Parts of Campbelltown and the wider Macarthur area sit on reactive clay soils. Clay swells when it’s wet and shrinks as it dries, and a concrete pool shell sitting in it can feel that movement. It’s why cracks are one of the most common reasons Campbelltown pool owners call us.
We have 17 years on the tools, and we treat a crack as a question to answer, not a patch to cover. For the wider area, see our South West Sydney page.
Why clay soil cracks a pool
Reactive clay doesn’t always move evenly. One section of the ground can swell or settle more than the next, and that puts stress on a rigid shell. The result is often a crack, sometimes a fine surface line and sometimes something deeper. Other things can contribute too, including groundwater pressure and the age of the pool, so not every crack is the clay’s fault.
- Seasonal wet and dry cycles that change how much the ground moves
- Leaking water softening the ground around the shell
- Groundwater pressure pushing against an empty pool
- Age and previous repairs that have let go
Sorting a surface crack from a structural one
Not every line means trouble. This is the quick way we think about it, and the full explanation is in our pool crack repair guide.
| What you see | What it may be | What happens next |
|---|---|---|
| Fine lines or crazing in the surface | Often a surface-level issue | Assessed and repaired as part of the resurface |
| A crack you can feel with a fingernail | Could involve the shell | Opened up, repaired and sealed properly |
| A crack that is wide, stepped or growing | May be structural | Needs an engineer to look before any repair |
| A crack plus ongoing water loss | The crack may be leaking | Needs finding and fixing at the cause |
Straight answer: if a crack looks structural, we’ll say so and suggest an engineer before we quote the surface. We won’t paint over something that needs real attention.
How we repair a crack properly
- Mark and map the cracks once the pool is empty and the surface is stripped
- Open each crack up so the repair gets right into it, rather than filling the top
- Repair and reinforce the area, then seal it
- Check the area again before the finish goes on
That’s very different from filling a crack and painting over it, which usually shows again within a season. If you’re comparing options, our guide to pool painting explains when paint is sensible and when it isn’t.
Water loss, leaks and clay
A cracked pool in clay can lose water, and water leaking into clay can make the ground move more. If your level keeps dropping, don’t ignore it. Our guide on why a pool loses water shows you how to tell evaporation from a leak.
Draining with care
Clay and high groundwater make draining a pool riskier, especially after heavy rain. We check ground conditions and the hydrostatic valve before we empty anything, which is explained in our guide to pool hydrostatic valves. Please don’t drain a pool yourself after wet weather.
Older pools and newer estates
Campbelltown and Macarthur have older established pools alongside newer estates, and clay behaves differently depending on how a site was prepared and how the pool was built. An older pool may have had movement and previous repairs, while a newer one may only be showing its first signs. Either way, we inspect the shell as it is, not as we’d assume it to be, and we tell you what we find in plain terms.
Timing it for summer
Pool season opens in November, and people book for different dates: November, Christmas or later in summer. Repairs can add to the timeline, so an early inspection helps us plan. Everything about the main process is on our pool resurfacing page.
