The direct answer is: the best way to re-level a house in New Zealand depends on why the house has moved, the type of foundation, the soil conditions, how severe the movement is and whether the movement is still active.

Some homes may be suitable for non-invasive foundation repair methods such as resin injection, ground improvement, void filling or slab lifting. Other homes may require traditional underpinning, excavation, structural support work or a combination of repairs.

Mainmark New Zealand helps homeowners identify the cause of house movement and recommend practical foundation repair and house re-levelling solutions based on the property, ground conditions and level of settlement.

House re-levelling is the process of correcting, lifting or re-supporting parts of a home that have moved out of level.

This may involve improving support beneath the foundation, lifting sunken concrete slabs, filling voids, strengthening weak ground or addressing settlement beneath part of the structure.

Not always, but the two are closely linked.

House re-levelling focuses on improving the level of the home. Foundation repair focuses on addressing the support system beneath the home. In many cases, a house cannot be properly re-levelled unless the foundation or ground issue is also addressed.

Learn more about our foundation repair solutions 

No. Cosmetic repairs deal with visible symptoms such as cracked plaster, damaged tiles, gaps around trims or doors that do not close properly.

House re-levelling deals with the movement that may be causing those symptoms. If the underlying ground or foundation issue is not addressed first, cosmetic repairs may crack, shift or fail again.

For some homes, this may involve resin injection foundation repair to improve ground support and carefully lift affected areas. For others, it may involve ground improvement, slab lifting, void filling, traditional underpinning or structural repairs.

There is no single best repair method for every home.

The right solution depends on:

• The foundation type
• The soil conditions beneath the home
• The location and extent of settlement
• Whether the home is on a slab, piles, footings or mixed foundations
• Whether the movement is active or historic
• Site drainage and moisture conditions
• The severity of cracks, slopes or structural movement
• Access around and beneath the home
• Whether earthquake-related ground impacts are relevant

This is why Mainmark New Zealand assesses the site before recommending a foundation repair or house re-levelling option.

Soft, weak or variable ground

Some homes are built on ground that does not provide consistent support across the whole footprint of the house. If one section settles more than another, floors can become uneven and walls may begin to crack.

Poor drainage and water movement

Poor drainage is a common contributor to foundation movement NZ homeowners should take seriously. Water pooling near foundations, blocked gutters, leaking pipes or poor stormwater management can soften or wash away supporting soils.

Changing moisture levels

Soils can change as they become wetter or drier. Heavy rainfall, long dry periods and changing moisture levels may affect how the ground supports a home.

Coastal or filled ground conditions

Homes in coastal areas, low-lying areas or on filled sites may be more vulnerable to settlement if the ground is variable or not evenly compacted.

Earthquake-related ground movement

In some regions, including parts of Canterbury and Wellington, earthquake-related movement, historic settlement or liquefaction-prone ground may be relevant. Not every uneven floor is earthquake-related, but local ground history should be considered.

Voids beneath slabs or foundations

Voids can form beneath concrete slabs, footings or foundation areas because of washout, erosion, leaking services or poor compaction. Once support is lost, part of the slab or foundation may sink.

However, when several warning signs appear together, it is worth arranging an assessment.

They can be. Uneven floors in a house may suggest foundation movement if the slope is new, worsening or concentrated in one part of the home.

Homeowners should look for:

• Uneven floors in the house
• Sloping floors or floors that feel dipped
• Floor levels uneven between rooms
• Cracks in walls NZ homeowners have not noticed before
• Cracks around windows and doors
• Sticking doors and wall cracks appearing together
• Doors that no longer latch properly
• Windows that jam or do not close easily
• Gaps around windows, doors, skirting boards or ceilings
• Cracks in brickwork or exterior cladding
• Stair-step cracks in masonry
• Visible sinking or settlement around one part of the home
• Sunken concrete paths, patios, garages or driveways

The most important thing to watch is change. Has the slope appeared recently? Are cracks widening? Are doors getting harder to close? If the answer is yes, the issue should be assessed.

Resin Injection Foundation Repair

Resin injection foundation repair is a modern, non-invasive method used to improve support beneath affected foundations or slabs.

Engineered resin is injected through small injection points into the ground beneath the affected area. As the resin expands, it can fill voids, compact weak ground and, where suitable, help lift or re-level the structure.

Learn about Mainmark’s Teretek Resin Injection 

Can resin injection re-level a house without major digging?

In many cases, resin injection may reduce the need for disruptive excavation. This can make it a practical option for some homes affected by settlement, subsidence, weak ground or sinking slabs.

However, resin injection is not suitable for every property. The foundation type, soil conditions and extent of movement all need to be assessed first.

Ground Improvement NZ

Ground improvement focuses on improving the soil that supports the home.

This may be suitable where weak, loose, variable or poorly compacted ground is contributing to foundation movement. Ground improvement can help strengthen the support beneath affected areas and reduce the risk of ongoing settlement.

For New Zealand homes, this may be relevant in areas with soft soils, filled land, coastal conditions, variable ground or earthquake-related ground impacts.

Learn about our Ground Improvement solutions 

Slab Lifting

Slab lifting may be used when a concrete slab has dropped or become uneven.

This can apply to internal concrete floors, garages, driveways, patios, paths or other concrete areas around the home. If the issue is limited to the slab rather than the entire building foundation, slab lifting may be an effective repair option.

Learn about our slab lifting solutions 

Void Filling

Void filling is used when empty spaces have formed beneath slabs, floors or foundation areas.

These voids may be caused by erosion, washout, poor compaction, leaking pipes or water movement. Filling the voids helps restore support beneath the affected area.

Learn about our slab lifting solutions

Traditional Underpinning

Traditional underpinning involves strengthening or extending foundations, often through excavation and deeper support. This may be required where foundations need to transfer loads to stronger ground or where structural support has been significantly compromised.

Underpinning can be effective, but it may involve more disruption, more excavation and longer construction time than some non-invasive foundation repair options.

Learn about our resin injection underpinning 

Other Structural Support Solutions

Some homes may require a combination of foundation repair, drainage improvements, pile repairs, framing repairs, structural strengthening or engineering input.

This is why an assessment is important before deciding on the repair method.

It may be worth asking:

• Has one area of the home dropped?
• Are floor levels uneven in a specific section?
• Are wall cracks appearing near the affected area?
• Are doors or windows sticking nearby?
• Has a garage, patio, path or slab sunk?
• Is access around the home limited?
• Would avoiding major excavation reduce disruption?

Mainmark New Zealand may recommend non-invasive options such as resin injection, ground improvement, void filling or slab lifting where the site conditions support this approach.

Underpinning, excavation or another structural repair method may be required when:

• Foundation movement is severe
• Deeper structural support is needed
• The foundations are damaged or inadequate
• The movement is widespread
• The home has complex foundation conditions
• Piles, footings or structural elements require repair
• Drainage or erosion issues need major remediation
• Engineering requirements call for a specific structural solution

A reliable foundation repair specialist should explain the benefits and limitations of each method rather than recommending the same solution for every home.

Should I patch cracks before re-levelling?

Usually, it is better to assess the cause first. If the cracks are related to foundation movement, they may reopen after patching.

Should I replace flooring to hide uneven floors?

New flooring may make the room look better, but it will not fix a sinking foundation, weak ground or uneven slab below.

Should I trim doors that are sticking?

Sometimes a sticking door is minor. But if it appears with cracks or sloping floors, trimming the door may hide a useful warning sign without addressing the movement.

Foundation repair and house re-levelling help deal with the cause. Cosmetic repairs can then be completed with more confidence.

• Uneven floors have appeared recently
• Sloping floors are getting worse
• Wall cracks are spreading or widening
• Doors and windows are sticking
• Cracks in brickwork are visible outside
• Gaps are appearing around windows or doors
• One section of the house appears to be sinking
• You are renovating, buying or selling a home
• The property has drainage or subsidence concerns
• The home is in an area with known ground movement or earthquake-related issues

A site assessment helps determine whether the issue is cosmetic, historic or related to active foundation movement.

The team helps homeowners understand what is happening beneath their home and whether the issue may be caused by weak ground, settlement, voids, subsidence, poor drainage, changing moisture conditions or earthquake-related ground impacts where relevant.

Mainmark’s solutions may include house re-levelling, foundation repair, resin injection, ground improvement, void filling, slab lifting, underpinning alternatives and structural support solutions.

For homeowners in Auckland, Wellington, Christchurch, Tauranga, Hamilton, the Bay of Plenty, Canterbury and other parts of New Zealand, Mainmark provides practical assessment and repair options based on the property’s site conditions.

Learn about Mainmark Ground Engineering 

Contact Mainmark New Zealand to arrange a site assessment. Our team can inspect the signs of movement, consider the ground and foundation conditions, and recommend a practical repair option for your home.