Resinject resin injection: what to know

Grounded in Resinject's own published site and process pages. General information, not advice for your specific property.

A neutral look at Resinject's RSJ170 resin injection process, drawn from Resinject's own published materials: what it is, how Resinject compares it to traditional underpinning, and what its own cost page does and does not say about price.

"Resinject" is another name homeowners search for directly when researching resin injection, alongside Mainmark, so this page pulls together what Resinject itself publishes about its RSJ170 resin injection process, how it describes that process against traditional underpinning, and what its own cost page does, and does not, say about price. Remedial Building Help does not provide or resell Resinject's services; this is independent, informational content.

Who is Resinject

Resinject describes itself as a wholly Australian owned and operated family business, in operation as an underpinning company for over a decade, servicing NSW, QLD and the ACT, with some of its pages also naming regional Victoria. RSJ170 is Resinject's own engineered polyurethane resin, which the company says is 100% Australian produced and blended, and sold with a 50-year product warranty.

How Resinject's RSJ170 resin works

Resinject's own process pages describe RSJ170 as injected through small holes, 7mm or 16mm in diameter, with no digging required. The company says the resin expands up to 40 times its initial volume as it reacts, binding surrounding soil particles into what it calls a dense, composite material, and that the resin itself cures within 60 seconds of injection. Resinject states RSJ170 can reach depths exceeding 6 metres, and cites compliance with Transport for NSW's M232 specification for expanding-resin slab jacking and stabilisation.

Resinject's own comparison: resin injection versus traditional underpinning

Resinject's underpinning page draws its own contrast between what it calls traditional methods and its RSJ170 alternative. Traditional underpinning services, it says, "typically used concrete to add strength to the soil, but this was often invasive and time consuming." Resinject describes its own resin injections as "a less invasive, more cost-effective and time-efficient method of underpinning a house." This is Resinject's own framing of its product against a generic alternative, not an independent finding; for this site's own neutral, method-by-method comparison across all three underpinning families, see underpinning methods explained.

Where resin injection fits next to restumping

Resin injection, including Resinject's RSJ170 method, is a form of underpinning: it treats slab-on-ground and strip-footing homes, via resin injection improving the soil that supports them. Restumping and reblocking solve a different problem, older homes built on timber or concrete stumps rather than a slab, so the two remediations are not interchangeable for the same house. See underpinning, resin injection and restumping compared for how the methods line up across construction types.

What Resinject's cost page says

Resinject's own cost page gives $3,000 to $25,000 as a general guide for the cost of underpinning a house in Australia, a figure it introduces as depending on the method used among other site factors, rather than a resin-specific quote. For resin injection specifically, Resinject describes it without giving a separate dollar figure: it calls resin injection underpinning "often more affordable and less invasive than traditional concrete methods, where site conditions make it a suitable solution," and elsewhere on the same page describes chemical underpinning as able to be "significantly more cost-effective in suitable applications, often requiring less labour, less excavation, and a shorter installation time." For unit rates across other underpinning methods and how they compare, see the underpinning cost guide; a written, itemised quote for your own property is the only reliable number.

Before you hire Resinject or anyone else

Whichever company you are considering, including Resinject, confirm current licensing, insurance and a written, itemised scope directly with them before agreeing to work, and get an independent structural engineer's assessment first if the cause of movement is not already established. See how to choose a remedial contractor for the questions worth asking, or our directory to compare quotes from other listed underpinning and resin-injection providers.

Common questions

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