0800 873 835
New Zealand
The Cost Of Underpinning in Wellington in 2025
Underpinning is a critical solution for addressing sinking foundations, cracked walls, and subsidence issues in New Zealand. It restores the structural integrity of your home.
However, the cost of underpinning can vary significantly depending on the method used, the extent of damage, and several other factors.
Here’s a breakdown of what you need to know about underpinning costs, including modern alternatives like resin injection technology.
Resin underpinning is generally more cost-effective compared to traditional methods due to its efficiency and lower labour requirements. You can expect the average residential underpinning job cost to be anywhere between $4,000 and $15,000*.
Get a quote
Arrange a site assessment in 3 simple steps:
Step 1
Submit your enquiry using our online form. Include a brief message about the type of foundation issues you are experiencing.
Step 2
Our friendly customer service team will be in touch to schedule a site assessment that suits you.
Step 3
One of the Mainmark experts will visit your commercial property, assess the damage, and ascertain the likely cause. They will establish the approach needed, creating a plan specific to the needs of your building and provide you with a detailed quote.
Resin injection to raise, re-level and re-support a house in New Zealand
Structural expanding resin injection raises, re-supports, and re-levels sunken home foundations fast, economically and with a minimum of disruption to occupants.
Underpinning by resin injection means building footings are raised and returned to correct levels rapidly, compared to traditional concrete underpinning methods.
An expanding resin mix is injected through tubes into the ground beneath the footings. On entering the ground, the components mix together and expand by chemical reaction. The expansion force fills any voids that are present, aggressively chasing into any cracks or crevices in the soil, filling them tightly. The expanding resins also help compact any weak ground. That action provides the house or other building with renewed support.
If raising and re-levelling is required, the slab injection is continued, with the expansion acting upwards to bring the structure to its required level. Underpinning with resin injection is tightly-controlled with constant monitoring by laser leveller or similar means. Wherever possible, the injection is done from outside the house through 16 mm diameter tubes. When injection must be done from indoors, it is done through tubes of only 6mm diameter placed as inconspicuously as possible. That way there is minimal intrusion into the property and minimal interruption to the occupants.
The process is extremely rapid: most house rectification takes less than a day and hardly ever takes more than two days. Mainmark’s methods involve no demolition, no excavation, no water, and very little or no mess.
Re-level and re-support industrial buildings, floors and driveways
Factory and warehouse buildings, floors and driveways may all develop problems due to loss of ground support.
Most subsidence problems can be fixed quickly and economically by expanding structural resin injection with minimal interruption to your work. The process, often referred to as slab lifting, or concrete floor lifting, is fast and clean: no excavation, no water, no cement dust, no mess: unlike concrete underpinning. You don’t have to wait days for new cement to dry and to cure. Your forklifts, pallet jacks, and trucks can operate over the area just 30 minutes after we finish the slab injection. Moving and sunken slabs can usually be re-supported, re-levelled, and saved, unless too badly cracked. In a complex situation our experienced technical people can advise you about what can be saved and what should be replaced.
Structural expanding resin can re-level sunken slabs and re-support moving slabs in driveways, parking areas, garages, hardstand areas, and loading docks quickly, accurately and economically. With underpinning by resin injection, it generally takes only a few hours to level driveways, loading docks, hardstand areas and parking areas. Even the heaviest vehicles – forklifts, trucks and airliners – can run smoothly just 30 minutes after foam underpinning is completed. There is minimal interruption to traffic flow.
Resin injection to compact and strengthen deeper ground
In the past Mainmark used the Uretek Deep-Injection process, where structural resin fillers were injected via long tubes to various depths in the ground.
Since 1995, Mainmark has been using resins to compact and strengthen ground. Building on this experience we have developed and perfected our own unique and proprietary Teretek® deep-lift process for ground improvement and structural re-levelling. In certain ground conditions the bearing capacity of the ground can be increased this way by up to 500 per cent.
Our proprietary Teretek® deep-lift process can assist in liquefaction mitigation by densifying foundation ground. The pressure of the expanding resin compresses the surrounding soil until it can no longer be resisted by the counter-force of the structure and soil mass above, and the friction angle of the soil.
Slab-lifting or concrete floor lifting was sometimes used in conjunction with Uretek Deep-Injection.
Benefits & Features
Mainmark’s Solutions & Technologies
Fast
Our technologies have fast curing times and treated areas can be used immediately or without the delays compared to traditional repair methods.
Environmentally Inert
Our technologies use an inert material that is non-toxic and does not leach into the environment or affect the treated area.
Non-Invasive
Our solutions are of surgical nature compared to traditional methods.
Cost-Effective
Compared to traditional methods, our solutions are more cost-effective, with minimal disruption to the area.
Get a quote
Arrange a site assessment in 3 simple steps:
Step 1
Submit your enquiry using our online form. Include a brief message about the type of foundation issues you are experiencing.
Step 2
Our friendly customer service team will be in touch to schedule a site assessment that suits you.
Step 3
One of the Mainmark experts will visit your home or property and assess the damage. They will establish the approach needed, create a plan specific to the needs of your building and provide you with a detailed quote.
"*" indicates required fields
