Resin Injection

Resin injection underpinning is a method of foundation repair. The injection process is simple – the solution is injected into the building or house foundations. Once the solution reaches the surrounding soil, it expands. This method compresses the existing soil while filling in any cracks and voids.
It’s used to reinforce or repair foundations, underground tunnels and pipes. It fills in the gaps to make it watertight and stronger. There are different types of underpinning; concrete underpinning requires excavation and laying fresh concrete to stabilise a structure. The modern and more efficient method is chemical underpinning. Chemical underpinning utilises resin injections to address structural repair.
It can be used to address a variety of foundation problems, including:

Whether you have cracked walls or sloping floors, a structural assessment can determine the serious issue and which underpinning solutions suit your situation. A reliable underpinning contractor, like R+R, will review the structural design and assess wall cracks, water leaks, windows and doors, jammed doors, rising dampness, tree roots, leaning walls, or a leaning house.

There are obvious issues that chemical underpinning can repair – from sinking floors, drives, and paths to jammed windows and doors and even wall crack repair. It’s an effective alternative to traditional underpinning and can address the most common foundation problems. 

There are several factors to consider before you decide on the best course of house levelling action. There are a variety of causes of weakening or unstable ground – it could be down to soil types, seismic activity, soil erosion due to flooding, excessive load, weak soil, poor workmanship or nearby excavation work. 

Traditionally, underpinning can be a dangerous choice in reactive clay soils. The Australian Standard for footings and concrete slabs is to avoid traditional underpinning methods when dealing with reactive clays or soils. Other forms of foundation repair include concrete or steel piles beneath the existing foundation, concrete piers in the case of sinking piers, and slab jacking or slab lifting in extreme cases.

With resin underpinning, it’s a non-disruptive process that improves the ground engineering. It’s a quick stabilisation method, and it’s suitable for a wide range of building types. It can restore the foundation to its original condition, providing stability, strength, and durability. It’s a more environmentally friendly solution and requires no excavation. 

However, there are disadvantages, as a sizeable unground void will require a much larger resin quantity, making it a more expensive solution than anticipated. 

Traditional underpinning methods also strengthen the foundation and structural integrity of a building. Many of these methods are tried and true and have been used for over a century, but they can only deal with some types of subsidence. 

Ultimately, the process can be slow, with concrete underpinning potentially taking months. Excavation work is required, which means many areas will be out of use until the project is complete. 

In a battle between mass concrete underpinning vs. resin injection, the speed, efficiency and cost of underpinning with resin is unparalleled. While concrete underpinning involves excavating, injection underpinning is a straightforward process that takes as little as two days.

Clients choose Raise + Relevel for reliable, efficient, and high-quality underpinning services. Our team combines structural engineering knowledge, advanced resin injection technology, and years of hands-on experience to deliver permanent foundation solutions.

We prioritise minimal disruption — many jobs can be completed without excavation, allowing homeowners to remain in the property during the process. Our resin injection techniques provide fast stabilisation, while our concrete underpinning options ensure long-term structural protection.
Our commitment to customer service, detailed assessments, and transparent communication ensures every project is managed with precision. We stand behind our work with guaranteed results, giving homeowners confidence in the stability and safety of their property.