How big a gap do termites need to get through concrete? Read a study on how a concrete slab can be used as a termite barrier. It's food for thought for anyone building a home on a concrete slab. A few tweaks and you can have the termite protection permanently built into your home!Read More
This post explains and shows why physical termite barriers fail, they're all designed to work. So why do things go wrong?Read More
Concrete slabs form an important part of termite management nowadays, with slabs being used as termite barriers as they are considered termite resistant (if poured in accord with AS2870) the only potential problem is where pipes or other materials penetrate the slab. Whilst things such as plumbing and electrical conduits are easy to locate and treat, sometimes there are building practices that inadvertently create penetrations through the slab, such as when putting in temporary formwork during construction of slabs, as demonstrated by these photos.
Reo bar used to peg out the step down in wet areas of this slab were left in place, creating a termite highway!
It is important to check all potential entry points by ensuring no penetrations through the slab are left untreated.
Physical termite barriers, like all types of termite barriers, are designed to prevent termites getting into a building undetected. A physical barrier does this by preventing them being able to access the inside of the building and forcing them out. To that end, the barrier may be connected to either a concrete slab, or it comes out to a visual inspection zone, as is illustrated in these pictures.
The pivotal thing about visual inspection zones is that they need to be clear of obstructions and easy to see. The Australian Standard (AS3660.1) as well as all barrier manufacturers recommend that a clearance of 75mm be available between finished ground height and the barrier.
So if your home or a home that you are considering buying has a physical barrier, then you may want to check that there is sufficient clearance around the perimeter. Making sure that there isn't anything covering it up, as the barrier cannot work unless it has been installed correctly, irrespective of the type of barrier used.
A physical barrier running into a step, for this barrier to work, it needs to be cast into the concrete step. It's important to check all these details. This barrier was not cast in, potentially allowing termites to get in undetected.