Termite protection - new and existing building work

[Theremin]

a chemical soil barrier can be used as an external perimeter barrier. it consists of a a trench treated and backfilled with treated material and covered by 50mm concrete cover strip not less than 300mm wide measured from the external wall of the building - BCA (qld acceptable construction manual 3.1.3.0)

Hi dirtgirl - are you able to clarify whether this is for new or existing building works, or doesn't it matter?

Also, the plot thickens a bit, because I've checked our building plans and they actually specify that a chemical soil barrier must be installed. So, the inspector (a private certifier) will be getting a call first thing tomorrow morning to ask why they won't sign off on the work that has been done in accordance with the plans they approved.

[dirtgirl]

Hi Theremin, That section of the BCA refers to AS3660.1 New building work but AS3660.2 for existing building work section 6.3 refers to AS3660.1 for physical barriers, so it looks like a physical barrier will surfice for both new and existing, bitingmidge's solution for a replenishable system is also BCA compliant, so I guess you have a number of solutions that should satisfy your building inspector, regards M

[dirtgirl]

A full chemical system of termite contol is permitted for underslab protection of penetrations and control joints with a slab edge exposure system permitted for perimeter or a physical barrier like bitingmidge or I proposed if you cannnot easily inspect the perimeter of your slab (75mm clearance etc), BCA Table 3.1.3.1 Queensland variation

[thebuildingsurv]

The existing works should be irrelevant unless you poured new footings. AS 3660.2 is not even referenced in the BCA. The BCA has a qld state variation that does not allow chemical barriers where visual inspection is not possible. So it may be the case the you have less than 400mm clearance and that is the problem. Why dont you ask the certifier to put in writing why it doesnt comply or highlight the sections of the code it doesnt comply with. You need to be more specific.
There must be avenue to modify the regs if major work will be required to rectify it. After all BCA is a performance based document.

[ausdesign]

'morning Theremin. Hopefully your call this morning has resolved your problems. Keep us informed.

Going by your first post I assume the new building works are constructed on a concrete slab.
I've been known to eat humble pie before but put the following:
The (if any) termite protection to the existing dwelling should not come into the equation as far as new reg's are concerned.
If the extension is on a concrete slab then a perimeter spray is allowed if (in Qld - I think the proviso to the BCA was adopted around 2000, 2001) the soil is trenched around the perimeter & is capped by 300mm wide concrete - just saturating the soil around the perimiter is not deemed to comply.
Any penetrations such as vanity basin pipes etc should be 'collared' with an approved termite barrier such as termiguard etc
end of storey.

Maybe for the benefit of readers (myself in particular) you could detail exactly the construction, the events that ensued & the outcome.

[Theremin]

Thanks for all the replies and advice. The current status of the debacle is this. The inspector has agreed to sign off the works provided that:

1. the termite company provides a certificate the the protection complies with AS 3660.1 (not AS 3660.2, which is what they have given me); and

2. I put a 300mm x 50mm strip of concrete around the perimeter of the house.

I've put a call into the termite company and they are looking into it. I expect to hear back from them tomorrow. The concrete strip doesn't worry me much. It's less than 1m3 of concrete, and my trusty GMC mixer should be able to handle that. How long the concrete strip will stay there for is, of course, an interesting question...

[thebuildingsurv]

Sounds like the inspector was just doing his job and the pest controller doesnt know what certificates he should be providing. AS 3660.2 is not appliable to new building work and is not referenced in the BCA. A bit of communication with the inspector and problem solved.

[bugsy]

hi guys,

they is no point installing termi mesh on top of ant capping.
They both are just a psyical barrier.
visit UPMA for pest control questions.