Core-filled concrete block walls must be treated for termites

There is a Builder’s Myth that core-filled concrete (besser) block walls don’t need termite proofing.

A core-filled block wall is not certifiable unless you have vibrated the fill from the bottom to the top and used a certain quality of concrete. Ask your Certifier - they have the final tick of approval.

Best Practice Termite Proofing:

• You should apply a sheeting or termite-repelling product externally before you backfill.
• The termite management system should be “life of structure” - 50 years.
• If you are only using a steel mesh product, there must be a visual clearance of 75 mm or more, from the soil line to structural timbers.

Desperate calls from Builders

We get too many calls from Builders about how to termite-proof concrete block walls just before the internal timber frames are to be constructed!

If you have not applied termite proofing to the external side of the block wall down to the footings, you’ll need to do something inside.

What to do if you’ve stuffed up!

There are only three options if you have missed the opportunity to apply a termite-proofing product on the outside of the concrete block wall:

1. Dig the backfill out and termite-proof the external face of the block wall.
2. Sheeting product adhered to the wall from slab/footing to the top of the block wall. (You can’t nail through the sheeting material).
3. Termite-proofing coating is to be applied from the slab/footing to the top of the block wall. (You can’t nail through the coating material).

Products we recommend

1. Homeguard TMB Sheet

Homeguard TMB sheet is glued directly to the block wall with a strong 3M adhesive. You cannot nail timber/steel battens through the product to allow wall linings to be placed.

2. Protectacote - Termite proofing coating

If you are looking for a direct application product, then FMC Protectacote is ideal. It requires three applications. Initially, a primer, two top coats are applied by roller or brush. It can also act as a waterproof membrane with a thickness is over 4mm (non-certifiable).

The hoops we need to jump through

Requirements to install a termite management system to NEW construction

The license for an installer is different from Post-Construction (existing structure). They need these additional qualifications and be able to issue appropriate paperwork:

Licenses

• They must be licensed through the QBCC (Queensland Building and Construction Commission) with their Termite Management – Chemical & Termite Management – Physical.
• They need to have their Queensland Health Timber Pest license
• They also need to have the Unit of Competency 42 – Install Physical Termite Management System
• They need to be officially accredited by the manufacturer of the system/product they are installing

Paperwork to gain certification:

• Have a termite system installed to the manufacturer’s instructions by a licensed and accredited installer.
• Form 43 is a document given to the Certifier stating the scope of work and products used.
• A Certificate of Installation (COI) to the Australian Standard AS3660.1 Termite Management Part 1: New Building Work
• A Durable Treatment Label – normally adhered in the electrical meter box

Contact Conquer Termites

If you are stuck with a tricky situation or need some advice, call us now on 1300 417 007