Structural Timber and Material Comparison
Understanding the materials your builder specifies helps you evaluate quotes and know what you are paying for.
When You Need Structural Carpentry
Not every crack or squeak means structural failure, but some signs warrant a professional inspection sooner rather than later:
Bouncy or springy floors when walking, particularly in the centre of rooms, suggest bearers or joists are undersized, overloaded, or deteriorated.
Floors sloping toward one side or corner of the house indicate differential stump settlement, where some stumps have moved or deteriorated more than others.
Doors and windows that stick or will not close when they previously worked fine point to the frame shifting as the subfloor moves. If doors or timber windows need replacing after the structure is stabilised, allow $300–$6,400 per job for
door and window replacement separately.
Visible cracks in plaster walls, particularly above doorframes and at wall-ceiling junctions, often track back to foundation movement.
Gaps between skirting boards and floors that you can see daylight through are a sign that the floor frame has dropped away from the walls.
Visible rot, termite damage, or crumbling material under the house, on stumps, or on bearers and joists when you inspect the subfloor. If moisture diagnosis identifies a need for
subfloor waterproofing, allow $500–$12,200 per job separately from timber repairs.
An engineer or experienced builder can assess whether the issue is cosmetic (settlement that has stabilised), active (ongoing movement), or structural (requiring repair). A structural inspection report typically costs $490–$1,000 for a residential property.
What Affects the Cost
Number of stumps. Across those 12 homeowner-reported quotes and costs, whole-house restumps covered about 45 to 146 stumps and totalled $11,000–$38,000. Three reports for replacing just 2–7 stumps worked out at ~$350–$850 each.
Stump material. Concrete stumps are the traditional replacement. Steel screw piles install faster and perform better in reactive clay soils because they anchor past the reactive zone. Galvanised steel adjustable posts are popular in Queensland for high-set homes. Six homeowner-reported quotes from 2020–2026 worked out at ~$600–$1,400 per stump for steel stumps on drilled piers or high-set Queensland homes.
Crawl space access. Subfloors with 500mm+ clearance allow workers to move around efficiently. At 300mm or less, every task takes significantly longer. Some homes have sections with almost no access, requiring floorboard removal from above.
Extent of timber damage. Localised rot in one or two bearers ($500–$1,000 per bearer replaced) is a contained repair. Widespread damage from termites or prolonged moisture exposure can mean replacing the entire subfloor frame, with hardwood joists at $20–$50 per lineal metre for materials alone.
Engineering requirements. A structural inspection ($490–$1,000) is the starting point. A full engineering design with beam calculations, footing specifications, and bracing requirements for a load-bearing wall removal can run $1,500–$3,000+.
Asbestos risk. Pre-1990 homes may have asbestos sheeting in subfloor areas, behind cladding, or as part of the flooring system. Licensed asbestos removal is required before structural work can proceed, typically adding $1,500–$5,000 depending on the extent.
Soil conditions. Reactive clay soils (common in Melbourne's west, Adelaide's north and south, and parts of Brisbane) cause stump movement over time. Sites classified H1 or above under AS 2870 may require deeper footings, longer screw piles, or engineered footing designs.
Replacing a handful of failed stumps under a raised home with good crawl space access on stable ground sits toward $3,000. A full-house restump with bearer and joist replacement, steel screw piles, asbestos removal, and engineering in a home with tight subfloor access on reactive clay pushes toward $36,400.
City and Regional Price Comparison
Sydney sets the baseline. Melbourne has the highest volume of restumping work nationally, driven by tens of thousands of post-war timber-floored homes on reactive basalt clay soils across the western and northern suburbs. Brisbane has strong demand for Queenslander restumping, where high-set homes provide generous working height that keeps labour costs more predictable than low-set southern homes.
Smaller trade pools and materials logistics affect structural repair quotes in Perth and Adelaide; see the Pricing by City table for local ranges. Perth's Bassendean sand systems provide stable ground in most suburbs, but limestone subgrade in the Fremantle area and clay pockets in the eastern foothills create exceptions. Adelaide's reactive clay soils, particularly in the northern plains (Salisbury, Elizabeth) and southern suburbs (Morphett Vale, Reynella), drive persistent restumping demand.
Within any city, cost variation comes down to the specific property. A raised home on stable soil with generous crawl space and localised damage is the best-case scenario. A low-set home on reactive clay with tight access, widespread damage, and asbestos present is the worst case. Inner-city terraces with sandstone foundations (Sydney), heritage homes with original timber framing (Melbourne), and high-set Queenslanders on 140-year-old hardwood stumps (Brisbane) each present distinct structural challenges. An engineer's inspection is the only reliable way to scope structural work before committing to a price.
For homes where the structural work involves plumbing or electrical disconnection and reconnection (common during restumping or load-bearing wall removal), those trades will be quoted separately.
How We Calculate
Estimates are based on surveyed trade rates for licensed builders across Australian capital cities, adjusted for regional labour markets and material costs. All prices include GST. Figures cover standard residential structural repair work. Commercial buildings, heritage-listed properties, and multi-storey structures may fall outside these ranges. Material costs reference current supplier pricing from WoodSolutions and Master Builders Australia member data.