How to choose a remedial or underpinning contractor
The checks worth doing before you hire, from licensing and engineering to how a quote should be written, so you back the right contractor for a structural job.
Underpinning and concrete cancer repair are among the higher-stakes jobs a homeowner commissions: they are structural, expensive, and hard to put right if done badly. The good news is that a short set of checks separates a reliable remedial contractor from a risky one. Do them before you sign, not after.
Licensing and insurance
Structural and underpinning work is regulated building work in every state, so the contractor should hold the appropriate builder or trade licence for structural work, which you can verify with your state regulator, for example NSW Fair Trading or the Victorian Building Authority. Confirm they carry current public liability insurance and, where the job size requires it, home warranty or builder's warranty insurance. Ask for the licence number and check it yourself rather than taking a logo on a website at face value.
Engineering and method
For any structural movement, the repair should be based on an independent structural engineer's diagnosis and design, not just the contractor's opinion. Ask who is providing the engineering and whether the underpinning will be designed and certified by a qualified engineer. A contractor confident in their work will welcome an engineer's involvement; one who dismisses it is a warning sign. Make sure the proposed method actually matches your problem, and if two contractors propose different methods, ask each to explain why theirs suits your soil and footing.
How the quote should read
A good quote is specific. It should state the method, the number of piers or injection points, the design load, what is and is not included, how the site will be reinstated, and what monitoring or guarantee follows. Be cautious of quotes given without a site inspection, prices far below the others, pressure to decide on the spot, or large up-front deposits. Ask for references or recent local examples of the same kind of work, and get the scope in writing.
Finally, get more than one quote, but compare them on substance rather than price alone. The cheapest quote that skips the engineering, or a concrete repair that ignores waterproofing, is the one most likely to cost you again.
Common questions
Do underpinning contractors need to be licensed?
Yes. Structural and underpinning work is regulated building work in every Australian state, so the contractor should hold the appropriate builder or structural trade licence, which you can verify with your state regulator. Confirm current public liability insurance and, where required, warranty insurance, and check the licence number yourself.
Should the underpinning be designed by an engineer?
For genuine structural movement, yes. The repair should be based on an independent structural engineer's diagnosis and design, and ideally certified on completion. This protects you, keeps every contractor quoting on the same basis, and gives you documentation if you sell the property later.
Sources
- NSW Fair Trading, hiring a builder and licence checks
- Victorian Building Authority, using a registered practitioner
Prices are indicative guides only, not quotes. Confirm cost and method with a licensed contractor after an inspection.
Ready to get quotes?
Tell us what you are seeing and roughly where the property is. We will match you with a remedial or underpinning contractor serving your area. It is free and there is no obligation.