A gap between wall and floor skirting is one of those things you notice one day and cannot stop thinking about. In a Wagga Wagga home, the honest answer is that it can be two very different things: seasonal timber shrinkage that closes back up with the rains, or a sign that part of the house has moved and the junction between wall and floor is no longer where it used to be. This guide helps you tell the difference, gives you a concrete monitoring protocol, and explains when a foundation inspection is the right next step.
Cosmetic gaps versus structural gaps
A cosmetic gap is one that exists because of how the materials respond to the climate. Timber skirting boards and hardwood or particle-board floors all expand and contract with changes in humidity. In Wagga’s dry summers, floors can shrink enough to open a small gap at the skirting. This type of gap tends to be consistent along the full length of a wall, uniform in size and close back up or reduce during the wetter months.
A structural gap is different. It opens because part of the house has moved. The floor has dropped or the wall has lifted, or both are moving in different directions. This type of gap tends to be:
- Concentrated in one part of the house rather than uniform around all walls
- Wider in some spots than others along the same wall, suggesting the floor is sloping
- Part of a cluster of other symptoms: sticking doors, cracks, sloping floors in the same area
- Getting progressively wider over weeks or months rather than cycling with the seasons
The most important question is whether the gap is isolated and stable or whether it is part of a wider pattern of movement. Isolated, stable gaps are low concern. A gap that appeared suddenly in the same week your doors started sticking and a crack opened above a window is a different matter. See our guide on why foundations move in Wagga to understand the clay-soil context behind these symptoms.
What size gap starts to matter
There is no hard number that separates cosmetic from structural, but some useful rules of thumb for a Wagga home:
| Gap size | What it typically means | Action |
|---|---|---|
| 0-3 mm, consistent around walls | Seasonal timber shrinkage | Monitor; likely cosmetic |
| 3-8 mm, localised to one area | Could be cosmetic or early movement | Monitor closely with dated measurements |
| 8-15 mm, particularly in one spot or widening | Significant movement likely | Book a foundation inspection |
| Over 15 mm, or gap you can clearly see through | Active or historical structural movement | Inspect promptly |
These are general guides only. A 10 mm gap that has been stable and unchanged for fifteen years in an older home is different from a 5 mm gap that appeared three months ago and has been growing.
Seasonal shrinkage in Wagga’s dry summers
Wagga’s climate creates more thermal and moisture cycling than coastal cities. Summer temperatures regularly exceed 35 degrees and humidity can drop below 20 percent during dry spells. This causes timber components to shrink more noticeably than in more temperate parts of NSW.
In a timber-floor home in Turvey Park or North Wagga, it is normal to see small gaps appear at skirting boards by February and largely close by July. This is the floor joists, floorboards and skirting all responding to the same dry conditions.
The tell is what happens when the seasons change. A gap that closes in winter and reopens in summer is the climate at work. A gap that opened in March and is still there in August, possibly larger, is not just the climate.
A related symptom worth checking is whether the floor itself is sloping toward the wall with the gap. A gap that is wider at one end of a skirting run than the other, combined with a floor that slopes toward that end, is a stronger signal that the floor has actually dropped. See uneven and sloping floors for how to measure a slope yourself.
When gaps appear alongside cracks and sticking doors
A single skirting gap on its own is low priority. The same gap appearing in the same month as sticking doors and diagonal cracks at window corners is a different situation.
Foundation movement leaves a trail of symptoms across a house. Think of them as a cluster rather than individual problems. If you are finding gaps at the skirting in the back bedroom, a sticking door in the hallway next to it, and a crack running from the corner of a window in the same room, these are likely all connected to the same underlying movement.
The guide to cracks in walls and when to worry covers crack classification in more detail. The sticking doors guide covers that symptom. If you have two or three of these symptoms appearing around the same time in the same part of your house, book an inspection rather than waiting.
Conversely, if the skirting gap is the only thing and everything else in the house looks fine, monitor it rather than panicking.
Simple monitoring: pencil, ruler, calendar
Before calling anyone, set up a quick monitoring system. It takes five minutes and gives you useful information to share with any professional later.
Step 1: Choose the worst gap you can find. Mark the skirting board and the floor on either side of the gap with a pencil line at the widest point.
Step 2: Measure the gap at that point with a ruler and write the measurement on the wall next to the mark. Include today’s date.
Step 3: Photograph it clearly with your phone, making sure the ruler is visible in the frame. Add the photo to a folder named by date.
Step 4: Repeat the measurement monthly for three months. Note whether the gap is growing, shrinking or stable.
What you are looking for: a gap that grows by more than 1-2 mm per month is active movement and warrants professional attention. A gap that stays constant or closes slightly in winter and opens in summer is almost certainly seasonal. A house relevelling service may be needed if the floor has genuinely dropped, but the monitoring data helps determine urgency.
When to book an inspection
Stop monitoring and book a foundation inspection if:
- The gap has grown by more than 3-5 mm across two measurements
- The gap is wider at one end of the wall than the other, indicating a sloping floor
- You can see light through the gap, suggesting it is 10 mm or more
- Other symptoms have appeared in the same area: cracks, sticking doors, bouncy floors
- You are about to sell the property or want a professional condition report
- You are buying a home that has visible skirting gaps and want them assessed
A professional assessment can confirm whether the movement is historical and stable or active and likely to continue. That determination drives the repair decision, so it is worth getting right before committing to any work.
FAQs
Is it normal to have gaps under skirting boards?
Small, consistent gaps of 1-3 mm are common in older homes and often reflect seasonal timber movement rather than foundation problems. Larger gaps, gaps that are growing, or gaps concentrated in one area of the house are worth monitoring or having assessed. On their own, gaps under skirting boards are a low-level symptom; the concern is what they appear alongside.
Can I just fill the gap with silicone?
Filling the gap with silicone or caulk is a cosmetic solution that is fine if the gap is stable and you are confident it is seasonal. If the gap is caused by ongoing foundation movement, the silicone will crack within months as the movement continues. Apply cosmetic filler only after ruling out active movement, not before.
Why is the gap wider at one end of the skirting than the other?
An uneven gap, wider at one end of a wall than the other, usually means the floor is sloping in that direction. This is a more significant finding than a uniform gap because it indicates the floor structure has moved unevenly, which points toward a footing or stump problem rather than simple timber shrinkage. Measure the slope as described in our uneven floors guide and consider an inspection.
How quickly do foundation gaps appear?
Active foundation movement can produce visible skirting gaps within weeks in severe cases, particularly after heavy rain saturating reactive clay or after a prolonged drought causes rapid soil shrinkage. More typically, gaps that result from gradual settlement develop over months or years and are noticed only when they reach a size that catches the eye.
What does it cost to fix a skirting gap from foundation movement?
The gap itself is a cosmetic repair costing very little. The underlying foundation problem that caused it is what costs money, and the range is wide depending on the cause. A stump that has shifted slightly might be a relatively minor re-levelling job. A footing that has dropped significantly on reactive clay may require underpinning. A proper inspection is the starting point before any cost can be estimated. Contact us for a free quote.