structural engineering advice. Every building, soil profile, and defect is different. For advice specific to your property, have a chartered structural engineer inspect it. Principal Built Engineering can assess your home and provide a structural engineer report.

Related PBE reading. See when to worry about cracks in walls for the crack detail, and structural engineer inspections for the inspection and report service.

Worried about movement in your home?

Principal Built Engineering assesses footing movement and cracking across Melbourne and Victoria and provides a structural engineer report in approximately two weeks.

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Last reviewed: July 2026 by Principal Built Engineering, structural engineers, Melbourne.

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