Deep Pinning – some interesting facts…

  • Deep Pinning is a permanent repair which does not lose its effectiveness over time – the root cause of the problem is addressed, as well as the symptoms.
  • Most underpinning repairs we undertake are to footings which are well specified – even generous footings are susceptible to significant settlement if the foundation conditions change.  No footing can suspend itself above a settled foundation for more than a metre or two before breaking and allowing settlement.  Infact, concrete footings need to crack (on the tension side of the footing – typically the top face) before the internal steel reinforcing even starts to help the situation.  Often this consolidation, while deemed acceptable by the codes of Standards Australia, is enough for a brick wall to rotate outwards and cause significant cracking and destabilisation.
  • Requires far less concrete than alternative underpinning methods, which in doing so, apply additional pressure on the already unreliable soil profile and leave the footing susceptible to further movement should ground conditions keep changing.
  • Can be easily customised in the number of load-bearing pins installed and varying ‘angle from vertical’ to suit on-site loading and geological variations, providing an efficient solution every time.  Deep Pinning has penetrated through firm clay, swampland and deep sandunes to name a few, many as deep as 22m.
  • The process of underpinning over an area produces a defined ‘bedrock depth profile’ which allows any premature refusal on ‘floaters’ or other unreliable strata to be identified as a clear deviation from the norm and structural compensations made.  In addition, the softness of the profile at various depths invariably pinpoints the location of the failure layer so that repairs can be made to leaking pipes or drainage issues.   This action thereby prevents the problem from spreading to other footings.  Logging of the depth where soft layers exist allows upstream cut-off drain depths to be specified so seepage can be intercepted in an attempt to protect the remainder of the property.  It provides a full soil profile health assessment.
  • Several clients in recent years have had their underpinning FULLY COVERED by their house insurance due to our unique ability to confidently identify the scope of the below-ground issues and the ultimate cause.  Deep Pinning not only fixes the problem – guaranteed – it can be virtually free…
  • Alternative underpinning systems are often more costly, less effective and include limitations, exclusions and legal disclaimers simply because they stop short of addressing the cause of the failure.  Why  compromise when a superior solution is available?
  • The Deep-pinning Advanced Underpinning System was conceived, developed and patented by a Specialist Geotechnical Engineer working in Hobart, Tasmania, Australia and carries a Unconditional Performance Guarantee on bedrock – an industry first.
By |2016-10-27T19:00:46+11:00February 25th, 2016|News|0 Comments

Free underpinning – for several clients in the last few years…

Yes you read that correctly!!  Not only is Deep Pinning the best underpinning system available, the geotechnical information we gather into the soil moisture levels on the surface AND at depth, regularly locates the cause of the footing problem.  In recent times insurance companies have been approving repairs under their policy due in particular to the confidence in which we can pinpoint the problem area and the source.  In cases of leaking buried pipes, driving the ‘pins through the soil profile can detect differences in softness due to moisture penetration.  By comparing the installation resistance between different areas it is possible to effectively locating the ‘epicenter’ of the pipe failure.

A recent project in Sandy Bay, Hobart had some new paving laid around the sides and rear of the property some years ago.  The plumber unfortunately did not seal the outlet pipe for a storm-water pit serving 3 agricultural drains and a garage roof downpipe so seepage could escape unseen from between the pipe and the rough cut of the base of the hole in the pit, flowing freely into the downstream pipework trenches.  As the pipes passed quite near to the side the house, over time the moisture saturated the heavy clays down to the founding depth of the generous footings.  As the pavers were laid on a concrete slab, no surface rutting due to the moisture softening was evident although rising damp in the brickwork was an important clue.  Eventually the house settled along this side and starting tugging on the abutting external and internal walls.  When the first jacking underpin hole was created, water was flowing into the excavation like we had burst a mains water pipe – it had clearly been collecting in the surrounding clays for some time.

An alternative underpinning company had previously attempted to raise the footings, however, as they had no way of assessing the problem and the scope of the situation, were not able to treat the cause.  Subsequently, the problem remained even though there was a false impression the symptoms had been treated.   This is one of many examples where “Deep Pinning” and its all important processes, demonstrates its ‘holistic engineering’ approach to underpinning – finding the intrinsic cause of the problem is equally (if not more) important than treating the symptoms.  In this example the clients were just as relieved the source of the settlement was addressed (their mood somewhat helped by the repairs being fully covered by insurance) and not at all worried about the cracking itself, as it should be.

By |2016-10-27T19:00:46+11:00February 25th, 2016|News|0 Comments

The Deep Pinning philosophy.

“Welcome to our website.  If you suspect your home needs some underpinning, please contact us for a no-obligation consultation.  There may be existing factors such as trees that are too close to a footing, ground subsidence due to nearby retaining wall failure etc. which can be dealt with simply and therefore underpinning is not required.  Never agree to underpinning until a full assessment has been carried out by an experienced geotechnical engineer – often salesmen do not understand the whole structural system by which structures and the ground profile interact.  Underpinning should be considered the last resort – not the knee-jerk response.  In some cases, underpinning can make the situation worse as a stable reference is created which exaggerates the ongoing movement in the rest of the dwelling.  If a contractor suggests that underpinning is necessary without asking you detailed questions about your property and it’s history, then their solution may be unjustified, ineffective and a waste of your hard-earned money.  Often when a problem appears in a previously stable home, there is a defined event, such as a leaking water supply or sewer/stormwater pipe, which has triggered the footing movement.  If fixed quickly, the foundation conditions should return to their previously stable state – no underpinning is normally required.

I offer a wholistic approach to footing repairs, putting myself in the ‘footings’ of the house and trying to determine what has caused the change in behaviour.  Most people are surprised to learn that most homes I assess do not require underpinning either because the original trigger which lead to the movement has been repaired in the past or that something as simple as blocked gutters, garden taps left dripping or rainfall run-off from a neighbours’ driveway is creating the foundation imbalance.  We always endeavour to treat the cause of the problem AND the symptoms.

Thank you for visiting the site.  I hope the information I have gleamed from over 20 years of specialised experience as a site-based Geotechnical Engineer helps you decide on the best possible solution.  Be assured that being bound by the Institution of Engineers Australia’s code of ethics, advice I provide is genuine, professional and the most cost effective in the long term.

I am very proud of the underpinning system I have developed over many years and believe it has revolutionised the field of underpinning for the better – I look forward to helping you if required in the future.”


Michael O’Halloran  BE (UTAS) PEng. HIA Member.

Owner, The Underpinning Engineers. Inventor of Deep Pinning.

By |2016-10-27T19:00:46+11:00February 25th, 2016|News|0 Comments