Guide

Restumping vs Underpinning: What's the Difference?

Wagga Foundation Repairs treats restumping and underpinning as two different repairs for two different problems: restumping replaces failed timber or concrete stumps under a floor, while underpinning strengthens or extends the footings under a slab or strip-footed home. Which one your house needs comes down to how it’s built, not how bad the cracks look.

The confusion is understandable. Both repairs get lumped together as “foundation work”, both involve licensed contractors jacking or excavating around a house, and both show up in the same search results when someone types a symptom into Google at 11pm. This guide pulls the two apart properly: what each one actually does, what it costs in the Riverina, how long it takes, and a short checklist to work out which conversation you’re actually having.

What’s the real difference between restumping and underpinning?

The difference starts with what’s holding your house up. A stumped home carries its weight through bearers and joists onto rows of individual stumps, usually timber in older Riverina housing stock, sometimes steel or concrete in later builds. When a stump rots, leans or sinks, restumping replaces it. A slab or strip-footing home carries its weight through a continuous concrete footing or slab edge. When that footing settles or loses support in Wagga’s reactive clay, underpinning extends or strengthens it so it bears on more stable ground.

In short:

  • Restumping is for homes on stumps, where individual supports have failed one by one.
  • Underpinning is for homes on slabs or strip footings, where the footing itself has moved.

If you’re not sure which category your house falls into, that’s normal. Plenty of Wagga homes are a mix, an original stumped cottage with a slab-on-ground extension out the back, for instance, and the only reliable way to know which repair applies where is a proper foundation inspection.

Does my house need restumping or underpinning?

Start with construction type, then match it to the symptoms you’re seeing.

Restumping & reblockingUnderpinning
Suits this constructionTimber-floor homes on timber, steel or concrete stumpsHomes on slabs or strip footings
What’s actually failingIndividual stumps: rotted, termite-damaged, leaning, or simply undersized for the ground movementThe footing itself: settling, cracking, or losing support as reactive clay shrinks and swells beneath it
Typical symptomsBouncy or spongy floors, floors dipping in patches, doors binding, a damp under-floor smell, visible leaning or mushrooming stumpsStepped or diagonal brick cracks, doors sticking on one side of the house, floors sloping toward a corner or wall
Common methodOld stumps removed and replaced with galvanised steel or precast concrete stumps, floor re-levelled as part of the same jobMass concrete underpinning, screw piers, or resin injection, chosen by an engineer based on depth to stable ground and access
Where it typically shows upOlder stumped suburbs and towns: Kooringal, Lake Albert, Junee and the smaller Riverina townsStrip-footed brick homes in Turvey Park and Central Wagga, and newer slab homes on cut-and-fill blocks in Estella and Boorooma

Reblocking is simply the term used in Victoria for the same restumping trade; in NSW you’ll mostly hear “restumping”, though some contractors use both words interchangeably.

How do restumping and underpinning costs compare?

Both repairs are priced by unit, restumping per stump, underpinning per underpin (pier or pit), so the total depends heavily on how many your house needs. Reusing the ranges already published on our restumping and underpinning service pages and our full underpinning cost guide:

RepairSmallest typical jobLargest typical jobPriced by
RestumpingPartial restump, 5 to 15 stumps: $3,000 to $10,000Full restump with bearer and joist replacement: $25,000 to $45,000+Per stump
UnderpinningSingle dropped corner, 2 to 4 underpins: $8,000 to $20,000Full perimeter, 14+ underpins: $50,000 to $80,000+Per underpin, indicatively $1,000 to $4,500 each

A few things drive both totals in similar ways: how many units (stumps or underpins) the job needs, how deep the work has to go before it reaches stable ground, access under or around the house, and whether rotted timber or unexpected soil conditions turn up once the work starts. Every one of these figures is an indicative guide only; the real number always comes from a site inspection and a formal written quote.

How do the two repairs actually compare on process and timeframe?

The mechanics look different because the problem being solved is different.

RestumpingUnderpinning
Where the work happensUnder the floor, in the sub-floor spaceAround the outside of the footing or beneath a slab edge
Does it usually include re-levelling?Almost always, because the house is already on jacks while stumps are replacedOnly where specified; underpinning stabilises the footing first, and re-levelling is often a separate step
Typical timeframeDays for a partial job; one to two weeks for a full restumpDays for a small job or resin injection; a few days to several weeks for larger excavated or piered work
Engineering involvementUsually a licensed contractor working to standard stump specificationsStructural or geotechnical engineer input is standard, especially for mass concrete or screw pier design
Living in the houseAlmost always, yes; work happens under the floorUsually, yes; most households stay put during the work

What if my house has both stumps and footings?

Plenty of Riverina homes aren’t a clean fit for either category. A common pattern locally is an original stumped cottage with a later slab-on-ground extension, or a stumped home where a previous owner poured a concrete strip footing under one section, the exact mix that turns up street by street in a semi-rural suburb like Forest Hill. In those cases, the inspection doesn’t pick one repair for the whole house; it works out which part needs which treatment, and it’s entirely normal for a single project to include both a restump on the original section and underpinning or crack repair on the extension. Our guide to why foundations move in Wagga explains why reactive clay affects these different construction types differently, which is useful background before that inspection.

A quick decision checklist

Work through these questions before you ring anyone:

  1. What is your home actually built on? Timber floors over an open sub-floor space usually mean stumps. Solid floors at ground level usually mean a slab or strip footing.
  2. Are the floors bouncy, or are the walls cracking? Springy, uneven floors point toward stumps. Stepped brick cracks and sticking doors point toward footings.
  3. Is the movement patchy or does it follow a wall? Stumps fail individually, so floor dips tend to be patchy. Footing movement more often follows a whole wall or corner.
  4. Can you see the sub-floor? If there’s crawl-space access, a look underneath (or better, a proper inspection) often settles the question in minutes.
  5. Is it a newer slab home? Newer slab homes, especially on cut-and-fill blocks in areas like Estella, are never a restumping job; if they’re moving, it’s underpinning territory, often assessed for resin injection first.

If you’ve worked through that list and you’re still not sure, that’s exactly what an inspection is for rather than a guess.

A worked comparison (indicative composite, not a real job)

To show how differently these two repairs can land in cost even on similar-sized homes, here’s an indicative composite scenario, not a real project or quote. Picture two hypothetical three-bedroom Wagga homes of similar size, each showing moderate symptoms in one section of the house. House A is a 1950s home on timber stumps with a bouncy, dipping hallway; a partial restump of the affected run of stumps sits in the $3,000 to $10,000 band. House B is a brick-veneer home of similar age on a strip footing with a stepped crack and one sticking door on the same corner; underpinning that corner (2 to 4 underpins) sits in the $8,000 to $20,000 band. Same era, similar symptoms in spirit, but a meaningfully different price, because one repair replaces failed point supports and the other extends a continuous footing down to stable ground. Neither figure is a quote for any actual home; both come only from the ranges already published in our service and cost guides.

Restumping vs Underpinning FAQs

Is restumping always cheaper than underpinning?

Not always, but often, because a partial restump can be scoped to just the failed stumps while underpinning typically needs at least a few underpins to properly support a section of footing. Compare like with like: a small partial restump (5 to 15 stumps, $3,000 to $10,000) is usually cheaper than underpinning a full elevation, but a full restump with bearer and joist replacement ($25,000 to $45,000+) can cost more than underpinning a single corner.

Can restumping fix cracked walls?

Sometimes, if the cracking was caused by the stumps sinking or leaning and the walls sit on a timber frame rather than full-height brickwork. But cracking in brick veneer or double-brick walls above a stump line, or any cracking in a slab or strip-footed home, is a footing issue that restumping won’t reach; that’s underpinning territory, followed by separate crack repair once the structure is stable.

My house is on stumps but has brick veneer walls. Which repair applies?

Both can be relevant to different parts of the same house. The stumps and floor frame are restumping’s job; genuine cracking in the brick veneer skin itself may need underpinning or crack repair depending on the cause. This is a common configuration in older Wagga suburbs, and it’s a good example of why an inspection looks at the whole picture rather than assuming one label fits the house.

Does either repair stop foundation movement from ever happening again?

Both address the specific problem found at the time (failed stumps, or an undersupported footing), but Wagga’s reactive clay keeps responding to moisture year-round, so ongoing care around drainage, downpipes and garden watering matters after either repair. Reputable contractors won’t promise either fix is a permanent guarantee against all future movement.

How do I get a straight answer for my own house?

Start with a foundation inspection rather than guessing from symptoms alone. An inspector confirms construction type, checks the sub-floor or footing directly, and recommends restumping, underpinning, both, or neither, with reasoning you can take to any licensed contractor for a second opinion. Get a free quote and we’ll arrange that inspection with a licensed local specialist.

Are both repairs covered by home insurance?

Rarely, in either case. Most home insurance policies exclude gradual movement from reactive soils, which is the common cause behind both stump failure and footing settlement in Wagga. Check your own policy before assuming either way, and where a contract crosses the relevant threshold, ask about home building compensation cover as part of the formal quote.

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