Mainmark resin injection: what to know

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

A neutral look at Mainmark's Teretek resin injection process, drawn from Mainmark's own published materials: what it is, how Mainmark compares it to traditional underpinning, and where it differs from restumping.

"Mainmark" is one of the names homeowners search for directly when researching resin injection, so this page pulls together what Mainmark itself publishes about the process, how it says resin injection compares to traditional underpinning, and where resin injection fits alongside restumping. Remedial Building Help does not provide or resell Mainmark's services; this is independent, informational content.

Who is Mainmark

Mainmark describes itself as operating in Australia since 1989, offering "ground improvement, level correction, and void filling solutions," with a residential focus on addressing subsidence. Teretek is Mainmark's trademarked name for its resin injection method, one of the methods it offers alongside its other ground-improvement work.

What Mainmark's resin injection process involves

According to Mainmark's own description, the process delivers an expanding polyurethane resin into the ground beneath a footing or slab through small injection tubes, positioned according to what each project needs. As the resin expands, it fills voids and strengthens the ground, and Mainmark says further controlled injections can then be used to help bring the building back toward level. Mainmark describes the process as non-disruptive, with work on a typical house taking about a day, and describes its Teretek resin as water-resistant and chemically stable, and says it does not leach.

How Mainmark compares resin injection to traditional underpinning

Mainmark's own site draws this contrast between its resin injection method and what it calls the traditional approach. It frames resin injection as "a modern alternative to traditional underpinning" that can be "more targeted, less invasive and faster than excavation-based concrete methods, depending on the site conditions." This is Mainmark'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, including screw piles, see underpinning methods explained.

Resin injection versus restumping

Resin injection, including Mainmark's version, is a form of underpinning aimed at slab-on-ground and strip-footing homes. It is a different job to restumping or reblocking, the remediation used on older homes built on timber or concrete stumps rather than a slab, so the two are not interchangeable options for the same house. See underpinning, resin injection and restumping compared for how the methods line up across construction types.

What Mainmark says about cost

Cost is one of the more heavily searched questions about Mainmark specifically. Mainmark's cost page gives $4,000 to $15,000* as the average residential underpinning job, a figure introduced as a breakdown across its underpinning methods rather than a resin-specific quote; the source page's asterisk carries an unresolved footnote marker, so treat the figure as a general estimate. For resin injection specifically, Mainmark states the cost "varies based on the size of the property and the extent of foundation damage," without giving a dollar figure, while describing resin underpinning as generally more cost-effective than traditional methods due to its efficiency and lower labour requirements. 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 engage any provider

Whichever company you are considering, including Mainmark, 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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