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, which provides span tables for bearers, joists, and lintels graded by timber stress grade (F7, F14, F17). Engineering is typically required for restumping and any load-bearing modifications, with a structural inspection running $490–$1,000.
Materials include concrete stumps ($400–$700 installed), steel screw piles ($500–$1,000 installed, able to be driven into sandy or limestone ground without excavation), and galvanised steel adjustable posts from brands like LevelMaster (bolted to concrete pads, fully above ground, eliminating termite and rot risk). Replacement bearers and joists run $20–$50 per lineal metre for hardwood (F17 jarrah or ironbark) or $8–$20 per lineal metre for treated pine (H3/H4). Perth builders often specify jarrah for structural replacement because it is locally sourced, naturally termite-resistant, and one of the most durable timbers available. Labour remains the dominant cost component, with Perth builder rates typically $70–$120 per hour.
What Affects the Cost
- Number of stumps. A partial restump of 10–15 stumps costs significantly less than a full-house restump of 40–60 stumps. For a standard small 3-bedroom home, a full restump runs $3,000–$9,000+, while larger homes with more stumps push higher.
- Stump material. Concrete stumps ($400–$700 installed) are the standard option. Steel screw piles ($500–$1,000 installed) can be driven into sandy or limestone ground without excavation, making them effective in the Fremantle limestone belt. Adjustable galvanised steel posts are a cost-effective option for accessible subfloors.
- Crawl space access. Perth has a mix of raised timber-floored homes and slab-on-ground construction. For raised homes with generous clearance (500mm+), restumping is relatively straightforward. Low-clearance subfloors (under 300mm) can add 30–50% to labour costs.
- Timber damage extent. Isolated rot in a few bearers ($500–$1,000 per bearer) is a contained repair. Widespread termite damage affecting multiple structural members substantially increases the scope.
- Engineering requirements. A structural inspection ($490–$1,000) is the starting point. Full engineering design for load-bearing wall removal (specifying LVL or steel beams, connections, and footings) runs $1,500–$3,000+. LVL beams from Wesbeam (E13/E14 grades) are locally manufactured in Neerabup, making them readily available and competitively priced in WA.
- Soil conditions. Perth's Bassendean sands are stable and easy to excavate. Limestone subgrade in coastal suburbs (Fremantle, Cottesloe, Scarborough) is harder and more expensive to excavate, adding $50–$150 per stump. Clay soils in the eastern foothills (Midland, Mundaring) can be reactive under AS 2870, requiring engineered footings.
- Termite history. Perth has significant termite activity. 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 on limestone subgrade with limited access pushes 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, many with original jarrah framing. After 90–130 years, original stumps are well past their expected lifespan, even though the jarrah bearers and joists above may still be in fair condition. The limestone subgrade common in the Fremantle area adds a complication: new stump footings must be designed for limestone rather than sand. Excavation into limestone is slower and more expensive than digging in sand. Companies like Heritage Restumping work extensively in these areas and understand the specific challenges of limestone foundations.
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 far less common in Perth than in Melbourne or Adelaide. Under AS 2870, most Perth sand sites are classified A (non-reactive) or S (slightly reactive), meaning footings can be simpler and shallower. The trade-off is that sandy soils provide minimal resistance to termites: the lack of a clay barrier means subterranean termites have easy passage from soil to subfloor timbers.
Termite risk in Perth's Hills suburbs. Mundaring, Kalamunda, Roleystone, Darlington, and areas backing onto Kings Park regularly deal with termite-related structural damage. The combination of mature eucalyptus, sandy soils, and moisture creates ideal conditions for subterranean termites. Any structural repair in these suburbs should include a thorough termite inspection ($250–$400). Replacement timbers should be treated (H3 or H4 treatment level) or naturally termite-resistant species like jarrah. A good builder will also recommend installing physical termite barriers (stainless steel mesh or chemical soil barriers) around new stumps.
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 and in some newer estates in the northern corridor (Ellenbrook, The Vines), requires underpinning rather than restumping. This is specialist work (typically a dedicated underpinning contractor rather than a general carpenter or builder) and is not covered by standard restumping pricing.
Coastal suburbs and salt air. Cottesloe, Scarborough, Trigg, City Beach, Swanbourne. Salt air accelerates corrosion of metal fixings and brackets in the subfloor. Stainless steel or hot-dipped galvanised fixings are recommended for structural work within a few kilometres of the coast, adding a modest premium to the materials bill. Coastal exposure also accelerates the weathering of exposed timber in the subfloor.
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.
A good structural builder will:
- Provide their current WA builder registration number (verify it online before signing)
- Carry public liability and home indemnity insurance (mandatory for work over $20,000 in WA)
- Give a written quote specifying stump material, bearer/joist species and grade, and engineering scope
- Confirm building permit requirements
- Include a termite management plan when working on subfloor timbers
Worth checking:
- Builder registration is current and covers the proposed scope
- The quote specifies whether jarrah, treated pine, or LVL is being used for bearers and joists
- Engineering is arranged for any restumping or load-bearing modification
- The termite inspection and management plan is included, not left as an afterthought
- For coastal properties, the quote specifies stainless steel or galvanised fixings
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.