TERMITE CONTROL BARRIERS IN PORT MACQUARIE
After regular Termite Property Inspections, an additional protection your home can have is a barrier system to impede and discourage the concealed entry of termites into your home. This should be carried out in accordance with Australian Standard AS 3660.2 for existing buildings and AS 3660.1 for buildings under construction.
The initial paragraph in the foreword to AS 3660.1 states, that;
“The purpose of termite control barriers is to deter concealed entry by termites into a building, above the termite barrier. Termites can build around barriers but their workings or evidence thereof are then in the open where they may be detected more readily during regular inspections.”
Termite Control Barriers on their own do not protect a building from Termite attack. They are like an Ant Cap on a brick pier, they are are a deterent for concealed entry and an aid in the detection of Termites during a regular Termite Property Inspection.
With new homes built on concrete slabs, the slab may form part of a termite barrier system if it is constructed to AS 2870.1. However, the termites can still come around the outside edge of the slab. AS 3660.1 specifies the requirements for perimeter protection. The Standard also stresses the necessity for regular (minimum every 12 months), competent inspection of termite control barriers.
There is some industry refusal to use the word Barrier. This is because the word barrier can be defined as “obstructing passage, maintaining separation or preventing progress”. Termites can and do get through what was known as barriers. Therefore the Courts are finding that these treated areas are not in fact barriers because termites find ways to still enter a dwelling surrounded by barrier. This fact is noted in AS 3660.2. The more accurate term therefore is Treated Zone. The problem is not the failure of the Treated Zone, however Termites do and always will, sometimes bridge the zone or access an area where something else has bridged the zone.
TERMITE CONTROL BARRIERS
Two types of barriers/ zones are used, chemical and physical, often in combination.
Metal shields, stainless steel mesh or granite chip barriers can all be used to deter the concealed entry of termites into buildings. Termite shields (caps and strip shields) are installed on all substructures (isolated piers or posts and along walls, etc) to provide a continuous barrier. Continuous sheets of fine stainless steel mesh can be installed under buildings during concrete slab construction. In certain situations, it may be adapted for service openings or wall cavities in existing structures.
Graded stone barriers are made up of a thick layer of small granite chips graded to a size and shape that cannot be transported by the termites and spaces between the particles are too small for termites to get through. Such stone barriers can be installed underneath a concrete slab or beneath a suspended floor. Such barriers are yet to be developed for tropical northern areas, which are inhabited by large termites (Mastotermes darwiniensis) that can make their way through the standard granite chip barrier. Physical barrier systems should be installed by an accredited installer and then inspected as part of any Property Termite Inspection.
Chemicals that are used to kill termites are called termiticides. Termiticides have differing modes of action, and several methods are used to apply them. For many new buildings, creation of a termiticide-treated layer of soil surrounding and under the building form an integrated zone together with or as part of the physical methods described above. The termiticide is applied to the soil under the slab and around the footings, pipes, conduits and other structures of the house during construction to create a vertical zone. Further loosened soil around the perimeter of the house, including around all pipes and service facilities, is treated during and after construction to from a horizontal zone. Timber intended for use in the construction of houses, outbuildings, fences and other outdoor structures is often treated with chemicals by dipping and pressure or vacuum impregnation. Chemical zone systems should be installed by a licensed pest control operator using termiticides approved by the APVMA.
The termiticide used may repel termites, it may kill those that enter the treated area OR it may be nonrepellant and allow termites to forage through the zone and later kill them, as well it may be taken back to the nest on the bodies of the termites where it kills others of the colony by contact. With currently approved termiticides, an underfloor zone may be effective for 4–10 years and an external zone for 2–8 years, depending on climate, soil conditions and soil disturbance. To successfully complete termite zones for existing buildings, strategic drilling/ cutting through concrete slabs, porches, floors and wall footings may be needed, as well as under-floor treatment. This needs to be carefully worked out by a qualified pest control operator. Reticulation systems (similar to drip irrigation watering systems) may be installed which aids the reapplying of the chemical at regular intervals in the future.
As with physical barriers/zones, repellant chemical zones are are a deterent for concealed entry and an aid in the detection of Termites during a regular Termite Property Inspection.
Termite Terriers Pest Control currently utilises Non-Repellant Chemicals as a part (in some suitable properties) of an overall Termite Management Program in conjunction with Aggregation, Monitoring and Regular Termite Property Inspections.