At a Glance
Perth's sandy soils provide generally stable ground for stumps and foundations, but structural repairs are still common in the city's older suburbs. Structural repair work in Perth typically costs $2,850–$23,750 per job, covering restumping, bearer and joist replacement, subfloor repairs, and load-bearing wall modifications.
What's Included in the Price
A structural repair quote covers assessment of the damage, removal and replacement of affected stumps, bearers, and joists, house re-levelling, and temporary support during the work. All structural timber framing must comply with AS 1684 Residential Timber-Framed Construction. Engineering is typically required for restumping and any load-bearing modifications, and may be quoted separately.
Materials include replacement stumps (concrete or steel screw piles), new bearers and joists where needed, and fixings. Perth's generally sandy soils make excavation for new stump footings straightforward in most suburbs, though coastal limestone and clay pockets in specific areas create exceptions. Labour remains the dominant cost component.
What Affects the Cost
- Number of stumps. A partial restump of 10–15 stumps is significantly cheaper than a full-house restump of 40–60 stumps.
- Stump material. Concrete stumps are the standard option. Steel screw piles cost more per unit but can be driven into sandy or limestone ground without excavation.
- Crawl space access. Perth has a mix of raised timber-floored homes and slab-on-ground construction. For raised homes, generous subfloor clearance reduces labour time. Low-clearance subfloors make the job harder and slower.
- Timber damage extent. Isolated rot in a few bearers is a contained repair. Widespread termite damage or prolonged moisture exposure affecting multiple structural members substantially increases the scope.
- Engineering requirements. An engineer's assessment adds $500–$1,500+ to the project. Load-bearing wall removals always require full engineering design.
- Soil conditions. While Perth's Bassendean sands are stable and easy to work in, limestone subgrade in coastal suburbs (Fremantle, Cottesloe, Scarborough) and clay soils in some eastern suburbs (Midland, Mundaring) present different foundation challenges.
- Termite history. Perth has significant termite activity, particularly in suburbs near bushland. Termite-damaged structural timbers need full replacement, and ongoing termite management should be part of the repair plan.
Replacing a cluster of failed stumps under a raised home on sandy soil with good crawl space access sits toward $2,850. A full-house restump with bearer and joist replacement, steel screw piles, engineering, and termite remediation in a home with limited access sits toward $23,750.
Perth-Specific Considerations
Older Fremantle homes. Fremantle, East Fremantle, North Fremantle, and White Gum Valley have some of Perth's oldest housing stock, with many homes dating from the 1890s–1930s. These are predominantly raised timber-framed homes on timber or early concrete stumps. After 90–130 years, original stumps are well past their expected lifespan. The limestone subgrade common in the Fremantle area adds a complication: new stump footings may need to be designed for limestone rather than sand, and excavation into limestone is slower and more expensive than digging in sand.
Sandy soils across most of Perth. The Bassendean and Spearwood sand systems that underlie most of Perth's suburban sprawl provide stable, free-draining ground for foundations. This means stump movement from soil reactivity is less of a problem in Perth than in Melbourne or Adelaide. However, sandy soils provide minimal resistance to termites, and the lack of a clay barrier means subterranean termites have relatively easy access to subfloor timbers.
Termite risk in Perth. The Perth metropolitan area has high termite activity, particularly in suburbs near bushland or older established areas with mature trees. Suburbs like Mundaring, Kalamunda, Roleystone, and areas backing onto Kings Park regularly deal with termite-related structural damage. Any structural repair should include a thorough termite inspection, and replacement timbers should be treated or termite-resistant species where possible.
Slab-on-ground construction. Much of Perth's post-1970s housing is slab-on-ground, which eliminates traditional restumping but introduces different structural issues. Cracking in slab foundations, particularly on clay soils in the eastern foothills, requires underpinning rather than restumping. This is a different trade (typically a specialist underpinning contractor rather than a general carpenter or builder) and is not covered by standard restumping pricing.
Coastal suburbs. Cottesloe, Scarborough, Trigg, City Beach. Salt air exposure accelerates corrosion of metal fixings and brackets in the subfloor. Stainless steel or galvanised fixings are recommended for structural work in coastal locations, adding a modest premium to the materials bill.
Hiring a Licensed Carpenter in WA
In Western Australia, builders performing structural work must be registered with Building and Energy (DEMIRS). Registration is required for work that needs a building permit or is valued over $20,000. Verify registration through the Building and Energy online register.
Ask for:
- Current WA builder registration number (verify it online)
- Proof of public liability insurance
- A written quote specifying the scope, materials, and whether engineering is included
- Confirmation of building permit requirements
- Evidence that termite management has been considered
Red flags: No builder registration, reluctance to involve an engineer for structural work, or no mention of termite inspection when working on subfloor timbers. In WA, home indemnity insurance is required for residential building work over $20,000.
How We Calculate
Estimates are based on current registered builder and carpenter rates across the Perth metropolitan area, adjusted for material and engineering costs in WA. All prices include GST. Figures cover standard residential structural repair work on raised timber-framed homes. Slab underpinning, heritage-listed properties, and commercial buildings may fall outside these ranges.