© Craig MacDonald
Growing up in Scotland, I was used to looking at long rows of houses in a conservation area. The buildings were aesthetically consistent and consequently shared a character, successfully conserving the history of an area through planning and building control.
In stark contrast, take one look at a suburban hillside in Australia today and you will see a patchwork quilt of steel sheet roofing in a range of colours between lush, subtropical flora. Homes in Australia come in all shapes and sizes, and the state of Queensland is no exception: it is home to one of Australia's oldest and most recognisable forms of housing: the Queenslander.
The traditional Queenslander was typically constructed between 1880 and 1920. It's possible that no one alive today has built an authentic Queenslander, although there is no shortage of contemporary attempts to replicate their charm.
When inspecting a Queenslander, good knowledge of construction technology and building pathology will go a long way. But there are particular issues with both the building archetype and the region that require special attention.
When settlers first constructed Queenslanders they were typically on leasehold land, so the ability to take their home with them was important. This is a characteristic that endures today. Owning a Queenslander now means you don't have to part with it, but can simply have it moved to a new location. The costs involved are surprisingly reasonable.
For surveyors – or to use the accepted Australian terminology, building inspectors – this means it's important to determine whether the house has previously been relocated, as well as the condition and adequacy of the stumps, whether they were installed correctly and when; it's possible they are not the originals.
Inspectors must also consider the prevailing climate. When Queensland goes through its inevitable extended dry periods, the soil dries, causing it to shrink and the ground to move. Cracks can then appear in brick houses, but typically won't affect Queenslanders unless brick upstands have been added between stumps to create a secure store underneath. So as a general rule, Queenslanders are much better at withstanding ground movement and less prone to damage as a result.
'When inspecting a Queenslander, good knowledge of construction technology and building pathology will go a long way'
Another important consideration when surveying Queenslanders is termites. Termites are not fond of natural light and, if exposed to it or to the open air, they will dehydrate and die. They therefore build mud tunnels over hard objects rather than emerge.
These tubes, or galleries, are made up of partly digested timber and excreted mud, and are moist if in active use. Termites keep their colony nest and galleries at 25–35C and high humidity, living in constant darkness except during the annual summer swarms when winged reproductive termites take flight.
Given the timber-frame construction, it is essential for a professional pest controller to adhere to the requirements for inspections and reports set out in AS 3660.2: 2017 Termite management in and around existing buildings and structures. This will help correctly identify the species found in a property. Some species of termites will not attack dry-seasoned timbers in a building, while others can be highly destructive in a short amount of time.
All types of home in built-up urban areas are at risk, especially if there is a typical termite habitat nearby, such as a well-established gum tree within a 100m radius – a common sight in suburbia. Termite colony development is also encouraged by automatic watering systems, landscaping, maintenance and inappropriate design that allows hidden entry into a building.
If the presence of termites is identified, they are not to be disturbed. Should they be shaken up, they will often abandon the area and move on to cause damage in other parts of the building.
In the early days of Queenslander construction, settlers attempted to deal with termites using hot tar, castor oil and arsenic – often without much success. In a few cases, therefore, it may be possible to identify soil that has been contaminated. Today, an approved chemical soil treatment is used around the perimeter and subfloor of a building to eradicate termites trying to gain entry, and is typically renewed annually.
In limited circumstances, particularly in areas where there is live termite activity, bait stations are installed and monitored. This method relies heavily on the insect finding and consuming sufficient bait and returning to the nest without entering the property, however.
Ant-capping on the top of the stumps – a metal plate which creates an overhang or drip – can restrict the access of termites into the building as well, but they don't render it entirely pest-proof. They act as a deterrent because termites don't favour creating their galleries upside down, and if they are successful they become easier to identify. When the building is affected by wood rot, a Queenslander can make the ideal environment for termites to thrive.
Generally speaking then, termite risk reduction measures include improving subfloor ventilation, removal of timber in contact with the soil, and improving access areas for inspection.
For any residential pre-purchase building inspection in Australia, the surveyor or building inspector must adhere to the relevant Australian Standards including AS 4349.-1 Pre-purchase inspections and AS 4349.3 Timber pest inspections, and if the state requires, hold the relevant licence to undertake each of these.
Craig MacDonald MRICS is project and technical services manager at Cromwell Property Group
Contact Craig: Email
Related competencies include: Building pathology, Construction technology and environmental services, Inspection