Chemical soil termite barrier
A chemical soil termite barrier is a termiticide-treated soil zone (bifenthrin, fipronil) forming the chemical route under AS 3660.1 vs a physical barrier.
Ask Chalkline about this →A chemical soil termite barrier is a termiticide-treated soil zone around the building perimeter and under slab penetrations, forming the chemical route to AS 3660.1 compliance as opposed to a physical route (stainless mesh, graded stone, treated sheet). The active in the soil is a termiticide, typically fipronil (non-repellent) or bifenthrin (repellent synthetic pyrethroid).
What it is
A licensed pest tech applies a soil-stable termiticide formulation to:
- The perimeter trench around the slab edge (post-pour) or to the slab-prep blanket (pre-pour).
- Under slab penetrations (plumbing, conduit, columns) before pour.
- Around construction joints in multi-pour slabs.
The treated soil forms a chemical-active zone that termites either avoid (repellent) or transit unaware while picking up a lethal dose (non-repellent).
Chemical vs physical barrier families
AS 3660.1 recognises three barrier families. Builders pick one (or pair two for redundancy):
| Family | Examples | How it works |
|---|---|---|
| Chemical soil | Bifenthrin, fipronil, imidacloprid in soil | Termites contact or transit the treated zone |
| Physical | Termimesh, Granitgard, reinforced slab | Mechanical exclusion, no chemistry |
| Treated-sheet | Kordon, HomeGuard | Physical sheet + embedded chemical |
Chemical is typically cheapest at install. Physical lasts the life of the building with no recharge. Treated-sheet combines both at a price premium.
Service life
| Active | Soil-stable life |
|---|---|
| Bifenthrin | ~10 years |
| Fipronil | ~8 years |
| Imidacloprid | ~5-8 years |
After service-life expiry the owner faces three choices:
- Recharge via pre-installed reticulation pipework.
- Re-trench and re-treat (disruptive, landscaping-blocked).
- Switch to physical (major work).
The pre-installed reticulation system is the deciding factor in whether recharge is cheap or expensive at year 8-10.
For a builder
- Coordinate the pest tech with the slab program. Pre-pour blanket goes in before reinforcement; perimeter trench after pour.
- Document active + concentration + applicator + date. Required for warranty and recharge scheduling.
- Pair with reticulation unless the owner is OK paying for re-trench at year 8-10.
- Brief the owner: the chemical zone is not a barrier they can see. Stick to the inspection cycle; the system has finite life.
- For non-repellent: explain the transfer effect. Mud tubes may appear during the colony-kill window; that’s the system working.
Category: Termite management.
Related
See also
Last updated: 2026-05-29. Verified: 2026-05-29. Quarterly review for currency.