Sinking Floors and Structures

 

Sinking Floors

What does a sinking floor mean?

Sinking concrete floors are an indication of building subsidence (when the ground sinks due to movement of underground material). A building can sink at various points or the collapse can be spread across the entire footprint of the foundation, depending on where the affected ground is and how large an area it is. This can be very serious, and if left untended is likely to worsen, creating further building subsidence and other consequent damage.

Gap between floor and wall in a house before remediation with Uretek structural resin injection

Gap between floor and wall in a house, before remediation from Mainmark

Gap between floor and wall in a house after remediation with Uretek structural resin injection

Gap between floor and wall in a house, after remediation from Mainmark

What causes subsidence?

There are many different causes of subsidence and various contributing factors. All involve some sort of change in the ground, which, in turn, generates movement of the soil. For example, droughts dry the ground, resulting in the soil (especially clay) contracting. Seismic activity shakes the ground, often resulting in liquefaction which ‘squeezes’ liquid up from the ground. Excavation and construction, even heavy traffic and machinery vibration, can move, displace and alter the condition of the ground. As well, different types of ground are more affected by different conditions. For example; clay is particularly prone to contracting in drought conditions, gravel and stony grounds can be more affected by nearby excavation, and excess water has a softening effect on dirt. Subsidence can happen over large areas of land or in a small targeted area. It can occur over a lengthy period of time, or can be an immediate reaction to nearby activity or natural events. When ground has been affected, building subsidence is common. Foundations or footings are no longer ably supported, sinking due to weak ground.

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
  • Erosion
  • Earthquake and seismic activity
  • 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 sinking floors?

The only way to fix sinking concrete floors is to raise foundation, re-level and re-support the building. Mainmark specialises in concrete levelling. Level correction not only re-levels a building, but also strengthens any weak ground under and around the perimeter of the foundations, ensuring a stable base and helping to avoid any recurring sinking issues. Traditional level correction or “underpinning” methods involve excavating or digging up parts of the foundation, pouring in concrete, waiting for it to set and then jacking up the building off the concrete blocks.

This method can be:

  • time consuming (often requiring weeks or months)
  • messy
  • usually means you’ll have to vacate part or all of the building while tradespeople work

Mainmark methods are much friendlier, both to the building and to those that occupy it. Our non-invasive concrete re-levelling techniques are cost and time efficient.

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

Sinking Floors in Homes

Mainmark’s level correction methods which include concrete floor lifting and ground re-levelling are effective on buildings of any size, including residential homes. They also deliver successful results on driveways and paths. We have successfully re-levelled thousands of projects around the world.

If you have a sunken floor, you may need ground re-levelling. We visit your home, assess damage, and discover the cause. Our experienced engineers and technicians establish the approach needed, creating a plan specific to the needs of your house. As the building and its sunken floors are brought back to level, any internal and external wall cracks generally close up too. Most importantly, structural damage is resolved and, with a stable foundation, the future of the house is sound.

Our concrete floor lifting and repair solutions are cutting edge and the modern answer to the traditional way to underpin; it is like keyhole surgery compared to concrete underpinning.  Our ground re-levelling alternatives to underpinning are not just for concrete slab floors. We can underpin, raise, and relevel strip footings, raft slabs, and ‘Waffle-Pod’ slabs, plus we can infill slabs and driveways.

Benefits of Mainmark’s level correction methods:

  • Floors and buildings are brought back to level and sunken floors are corrected
  • Cracks in walls generally close up
  • Jammed doors and windows are freed up
  • We don’t make mess: there is no concrete dust, water, or anything else to clean up
  • There is minimal disruption
  • We don’t cause further damage to the house or the landscaping
  • With simple jobs, residents can stay in the home and may not even need to move furniture
  • Techniques are non-invasive: we don’t tear up floors or excavate ground
  • Our methods are very quick, completed in a fraction of the time of traditional methods, and simple residential work is often done in a day
  • The methods we use strengthen weak ground, so your home becomes level and more stable
  • The products and techniques we use have zero negative impact on the environment.

Mainmark level correction methods used on Homes:

Sinking Floors in Heritage Buildings

Mainmark has delivered successful results to hundreds of heritage buildings. Our concrete floor levelling methods are a great solution, for many reasons, not least of all raising, re-levelling and re-supporting the building gives it a new lease of life, allowing an historical structure to stand strong into the future.

Sinking floors can be common in heritage buildings, often due to old footings as well as subsidence. As the building and its floors are brought back to level, any internal and external wall cracks generally close up too. Most importantly, structural damage is resolved, and with a stable foundation the future of the building is sound.

Key benefits of Mainmark’s level correction methods include:

  • Floors and buildings are brought back to level
  • 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 historical integrity remains unaffected
  • Internal and external wall cracks generally close up, leaving only cosmetic treatment (plastering, painting and re-pointing brickwork)
  • Jammed doors and window can usually operate properly again
  • Methods are effective on various foundations, such as, bluestone, brick and sandstone
  • The methods we use strengthen weak ground, so the building becomes level and more stable.

Mainmark level correction methods used on Heritage Buildings:


Read about how we helped the Heritage listed Bank of New Zealand building in Christchurch stand strong.


"Before" photo of heritage-listed school in Sydney

This heritage-listed school in Sydney had lost ground support at one end, so the engineers called in Mainmark

"After" photo of heritage-listed school in Sydney

The heritage-listed school, re-supported and raised back to level, plus some sandstone replaced and joints re-pointed

Sinking Floors in Commercial and Industrial Structures

Mainmark methods can lift buildings of any size, having been used with great success on thousands of projects around the world. The level correction solutions we provide to the commercial and industrial sectors are sought for many reasons; a significant factor being how cost effective and time efficient the processes are.

Sinking floors can cause many problems in the Commercial and Industrial sectors, often with negative impact on equipment and machinery. Bringing the building and its floors back to level means everything is back on an even keel, optimising business output. Most importantly, structural damage is resolved, and the future of the building is sound. In fact, our methods actually improve the building’s bearing capacity. Mainmark methods are suitable for any building, of any size. We also re-level parking areas, loading docks, hardstand areas and driveway.

Key benefits of Mainmark’s level correction methods include:

  • 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 do not create 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
  • The methods we use strengthen weak ground, so the building becomes level and more stable.

Mainmark level correction methods used on Commercial and Industrial buildings:

Corner of a warehouse wall "before" level correction

Corner of a warehouse wall “before” level correction

The same corner of a warehouse wall showing the gap closed up "after" level correction

The same corner of a warehouse wall showing the gap closed up “after” level correction

Sinking Infrastructure

In the infrastructure sector, subsidence can fast cause havoc. Sinking structures, floors, and ground create numerous problems, and are likely to become hazardous if not resolved promptly and correctly.

Mainmark’s methods have delivered results to thousands of projects worldwide. We have successfully raised, re-levelled and re-supported sunken roads and highways, bridge approach slabs, bridge abutments, culvert areas, concrete slabs, airports, seaports, railways, parking areas, and many other civil works.

The level-correction solutions we provide are sought for many reasons; not least of which are the cost effective and time efficient processes we use.

Bringing the structure or approach slab back to level means everything is back on an even keel, optimising business output. Most importantly, structural damage is resolved, and the future of the structure is sound. In fact, our methods actually improve the structure’s bearing capacity. Mainmark methods are suitable for any building or structure, of any size. We also re-level parking areas, loading docks, hardstand areas, driveways, and roads.

Key benefits of Mainmark’s level correction methods include:

  • There is minimum disruption to the site, no excavation and no mess
  • There is little, if any, downtime to the site: in many cases, it can still operate (this is case-dependent, site requirements may be such that this is not possible)
  • Projects are completed in a significantly faster timeframe than traditional methods
  • Non-invasive techniques mean further damage to the site, and the landscaping around it, is absolutely minimal. We don’t tear up areas or excavate ground, creating costly and time-wasting messes
  • Trip hazards are eliminated. Vehicles and machinery can run smoothly almost immediately
  • Re-levelling is completed in a fraction of the time of traditional methods. There’s no cutting out of old approach slabs and no waiting days for new slabs to cure
  • There are usually substantial cost savings, in comparison to traditional methods
  • Weight is no problem. In fact the greater the weight on the ground, the more it can be compacted. Huge ground support can be created, especially when the area is loaded with weight
  • There’s minimal interruption to traffic flow or activities to busy facilities, such as roads or airports
  • The methods we use strengthen weak ground, so the site becomes level and more stable.

Mainmark level correction methods used in the Infrastructure sector:

50mm drop in the slab at a busy seaport

The problem – a 50mm drop in the slab at a busy seaport

The slab is re-levelled and the container forklifts can run on it just 30 minutes later

The solution – the slab is re-levelled and the container forklifts can run on it just 30 minutes later

Sinking Structures in Mining and Resources

Sinking structures, floors and ground create many problems in the Mining and Resources sector. If not resolved promptly, and correctly, mine subsidence issues can cause costly downtime and even become hazardous.

For many years Mainmark methods have been used in raising foundation, re-levelling and re-supporting on-ground and in-ground mine-site structures, including:

  • Coal loader towers
  • Conveyer belt pedestal bases
  • Rock-breaker footings
  • Rail index machine slabs
  • Vehicle service centres & garages
  • Stacker reclaimer rails
  • Office buildings
  • Conveyer belt counter-weight towers
  • Railway lines
  • Engineering workshops
  • Parking areas
  • Loading docks

Mainmark methods are used successfully on any building, of any size.

Key benefits of Mainmark’s level correction methods include:

  • There is minimum disruption to the site, no excavation and no mess
  • Projects are completed in a time-frame significantly less than traditional methods
  • Non-invasive techniques mean further damage to the site, and the landscaping around it, is absolutely minimal. We don’t tear up areas or excavate ground, creating costly and time-wasting messes
  • Trip hazards are eliminated. Vehicles and machinery can run smoothly almost immediately
  • Re-levelling is completed in a fraction of the time of traditional methods. There’s no cutting out of old slabs and no waiting days for new slabs to cure
  • There are usually substantial cost savings, in comparison to traditional methods
  • Weight is no problem, in fact the greater the weight on the ground the more it can be compacted. Huge ground support can be created, especially when the area is loaded with weight
  • There’s minimal interruption to the site, operations can often continue while the work is being completed
  • The methods we use strengthen weak ground, so the site becomes level and more stable.

Mainmark level correction methods used in the Mining and Resources sector:

 

 

 

Tell us your problem:

Don't see the solution to your ground engineering problem here? Talk to us, we can help. For an extensive analysis of your specific problem please complete our detailed enquiry form, alternatively fill in our quick contact form to the right.

 

 

 AU: 1800 623 312    NZ: 0800 873 835

Quick Contact

(*) Compulsory Fields