Steel Columns
These have become popular since the mid 60’s as a form of structural support in subfloors, often replacing old timber/concrete stumps. They are now commonly used where houses are raised for under house development and their 75 mm 75 mm design accommodates the wall partition perfectly making them concealed within the lower level developed areas of a structure. These columns are placed in a large drilled out whole within the ground, commonly referred to as a footing, and filled with concrete to strengthen and are attached to the bearers above with coach screws/bolts or via welded connections to steel beams etc.
To provide the best levels of protection to the columns for their longevity, it is critical to prevent any moisture buildup at the base of the columns which will result in corrosion and obviously cause deterioration to the steel column. In order to achieve this, the base of the columns should be well coated with a zinc rich paint and a small mound of mortar should be built up the bottom of the column to ensure no water ponds in this area and is diverted away from the column. Until around the mid 80’s, these columns (usual size 75mm x 75mm x 4.5mm) were supplied as a prime coated material however since that time they have been produced with a light form of galvanising steel columns, known as ‘Durogalv’. There are fully galvanised steel columns that can be obtained, referred to as ‘Supagal’, however they are very rarely used because of their higher price.
It is far from uncommon for us to discover during our inspections, full penetration rust in many steel columns of a prime coated a variety that have been in service for less than 10 years. Their rate of deterioration is obviously affected by the conditions they are subjected to and the lack of drainage and ponding water at the base of the columns has a devastating effect on prime coated steel columns. Prime coated are still commonly used, despite the fact they have a poor longevity and begin corroding almost immediately when in situ. Based on our findings, whether or not they should be even allowed within residential construction, is highly questionable.
In severe cases, the rust penetrates through the steel thickness but this cannot be detected without chipping away at the rust with a sharp tool, unless of course it is visibly obvious during our non-invasive inspections. Where any steel columns have been identified at an address which are showing signs of corrosion of a more significant nature, you should immediately arrange for a complete inspection of all steel columns with the implementation of invasive inspection techniques, as this is the only way to determine the actual levels of corrosion within the columns. These isolated pier footings perform major structural roles for a property and no complacency whatsoever should be taken with the need to regularly inspect the columns and maintain them consistently throughout their life to ensure the integrity of the structure is at its best. The advice of a Registered Professional Engineer of Queensland must also be immediately sought, as this kind of consultant and professional is the only one deemed capable of providing you with advice you can rely on in relation to structural matters for a property.







All too often during our inspections we identify areas which are conducive to the collection of retained ground moisture near a structure. Elevated moisture levels are known to provide conditions favourable to Timber Pest activity, particularly termites, and it is vital that every effort be made to avoid these risks. The most common causes of retained ground moisture are inadequate surface water drainage, downpipes not connected to drainage outlets, no gutters in place for roofing areas, outlet pipes for air conditioners, relief and overflow valves for hot water cylinders, corroding and join leakages of gutters and downpipes, defective or incomplete flashing and plumbing for rainwater tanks leaking. These are all issues which can be, and should be rectified, if they are in existence at a property.







