Patio Slab and Termite Regulations

[spartan]

Hi Guys,

I'm looking for some information on the regulations for termite barriers and such.

I'm in the process of building a new patio which is attached to the existing house. The area of the patio is about 90sqm.

The patio is built by a contracting company and they have engaged a private certifier to approve the completed work.

Separate to this work I am having a concrete slab laid. The concrete will be after the completion of the patio - by a licenced concretor.

My question is....am i required to have some form of treatment for my new slab?

If it matters the house is slab on ground and is 20 years old and treated with the old fashion last forever chemicals. The frame is made of cypress.

The new patio is constructed with H3 treated pine and 150 x 150 cypress posts.....

Any advice?

[Ian Smith]

Spartan,
I think you ignore those little buggers at your peril.
I have a house slab that's been down nearly 30 years and, like yours, there's some pretty lethal stuff under it. My house is also steel framed, so I thought I was pretty immune. Didn't stop 'em though. In they came, set up a nest inside a wardrobe and proceded to devour metres of skirting.

Ian

[Pulse]

Hey spartan,

The house slab provides protection if it is monolithic with no construction joints. There should be 75mm exposed all around the perimeter to allow inspections. Termimesh is a good way to join the two slabs. It can be "parged" to the existing slab and the free edge cast into the new slab.

Cheers
Pulse

[silentC]

The regulations are that you have to provide a barrier. They don't go into details about what is to be done, that is up to the builder (you?) as it is the builder who has to provide the warranty.

As Pulse says, you only need a barrier where the new slab butts up any part of your existing building, provided the edges of the slab are exposed by at least 75mm. I'd also recommend Termimesh if it's concrete to concrete or concrete to brick. If it's concrete to anything else, you need to have a look at what you are trying to do because you might be inviting trouble.

If you go the Termimesh route, get your local contractor to come around for a look before you do anything because they are ultimately responsible in terms of warranty and they will tell you the best way to do it.

[spartan]

My existing slab doesn't have exposed edges. So I would imagine it will be new slab against brick.

Is Termimesh still an option?

I've been given a rough cost of about $800 for about 20 l/m of an irrigation system.

[spartan]

Just got off the phone from Termimesh, they said not a good option....

[silentC]

Did they say what the issue was? Would the new slab be below or above the termite barrier of the existing slab? What you need is something to stop them coming up between the slab and the old bit.

I used some stuff called granite guard once where I had a slab butting up to the foundation wall about 600mm below floor level in the existing part, but I could have probably used termimesh in the same situation had I known about it then. It wasn't a perfect solution because there was nothing to stop them coming up through the brickwork and then out into the new wall. I had to leave inspection points so that you could see the back of the old house.

Better describe exactly what your setup is, or post some pics.

[spartan]

Camera batteries are on the fritz.....

Looks like the answer may be Kordon, it is about half the price of the irrigation system.

[silentC]

Keep in mind that Kordon is a chemical impregnated material and you can't replenish it. I talked to my building designer about using it and he reckoned that the chemical will break down in time and become ineffective. From the Kordon site:


Based on trial work that has been carried out, Kordon has been extrapolated to last a minimum of 50 years to date by the CSIRO.
This information is supported by 17 years of trial data.

By 'extrapolated', they mean they took an educated guess.

My preference will always be for 'hardware' barriers like Termimesh that don't rely on chemicals.

The problem with reticulated systems is that the EPA has cracked down on chemicals used for pest control to the point where some pest inspectors I have spoken to don't rate them very highly. There's always the chance that they may be banned altogether in the future, so what do you do then?