Soil treatment

Termite soil treatments

Termite soil treatments are perhaps the traditional way to protect existing buildings from termites. Insecticide (termiticide) is applied to the soil around the exterior of the building down to the depth of the footings. In buildings with a sub-floor termiticide should also be applied to soil around the piers and any other sub-floor walls.

Soil is dug up to create a trench and then termiticide is mixed with the soil as it is replaced back in the trench. When the building is surround by concrete, pavers or other solid surface this creates a problem. The recommended best practice is it cut the concrete or lift the pavers so a trench can be dug and the termiticide applied correctly. Sometimes homeowners don’t want to do this, so the termiticide is applied by drilling holes and injecting the termiticide underneath. Although this generally works well, if can never be a comprehensive as digging a trench as you cannot tell what is under the concrete and therefore even distribution cannot be guaranteed.

If the soil is heavy clay or stony, it will need to be replaced with a sandy loam before applying the termiticide.

There are two types of termiticide, repellent and non-repellent termiticides.

Repellent termiticides

Repellent termiticides are pyrethroids. These older style insecticides do kill termites when the termites contact the insecticide, but when applied in the soil, termites approaching the treated zone are repellent and so aren’t actually killed. When applied correctly these repellent termiticides can provide an excellent treated zone. However, if there is some gap in the treated area (which can happen when injecting through concrete), termites can potentially find this untreated area to find their way into the home.

Non-repellent termiticides

There are a number of different non-repellent termiticides, which are all newer types of insecticide. When applied to the soil, termites cannot detect the insecticide and so when the content treated soil, they die. As they cannot be detected, termites are not able to seek out any untreated gaps in a treatment and so the chances of them getting through to the building without contacting treated soil, is very small indeed!

How long do termite soil treatments last?

The length of time that a termite soil treatment last will depend on the chemical used, the soil type and the location (temperature and rainfall have an impact). However, typically all termite soil treatments should last at least 5 years. However, as with all termite treatments, annual termite inspections are a must to maintain any warranties.

What happens when there is excessive rainfall or flooding?

Soil treatments are designed to handle normal amounts of rainfall, but when there is flooding not only is there the danger that some of the treatment will be washed away, but there is the likelihood that soil may be brought in and deposited on top of the treatment. Check out our article on flooding and termite treatments.


For more articles on termite products and techniques.

More detailed information about termites and termite treatments.