Renovation Jobs That Void Termite Protection

A termite barrier only works while two things stay true: the treated or sealed zone is unbroken, and the inspection zone around the house stays visible. Several ordinary renovation and landscaping jobs break one of them without anyone noticing. Each question below is answered first, then I explain why it matters and what to do instead.

If you are about to open up walls or floors, read why to book an inspection before you renovate as well. This page is about what the work does to the protection outside and under the house.

Does renovating void my termite warranty?

Not automatically, but it limits it. The 8-year warranty on a chemical barrier and the 50-year warranty on a pre-construction physical barrier both depend on annual inspections, and work that disturbs the barrier isn't covered until I've checked and restored that section. Tell me before the work starts, not after.

A barrier that has been dug through or built over is no longer doing its job, whatever the paperwork says. A disturbed section of treated soil has to be restored before a new surface seals it in. That is quick beforehand and slow and costly afterwards. For how the annual inspection and the 8-year mark fit together, see how often a termite barrier needs renewing.

Can I tile or render over the slab edge?

No. Where the slab edge is part of the termite protection, AS 3660.1 needs it exposed for at least 75mm above the finished ground, landscaping or paving, and it can't be rendered, tiled, clad or covered. That visible edge is where termite mud tubes show up.

Subterranean termites travel in mud tubes to stay out of the open air. On a bare slab edge the tube is visible to anyone looking. Behind tile or render it is hidden, and the first sign can be damage. The standard makes no allowance for tiling down to the edge with a gap, so finish tiles and render above the exposed strip, not over it. If a tiler has already covered it, call me before you try to fix it yourself.

You can read more about why the edge has to stay visible in the 75mm inspection zone explained.

Can paving or concrete go right up to the house?

Not up to the slab edge. Paving or concrete laid flush against or over the edge fills the 75mm inspection zone permanently. Keep the finished surface at least 75mm below the top of the slab, so at least 75mm of edge stays showing, and at least 75mm below any weep holes.

New paving should also fall away from the house, because water that drains towards the wall adds moisture where termites look for it. The digging and levelling before a pour can disturb treated soil next to the house, and the product label is clear that a disturbed treated zone has to be restored. That means treating it before the concrete goes down, not after.

If you are redoing a path or driveway, ask for the slab edge to be left exposed along the full run, not just where it is easy.

Can I build garden beds, soil or mulch against the walls?

No. Soil or mulch built up against a wall buries the 75mm inspection zone, and termites can build mud tubes up the hidden slab face for years without anyone seeing them. Keep the slab edge exposed to at least 75mm, keep garden levels at least 75mm below the weep holes, and keep mulch off the wall.

Mulch attracts termites, and once they are at the structure they go straight to the joists and bearers. Coptotermes, the termite I find most often in Sydney homes, reaches timber through the soil, so a garden bed that hides the edge also hides the first sign of it. Pull mulch and soil back from the wall so the edge stays in view.

Can I attach a new deck, pergola or steps to the house?

Yes, as long as it doesn't hide or bridge the protection. AS 3660.1 says decks, steps, verandahs, porches and similar attachments should sit at least 25mm clear of the house so the inspection zone can be seen. If a deck has to butt up against the house, the termite system has to be extended to cover it.

Posts and stumps need a 75mm inspection zone, and timber posts set in the ground have to be H5 treated or a naturally termite-resistant timber. If the house itself has a raised timber floor, the standard asks for at least 400mm of clearance underneath so it can be inspected. Timber lying on the soil attracts termites, which is why I remove old sleepers sitting on the ground near a house. Digging post holes close to the house can also disturb treated soil, so plan the footings clear of the wall and tell me before they are dug.

Can I extend or add on without breaking the existing barrier?

Not without planning it. An extension is new building work, so it needs its own termite protection, and the joint between the new and old work is the weak point. The standard itself warns that it may not give adequate solutions for an extension joined to an existing house, so get the termite side planned before the slab or floor goes in.

AS 3660.1 recommends the designer, the builder, the termite specialist and the owner work this out together at the design stage. Where full protection can't be achieved at the join, the limits should be written down and given to the owner, along with more frequent inspections.

I install TermSeal and Green Zone barriers, and reticulation systems, to AS 3660.1. A physical barrier like TermSeal goes in before the slab is poured and can't be fitted afterwards, which is why the termite side has to be in the plans. For what the standard asks of new work, see AS 3660.1 explained for new construction and what NCC Part 3.4 requires of builders. If the extension is being built now, see pre-construction termite barriers. The 50-year warranty on a physical barrier stays conditional on annual inspections. Ask me for a quote once you have the plans.

Can I run new pipes or conduits through the slab or walls?

Only with the penetration protected. On new work every pipe through a slab needs its own termite protection, such as a collar, fitted before the pour. A pipe cut through an existing slab later has none of that, so tell me before the plumber or electrician cuts anything.

Every hole through a slab or wall is a path past the barrier if it is left open. For a new penetration I treat the soil around it, usually by drilling and injecting termiticide, and check it at the next inspection. The exact method depends on where it is, so I would look at it before saying.

Can cladding or render go down to the ground?

Not if it covers the slab edge. Render, cladding or any other covering over the exposed edge hides the inspection zone, so keep the bottom of cladding and render above the 75mm strip, and check the levels again once the garden is done.

Cladding or render taken down to ground level hides the zone an inspection relies on, so a termite tube behind it is never seen. A landscaper raising the ground after the cladding is up can do the same thing from the other direction.

Can I change the drainage or let overflow pipes drip next to the house?

No. Water should drain away from the house, and finished ground sloping towards it is a high risk. Run air-conditioner condensate and hot-water overflow pipes into the garden well clear of the wall, because constant moisture next to a slab or subfloor invites termites.

Moisture is the main condition termites look for. A condensate pipe dripping against a wall, a leaking gutter or a garden that drains towards the house all keep that moisture where it does the damage. The fix is often small, such as a hose clipped onto the pipe and run into the garden clear of the wall. If you are changing the levels or the drainage, check which way the water now goes.

Can I build a retaining wall or add fill against the house?

Not against the wall. Fill or a retaining wall built against the house buries the slab edge and the 75mm inspection zone, holds water against the wall, and disturbs treated soil, which then has to be restored. Keep the wall clear of the house, with room to see the edge and a drain behind it.

Timber sleepers make this worse, because timber on the ground attracts termites. If the ground has to be raised, talk to me first about how the edge stays visible.

What about a reticulation system's access points?

Leave them accessible. A reticulation system lets me top up the treated zone from outside the building, which only works if the filling points stay uncovered and can be found. Don't pave, tile or garden over them.

The filling points are listed on your certificate of installation, along with how much termiticide each one takes, and I'll show you where they are. A soil barrier without reticulation can still be re-treated once it has been built over, but it means drilling through the paving or slab and injecting, which is slower and costs more than topping up a reticulation system.

What should I tell my pest manager before the work starts?

Tell them what you are doing, where, and when the surfaces go down, ideally before you accept a quote for the work. Anything that touches the slab edge, the soil or a penetration needs checking before it is sealed in, because afterwards it can't be seen. Then keep the annual inspection going, because the warranty depends on it.

If a builder or landscaper is doing the work, ask them to keep the slab edge exposed and to tell you before they dig near the foundation. Book a check once the work is finished to confirm nothing has been bridged.

If you are planning any of these jobs, call me on 0405 790 927 before the work starts, or book a termite inspection. I'll look at the house and tell you what the job does to the protection.