Does My House Need Underpinning? A Symptom Checklist

Wagga Foundation Repairs’ checklist below answers it in one line: your house likely needs underpinning if two or more of stepped brick cracks over 5mm, sticking doors on one side, floors sloping toward a corner, gaps at window frames, or a failed stump or footing are showing up together, rather than in isolation. Work through the checklist to see where your home sits.

One symptom on its own rarely means much on Wagga’s reactive clay: hairline cracks, a single sticking door or a slightly springy floorboard are common in almost every home in the Riverina at some point. What matters is whether several of these signs are turning up together, and whether they’re getting worse rather than staying put. This checklist pulls together the warning signs already published across our service pages so you can run through them in five minutes and see roughly where you stand, before you spend a cent on repairs.

What are the warning signs my house might need underpinning?

If footings are genuinely on the move, the signs tend to cluster rather than appear one at a time. The pattern to look for:

• Stepped or diagonal cracks in brickwork wider than a few millimetres, especially ones that keep growing or reopen after patching
• Doors and windows that stick or won’t latch on one side of the house, when they used to close fine
• Floors sloping noticeably toward one corner or wall
• Gaps opening between brickwork and window frames, or between walls and the ceiling
• Cracks that visibly widen after a long dry spell or a very wet winter, the classic signature of Wagga’s drought-and-wet moisture cycle working on reactive clay

None of these individually confirms underpinning is needed. A cluster of three or more, especially if they’re worsening, is the point where a proper foundation inspection earns its keep rather than a guess from a photo.

Is it just a cosmetic crack, or something structural?

Crack width is the single most useful clue you can read yourself, and it’s worth checking before you worry about anything else on this list. Engineers commonly grade wall cracking by width, and while width alone never tells the whole story, it’s a sensible starting filter:

Two cracks of the same width can still mean different things: a 3mm crack that’s sat stable for a decade is not the same animal as a 3mm crack that measured 1mm at Christmas. Our full guide to cracks in walls and when to worry walks through crack patterns in more detail, including which shapes (stepped, diagonal from a window corner, horizontal) tend to matter most. If your inspection report starts using terms like settlement, subsidence or heave, our guide to subsidence, settlement and heave explained sets out what each one actually means.

Do sloping or bouncy floors always mean underpinning?

Not necessarily, and this is where a lot of homeowners jump to the wrong conclusion. Sloping floors are worth investigating when they visibly slope, bounce or dip in particular rooms, when furniture rocks or doors swing open by themselves, when gaps have opened under skirtings, or when cracks appear at cornices and door heads on the low side of the house.

But sloping floors on their own, with no cracking anywhere, often point to house re-levelling rather than underpinning: the floor has dropped, but the footing hasn’t necessarily failed in a way that needs strengthening. Re-levelling treats the level of the floor; underpinning treats the footing underneath it. It’s also worth ruling out floor bounce caused by undersized joists or bearer spans, which is a carpentry issue, not a foundation one, and lifting a house while the ground beneath it is still actively moving can waste money regardless of the technique used. This is exactly the kind of distinction a site inspection sorts out quickly.

Could the problem be stumps, rather than footings?

If your home is a post-war build sitting on timber stumps, a different checklist applies before underpinning even enters the conversation. Signs that point to stump failure rather than footing movement include:

• Soft, bouncy or springy floors, especially along high-traffic paths like hallways
• Floors dipping toward the middle of a room in a patchy rather than uniform pattern, because stumps sink individually
• Doors and windows binding in parts of the house that used to be fine
• Visible stumps under the floor that are leaning, mushrooming at the base, soft when probed, or showing termite damage
• A damp under-floor smell, which speeds up stump decay in flood-fringe blocks near the Murrumbidgee and the lagoon systems

Homes on strip footings or slabs get underpinning; homes on failing stumps get restumping and reblocking instead. Some older Riverina homes are a mix, an original stumped cottage with a slab extension, and an inspection is what works out which parts need which treatment.

The checklist: work through these five symptom groups

Run through this list room by room. Tick anything that applies, even loosely:

• Stepped or diagonal brick cracks wider than about 5mm, or cracks that have visibly grown
• Doors or windows sticking, binding or failing to latch on one side of the house
• Floors sloping noticeably toward a corner or wall (use a marble or level if you’re not sure)
• Gaps opening between brickwork and window or door frames, or between walls and the ceiling
• Visible stump or subfloor problems: leaning, rotted or termite-damaged stumps, or a damp under-floor smell

Zero or one tick, especially if the crack in question is under 5mm and stable, usually means monitor and re-check in six to twelve months. Two or more ticks, or anything getting worse over a season, is worth a proper look before you decide on a fix.

Which repair does each checklist result point to?

The table below matches common symptom combinations to the repair method and indicative price band most homeowners in that situation need, based on the figures already published for each of our services. A site inspection always confirms the actual scope before anything is quoted.

*Indicative ranges only, drawn from each service’s own published cost breakdown; every job is confirmed after a site inspection and a formal written quote from a licensed local contractor.

What should I do if my checklist raises red flags?

If you’ve ticked two or more boxes above, or one symptom is clearly worsening, the next sensible step is a foundation inspection, not a phone call straight to an underpinning contractor. An inspection maps the cracks, surveys floor levels, checks the subfloor or slab edges where accessible, and gives you a written recommendation, which is sometimes simply to monitor for another season rather than start structural work.

Before you book anything, it’s worth ruling out the cheap fixes first: check downpipes aren’t discharging beside the footings, make sure garden beds aren’t being watered hard against a wall, and note whether any large trees sit close to the affected side of the house. Moisture imbalance around footings is the most common driver of movement on Wagga’s reactive clay, and sometimes correcting drainage does more for a wall than any structural work would.

Photograph every crack with something for scale, note the date, and if you can safely see under the floor, note anything about stump condition. That record makes any inspection faster and more useful. When you’re ready, get a free quote and tell us your suburb, what you’ve ticked on this checklist, and how long it’s been happening; we’ll line up a licensed local specialist to give you a straight answer.

All structural work referred through this checklist is carried out by appropriately licensed local builders and specialists, with structural or geotechnical engineers involved where the situation calls for it, and licence details supplied with every quote.

Does My House Need Underpinning? FAQs

I’ve only got one small crack. Do I need underpinning?

Probably not yet. A single crack under 5mm that isn’t growing is common on reactive clay and usually falls into the monitor-and-recheck category. Underpinning becomes a real conversation when that crack is paired with other symptoms, such as a sticking door or sloping floor nearby, or when it’s clearly widening over consecutive seasons.

My checklist ticked boxes from both the crack list and the stump list. What does that mean?

It usually means part of your home needs one repair and another part needs a different one, which is common in older Riverina homes with a stumped original section and a later slab or brick extension. A foundation inspection assesses each part of the house separately rather than assuming one diagnosis covers the whole building.

Can I skip the inspection and just book underpinning directly?

You can ask for a quote directly, but most licensed contractors will still want to inspect first, because the underpinning method (mass concrete, screw piers or resin injection) and the number of underpins needed depend entirely on what’s actually happening under the house. Skipping that step risks paying for more, or the wrong kind of, work than your home needs.

Does the season affect how my checklist reads?

Yes. Cracks in Riverina homes genuinely open and close with soil moisture, often widest late in a dry summer and tightest after a wet winter. If you’re ticking boxes during a dry spell, it’s worth re-checking after the next decent rain before drawing firm conclusions, and mentioning the seasonal pattern if you do book an inspection.

What if my floors slope but I can’t see any cracks at all?

That’s actually a reasonably common and often lower-concern combination. Gradual, even settlement with no cracking can mean the floor needs re-levelling rather than the footing needing underpinning. It’s still worth an inspection to rule out early-stage stump or slab movement, particularly if the slope has appeared or worsened recently.

How urgent is it once I’ve ticked several boxes?

There’s rarely a need to treat this as an emergency. Reactive clay problems develop over seasons, not days, so booking an inspection within the next few weeks is normally plenty of time. The exceptions are sudden changes, a crack that visibly opens overnight, a stump that gives way, or new bowing brickwork, which warrant a call sooner rather than later.