Common causes of a shifting house foundation

Queensland homes are known to experience subsidence due to sandy solis and extreme weather conditions. This can be evident by signs of sinking and cracked floors or concrete slabs, a crack in the wall or doors and windows that won’t close. Not attending to these issues could result in a safety hazard, significantly devalue your property or the need to invest additional costs to rectify foundation damage, particularly if left unaddressed. This is where Mainmark helps you choose the most appropriate techniques to rectify the issue. One of the most popular and cost-effective methods is resin injection; a more modern, but proven, method of underpinning and strengthening building foundations.

Queensland is a unique area of Australia with extended periods of rain and drought, sandy soils and other factors that impact coastal and inland ground conditions. In addition to extreme weather events, particularly around the coastal and flood zone prone areas, homes may be affected by the following causes of foundation problems:

  • Leaking pipes: over time pipes under properties tend to deteriorate, becoming damaged or blocked which then causes cracks, allowing water to seep into the ground, both around and directly underneath the property. Clay pipes and modern thin plastic pipes are known to be the common culprits. Leaky gutters and downpipes or dripping outdoor taps are also frequently identified as the source of water collecting near house foundations.
  • Inadequate drainage: excess water within the grounds of a property can cause weakening of ground and the structure to ultimately subside. Hence, moisture management is key for good foundation and footing maintenance.
  • Poor building work: where there is evidence of insufficient ground preparation, particularly with newer constructions, structures will often shift causing damage to walls, floors, doors and windows. This is usually when house underpinning is considered, as well as other costly remediation works for fixing cracks in walls, concrete slabs and driveways.
  • Adjacent development: as developers look to utilise every inch of land during construction, building or renovation works can affect neighbouring property. Stability of the soil is compromised when heavy machinery is used during construction which can have a knock-on effect on the soil on your side of the fence. This is even more problematic when coinciding with periods of heavy rain which soften the ground and may lead to soil erosion and voids. In addition, removal of any trees or vegetation can affect the water table as moisture is no longer drawn out of the soil by a tree’s roots.
  • Tree roots: maturity of trees can cause roots to damage pipes resulting in cracks or loose joints. Tree roots will naturally grow towards these areas in search for water. Eventually, aggressive root systems will infiltrate pipes causing blockages which cause water to spill into the ground, impacting the stability of house foundations.

The Mainmark solution

Mainmark offers some of the most advanced non-invasive resin injection and grout technologies to quickly correct foundation ground issues with minimal mess or disruption, perfected over more than 20 years in business. With a sound knowledge of Queensland’s unique local conditions, Mainmark utilises its Teretek® engineered resin injection solution to effectively raise, re-level, and re-support footings under a home. Teretek is a unique two-in-one solution that provides both ground improvement and re-levels homes, backed by a 50-year product warranty. It increases ground bearing capacity, fills voids, rehabilitates foundation ground which helps raise sinking floors and reduces wall cracking, all at a fraction of the cost of traditional underpinning, and with no detrimental effects on the environment. Mainmark has successfully raised and re-levelled thousands of homes and driveways throughout Queensland. The process is extremely quick; most house re-levelling and concrete slab lifting takes less than a day, and driveways and slabs can be driven on within hours once the application is complete.

A cost effective alternative

Underpinning homes is generally a costly exercise using traditional methods due to the invasive nature of concrete underpinning, which is generally a lengthy and messy process. Teretek is the modern way to raise, re-level and re-support your home by providing a unique two-in-one solution delivering both ground improvement and re-levelling. It’s applied like keyhole surgery and most jobs can be done in a day, usually reducing the cost of the works when compared to traditional underpinning. As every home is different, Mainmark finds the best solution to treat the root of the problem. The cost of each job will vary according to:

  • your location
  • the actual cause of the problem – what other things need to be resolved as part of the works eg. drainage
  • the nature and condition of the foundation soil – including an assessment of the soil type
  • the type and profile of the building footings – are the existing footings damaged or in need of replacement?
  • the surroundings e.g. access to the site, adjacent buildings or retaining walls
  • unknown or unforeseeable underground conditions – problem solving on site
  • the volume of material that will be required – an estimate will be provided but may need to be re-assessed following more detailed ground investigation
  • the time that the work will take – based on Mainmark’s extensive experience.

Why choose Mainmark?

Calling in experienced ground engineering consultants for an appraisal can help to quickly diagnose the issue and find a solution tailored to your home. Mainmark has raised, re-levelled and re-supported homes and buildings for over 20 years, delivering successful solutions to thousands of homes in Queensland from coastal to inland areas. Our solutions are cutting edge and the modern answer to the traditional way to underpin. We can underpin, raise and re-level strip footings and raft slabs, plus we can infill slabs and driveways. Mainmark’s proprietary product Teretek addresses building foundation problems, with minimal intrusion into the property and minimal interruption to the occupants, effectively underpinning by non-invasive expanding resin injection. In most cases, residents are not required to move out or move any furniture during the ‘home lift’ process. In contrast, traditional concrete can be a slow process; involve excavation which causes mess; can reduce bearing capacity; cause differential movement between the underpinned sections of the structure and the rest of the structure; and be labour intensive.

The Mainmark solution is:

Cost effective – no hidden fees or extra costs

Non-invasive – our process involves keyhole surgery, hence no major excavations

Resident friendly – work is carried out with minimal disruption, in most cases you won’t even need to move out!

Time efficient – on average we can get your home back to level in little as a day or within 1 – 2 weeks depending on the technologies we utilise

Worry-free – Worry-free – backed by an industry leading 50 year product warranty and a licenced builder that provides Home Warranty Insurance/Builders Warranty Insurance where required

Accurate – using state of the art technology our qualified technicians can re-level extremely accurately

Reputable – our specialised methods have been mastered for over 25 years with thousands of satisfied customers

Queensland by location

Queensland is known to have high concentrates of moisture in the soils, causing movement and instability in the ground. This can generally be attributed to the severe weather conditions it experiences from high rain fall and flooding, to extended dry periods. Property foundations around water – primarily beach, lake and river side homes – seem to be the most affected. The tell-tale signs normally consist of step cracks starting to appear on walls, floors and driveways sinking and/or cracking and jammed doors and windows. Foundation movement may also be caused by other underlying or site-specific issues which require a professional assessment and working knowledge of the local area.

  • Far North Queensland / North Queensland:

    Houses around the coastal area of northern Queensland are often built on sandy or silty soils that can compromise the strength of building foundations. The root cause can be attributed to insufficient ground compaction during construction, where soils shrink and swell due to adverse weather conditions. Sandy soils sometimes need permeation grouting in addition to resin treatment to strengthen the ground before a home is re-levelled. Areas affected by these conditions include Cairns, Port Douglas, Ingham, Cardwell, Innisfail, Magnetic Island and Townsville.

  • Central Queensland / Mackay, Isaac Region and Whitsunday Coast:

    Soil in these areas comprise of silty, clay and sandy soils, with properties near the coast most affected by erosion. Significant problems may occur following lengthy periods of extreme weather like droughts and floods. On sloping blocks heavily affected by rains, it may also be important to treat the ground underneath driveways and paths to prevent cracking and trip hazards. New developments are also susceptible to sinking, particularly when the ground may not have been prepared properly, resulting in the house settling. Teretek can improve the grounds bearing capacity prior/after construction. Areas affected by these conditions include Bowen, Airlie Beach, Mackay, Isaac Region, Rockhampton and Gladstone.

  • Wide Bay Burnett / South East Queensland:

    These areas contain a lot of larger blocks with single or double-storey homes that utilise concrete, masonry rock and stone foundations. Reactive clay soils are susceptible to expansion and contraction with varying soil moisture content which over time can cause these footings to sink. With new developments, removal of trees and shrubs around a building moisture levels can be affected causing settlement. Vibrations from neighbouring properties which are being developed may also cause ground disturbance and subsidence, aggravating wall cracks. Brisbane, Gold Coast, Sunshine Coast, Gympie, Maryborough and Bundaberg are likely impacted.