Combine chemical and physical termite barriers to get comprehensive protection
for new constructions

Chemical barrier termite treatments are most often used for termite protection in existing properties. However, they still have a role to play when combined with physical termite barriers in new construction projects.

This is especially the case when the construction design means that physical termite barriers alone may not be sufficient to provide complete termite protection.

However, with new termite management regulations in play in Melbourne, it pays to use professionals who are up to date with the building and pest requirements.

When to use chemical applications for termite protection

Chemical applications sprayed to the soil surface, before pouring a concrete slab used to be a common way to provide protection to new constructions. However, with changes to the various Building Codes and Standards, on it’s own, this is no longer an acceptable way to provide termite protection.

If chemicals are used as the primary method to deliver termite protection to inaccessible areas (eg. Under concrete slabs), after treating the soil, a reticulation system has to be installed before construction, to allow the chemical to be replenished in the soil every few years.

Chemicals are still a good option for treating the soil under buildings on piers or for buildings where the construction design may not allow sole reliance on physical termite barriers.

Chemical soil treatments are commonly used around the perimeter of buildings, but if paths or driveways are to be installed, again, a reticulation needs to be installed before laying the path or driveway.

Chemical soil treatments are still a common way for treating existing homes. Having been built before the requirement to install a reticulation system, such treatments are still allowed and provide excellent protection, with chemical being injected into the soil under paths and driveways through drill holes.

How does termite treated soil provide protection?

Termite treatment chemicals called termiticides are suspended concentrates of insecticides. By adding water to dilute the termiticide, the product can be evenly applied to the soil. Once the suspended particle comes in contact with the soil it bonds with the soil within a matter of days, thus creating a treated zone in the soil.

Although such termite treatments are typically called termite barriers, they are more correctly referred to as a treated zone. This is because they don’t really create a barrier – not one that provides 100% protection from termites – that’s not how they are designed to work. Treated zones are designed to prevent concealed entry to the building. If properly applied, in conjunction with the physical features of the building, the only way for termites to access the building would be to build a mud tube (or move across fallen vegetation) over the top of the treated zone. If they manage to do this, they can be easily spotted during a termite inspection and dealt with.

Types of chemical barriers

There are two types of liquid termiticides; repellent termiticides (older, but cheaper technology) and non-repellent termiticides.

Repellent termiticides do kill termites but they are actually designed to provide a repellent treated zone in the soil that the termites will not enter. This is great when you have a continuous treated zone, but with variations in soil type and the presence of rocks and plant roots, it makes it virtually impossible to ensure an even application. As such, it is possible for termites to find a gap in the repellent barrier and enter the home.

Non-repellent termiticides are the more modern technology and cannot be detected by termites. Termite will enter a treated zone ‘by accident’ and be killed. These chemicals are still susceptible to uneven application, but since termites cannot detect the presence of the chemical, they cannot detect gaps in the treatment either – the chances of termites finding their way through an untreated zone without also hitting a treated zone are tiny.

However, since the repellent termiticides are far cheaper than the non-repellent termiticides, they are commonly chosen in pre-construction applications. When used in conjunction with a reticulation system and integrated with the construction elements and any physical termite barriers, they can still be a valuable tool in a well-designed termite management system.

Depending on the chemical used and soil type, a liquid termiticide treatment should remain effective for between 5 and 10 years.

Termite reticulation systems

Pipe reticulation is basically an irrigation system designed for termiticides. Although there are slight variations between systems, it is essentially a network of inter-connected tubes that have small holes throughout. The system is filled with termiticide by pumping through one or more connection points and the termiticide leaks out through the holes in the pipe work into the soil.

The use of a reticulation system under concrete slabs, paths and driveways is essential to allow the treatment to be re-applied to the soil. It avoids invasive maintenance in future years (digging up paths, drilling holes in concrete) when the soil needs to be re-treated.

Reticulation systems are also a great problem solver for areas where access may be difficult, such as underneath decking.

It is also useful to lay reticulation systems in areas of uncovered soil around the perimeter of the home as well. Although it increases the initial installation cost, it does reduce the cost in future years when re-treatment of the soil is required. Essentially having a reticulation system in place adds value to the home.