What does unlevel buildings mean?

Unlevel buildings are the result of weak ground and/or subsidence.

The appearance of internal or external wall cracks, inability to open and close windows and doors, cracked floors and more can all signal an unlevel building. Once a building becomes unlevel, it is important to fix it right away, or risk further damage and potential hazards. This requires foundation repair, footing repairs, and house re-levelling.

Unlevel commercial and industrial structures

Mainmark can re-level structures of any size, including commercial and industrial structures. The processes are time- and cost-effective, making them sought after around the world. Unlevel commercial structures can result in damage to plant and machinery, occupational health and safety risks, and reduced efficiency if certain areas can’t be used. By levelling the structure, Mainmark resolves damage and brings the building back to full capacity, so businesses can regain that lost productivity.

From parking areas and loading docks to warehouses and office buildings, Mainmark’s methods are suitable for buildings of any size. We offer the award winning JOG Computer-Controlled Grouting solution. Extremely successful in re-levelling the Christchurch Art Gallery following an earthquake, this method is a computerised level correction system that involves, in sequence and rapid succession, grout injection via multiple injection ports. This creates multiple localised hydraulic forces, strategically-arranged over large areas, to effectively float a structure back to level.

What causes unlevel buildings?

A loss of ground moisture, such as in drought conditions, can cause buildings to subside and become unlevel. The weight of the building causes it to sink, but the nature of soil and clay shrinkage is that the foundation subsidence is never usually uniform. Loss of support varies across the structure, often causing cracks to form. Often, as the soil or clay becomes moist again and expands, some of the damage may be reversed. However, without ground compaction, all wall cracks are prone to reopen with the next extended dry period.

Earthquakes can cause unlevel buildings and soil liquefaction, which makes previously-stable soil behave like a liquid, causing buildings to become extremely unstable. In many cases the damage that caused the building to become unlevel happens over very long periods of time, making it difficult to pinpoint the exact cause. Regardless of the cause, subsidence repair is possible, and unlevel buildings can be re-levelled and re-supported.

Likely causes:

Water flooding the ground

Drought drying out soil

Washaways from broken pipes (such as water, sewer, stormwater drainage)

Poorly compacted fill

Liquid, gas or mineral resources being removed from the ground


Earthquake and seismic activity, often resulting in liquefaction

Tree roots can suck moisture from the ground

Vibrations caused by heavy road traffic or by machinery

Absence of an organised footing system – in very old buildings or in buildings with additions or alterations

Nearby excavation

Heavy loading

Deterioration of retaining walls

How to fix unlevel buildings?

Mainmark specialises in raising, re-levelling, and re-supporting unlevel buildings by treating the foundation subsidence beneath them which, in turn, allows for the foundation slab to return to level. For example, we can inject structural resins into the foundation ground under the building’s footings for foundation repair and footing repairs. The resins expand together chemically, creating pressure. That pressure lifts the building back to its correct level. Then, if there are weak layers in the ground, continuing injection at deeper levels can resolve this by compacting the ground, densifying and strengthening it to increase its bearing capacity for the future.

Alternatively, we can undertake our JOG Computer-Controlled Grouting for re-levelling. Extremely successful in subsidence repair, this award winning method was used to re-level the Christchurch Art Gallery after it suffered building subsidence following an earthquake. JOG is a computerised level correction system that involves, in sequence and rapid succession, grout injection via multiple injection ports. This creates multiple localised hydraulic forces, strategically-arranged over large areas, to effectively float a structure back to level. In some soil conditions, Mainmark can increase the bearing capacity of weak strata by as much as 500 per cent.

Mainmark’s concrete slab levelling methods are fast, efficient, and cost effective; they don’t require you to vacate the building while work is being done.

Various product warranties and Building Code requirements apply (please contact us to see which apply in your region or country).

Benefits of Mainmark’s building levelling methods:

There is minimum disruption to the site

There is little, if any, downtime to the business. In many cases, the site can still operate, with staff able to continue working (this is case-dependent, damage may be such that this is not possible)

Projects are completed in a time-frame significantly less than traditional methods

Non-invasive techniques keep further damage to the building, and the landscaping around it, to an absolute minimum

We don’t tear up floors and excavate ground, so don’t create any mess

Internal and external wall cracks generally close up, leaving only cosmetic treatment (plastering, painting and re-pointing brickwork)

Jammed doors and windows can usually operate properly again

Trip hazards are eliminated. Often, forklifts and trucks can run smoothly just 30 minutes after the floor is re-levelled

There’s usually no need to move stock or machinery off the floor. No excavation. No mess

Warehouse shelves and conveyor systems usually return to their correct positions as floors are re-levelled

Most large factory and warehouse floor repairs are completed in a day or two. There’s no cutting out of old slabs and no waiting days for new slabs to cure.

Mainmark ground stabilisation methods used for commercial and industrial structures: