Thread: termite resistant timbers

Wandoo is definately NOT termite resistant. As for the others i dont know.

Box is not termite resistent,I am not sure of the other.
Cyprus pine is termits resitent but prone to rot out in contact with wet earth.
Maybe a rethink on the project is called for.
Rowley

Cheers lads,
Glad I asked the question. I thought ants only got into the guts of wandoo and didn't touch the rest. Fingers crossed for lemonscented...

Wandoo is rated by the CSIRO as class 1 for termite resistance which is the best there is.
See here
Forest Products Commission: Plantations: Species information: Arid: Wandoo

That means expect 25 years+ from a quality piece of mature dry well maintained timber.

I too have seen many pieces of Wandoo attacked by termites but the reason the termites eventually get into it is, like all timber, if it left exposed it will eventually crack and as it is very dense any water that enters these cracks takes a long time to dry out. The termites will track the damp cracks and eventually take it out. If it's solid and well maintained it's generally pretty good.

Eucalyptus camaldulensis is the same, a good quality piece of this timber has the same termite resistance class as wandoo.

BTW that website lists the durability for a whole bunch of other trees.

Sorry I can't help out with ya western timbers, but know a whack of 'em over here

Originally Posted by comgreserv

Cheers lads,
Glad I asked the question. I thought ants only got into the guts of wandoo and didn't touch the rest. Fingers crossed for lemonscented...

Darren

Sorry to be the bearer of bad tidings. Lemon Scented Gum is corymbia citriodorus and is similar to spotted gum (C. maculata). In fact in Queensland it is sold as spotted gum.

The timber is OK outside, but not in the ground. So if you were building a stockyard for example, it could be used for the rails but not the posts as it is not resistant to termites.

Regards
Paul

Ah bugger! Looks like i'll have to revisit my choice of timbers. Had thought lemon scented would be ok cos the ants never get into any firewood or logs I have lying around. Perhaps they are spoilt for choice. lol

Originally Posted by comgreserv

Ah bugger! Looks like i'll have to revisit my choice of timbers. Had thought lemon scented would be ok cos the ants never get into any firewood or logs I have lying around. Perhaps they are spoilt for choice. lol

There are many species of termites, but they don't all eat the same timbers. So on occasions I have seen white ants climb over a pile of radiata to get to hardwood leaving the radiata untouched and on other occasions the exact opposite.

There are only a few timbers that all white ants attack.

I expect that there were no lemon scented gum eating white ants around. Ironbark, turpentine, white mahogany and cypress pine are resistant timber, but the latter is not good on the ground like the others as Rowley has already pointed out.

Regards
Paul

Originally Posted by Rowley

Box is not termite resistent,I am not sure of the other.
Cyprus pine is termits resitent but prone to rot out in contact with wet earth.
Maybe a rethink on the project is called for.
Rowley

Unfortunately Box covers a number of varieties. Some are euacalypts, some are tristanias, but even in the eucalypts there is some variance between classes 1 & 2.

My own experience of white and grey box, which are nominally class 1 ( I have no idea which is which and to compound the problem they hybridise too. I was told by one person in response to the "what have I got question?" that you have to take them back to the lab for identification.) is that they are attacked in the end.

As Bobl said, if you get good solid wood it may be ok, but if you are just squaring logs and including heart they will be attacked.

Regards
Paul

dont know why your to worried about it for the rotting an turmite eaten wood should help to make a great little bio enviroment I d be ready to replace them every couple of years and change the pattern I have a soft spot for a good le potager en parterre so what your doing is fantastic.

You could try treating with timbor or some of the other treatments available. Timbor is basically Borax and Ethylene glycol and virtually eliminates the timber as a food source for the termites. There are other treatments which would be safe for use available too, some of which are promoted for exterior use. This is the road I would be looking at get some thing which is fairly termite resistant then treat it with one of these products to ensure its longevity.

The borax based products also help to prevent/treat rot in the timber.

Somebody said Red Cedar posts are resistant, and possibly Turpentine, but I remember reading somewhere that NO timber was TOTALLY resistant to termites. Also, I don't know if it's old wive's tales or not, but someone said that if you absolutely cover the area all around with sugar cane mulch, the termites don't eat any wooden logs or furniture sitting on it. I do know that the seepage from the mulch restricts the movement of soil nematodes (microscopic eel-worms) which burrow into the roots of plants, so I'm not surprised that it MIGHT repel termites (to some extent anyway).


Yes, the Timbor, or other borax products might be the way to go. Telegraph poles have that sort of treatment. The only other way is to use a soil barrier, similar to the perimeter treatment of a house to prevent termite entry, but you've got to reapply that every 5-10 years. Two effective chemicals are: Chlorpyrifos ('Lorsban' 'Dursban'), which will give you 5-10 years protection if not improperly applied, or degraded, While Bifenthrin will give you about 10-12 years, if you're lucky. The old Organo-Chlorines, like Chlordane, Dieldrin, Heptachlor, DDT, etc, were taken off the market some years ago for termites:

(from the Aust Gov't Dep't of Health & Aging)
What chemicals are used as termiticides?


For many years, the prevention and treatment of termites relied heavily on the use of the so- called organochlorine insecticides, such as dieldrin, chlordane and heptachlor (known collectively as cyclodienes, because of their particular chemical structure). These chemicals had some advantages in that they provided 20 to 30 years of protection against termites because of their chemical stability, were extremely effective Australia-wide, and had no immediate adverse health effects at the levels of exposure arising from the approved use. However, these chemicals were largely withdrawn from use in Australia from 1995 because of concerns about their environmental persistence, their tendency to accumulate in the fat of animals and humans, and the potential for them to exhibit toxic effects as their levels built up in the environment through continued use.

The elimination of these chemicals has presented a number of challenges because the replacement chemicals do not provide such long-term protection. The need for more regular applications of the newer, less-persistent chemicals means that there is an increased chance that both householders and the pest control operators will be more frequently exposed to the chemicals.

In recent years there has therefore been much research into chemicals that have suitable persistence, low mammalian toxicity and minimal environmental effects. However, integrated approaches using physical and chemical methods have proved the most successful for prevention or treatment of termite damage.

A number of chemicals are currently approved in Australia as active constituents for use in termite control products. Separate inserts to this brochure outline some basic hazard information about each of the chemicals. For greater effectiveness, two different chemicals may be used in combination.

In the formulated products that are available for termite control, these active chemicals may be mixed with solvents, emulsifying agents or other components to aid application. These formulated products are sold under brand names but the chemical/generic name of the active constituent should always be shown on the label.
Here are 2 termite chemical examples:
CHLORPYRIFOS:
Description and mode of action
Chlorpyrifos is an organophosphate insecticide that has widespread agricultural uses. It is also found in a number of insecticide products that are used in or around homes and gardens, including use as a termiticide. It has a mild mercaptan (sulphurous) odour, sometimes noticeable after treatment of buildings.

Like other organophosphate insecticides, chlorpyrifos kills insects by interfering with the activity of an enzyme (acetylcholinesterase) in the nervous system. This interference causes an increase in levels of the nerve transmitter chemical, acetylcholine, leading to over- stimulation of the nervous system and rapid twitching and paralysis of muscles.


Toxicity

In mammals, the main signs of organophosphate poisoning are increased swallowing, excessive saliva, rapid breathing, pinpoint pupils, loss of coordination, excitement, twitching and rapid contractions of the neck and jowl muscles, coarse generalised body tremors, secretion of tears, urination, defecation, depression, prostration, convulsions, respiratory failure and death. The severity of signs increases with the amount of exposure, but there is an effective antidotal treatment for chlorpyrifos poisoning. Regardless of the route of exposure (oral, dermal or inhalation), the toxic effects of chlorpyrifos are similar.

In laboratory animals, ingested chlorpyrifos is rapidly absorbed from the gastrointestinal tract, but does not remain for long periods in the tissues or organs. It is broken down into other chemicals and excreted relatively quickly from the body, mostly in urine. Inhaled chlorpyrifos is also absorbed but relatively little is absorbed through skin. Chlorpyrifos is a very slight eye and skin irritant but does not cause allergic reactions when applied on the skin (skin sensitisation).

Long-term exposure to low concentrations of chlorpyrifos in the diet was without serious consequences in animal studies, although high concentrations caused similar symptoms to those listed above after single high doses. Both chlopyrifos and its main metabolite gave negative results in a range of genotoxicity tests (that is, tests to assess its potential to damage the genetic material of cells and cause mutations or cancer). Similarly, exposure to chlorpyrifos did not cause cancer, reproductive problems or birth defects in experimental animals.

The possibility of chronic neurological effects after repeated exposures to low levels of organophosphate insecticides has been investigated. Health studies in workers producing and packaging chlorpyrifos products have not shown any differences in the levels of illness or diseases compared with a matched control group not exposed to chlorpyrifos.


Air monitoring studies

Air monitoring studies have shown that if adequate ventilation is used, the concentration of termiticides in buildings after the initial spraying period is very low. For example, in 1992 the WorkCover Authority of New South Wales monitored chlorpyrifos concentrations in the air of seven Sydney houses that had been sprayed in the under-floor area (the treatment procedure most likely to cause the highest concentrations of the termiticide). Average chlorpyrifos concentrations in the houses did not exceed 1 microgram per cubic metre (µg/m³). Breathing air at this concentration is calculated to give an exposure that is approximately 200-fold less than the lowest dose of chlorpyrifos that causes significant reduction in plasma cholinesterase activity in humans (the most sensitive marker of exposure).


Poisons scheduling in Australia

Chlorpyrifos products with high concentrations of the active ingredient are listed in schedule 6 of the Standard for the Uniform Scheduling of Drugs and Poisons (SUSDP). Termiticide treatments around the home are restricted to licensed pest-control operators who have been trained in the handling and use of these products. A schedule 5 classification exists for preparations containing 5% or less of chlorpyrifos, controlled release granular preparations containing 10% or less, and for microencapsulated chlorpyrifos when present at 20% or less in aqueous preparations. Potting or soil mixtures containing 100 g/m3 or less are exempt from scheduling.


Ecological and environmental effects

Chlorpyrifos does not dissolve easily in water. It is strongly adsorbed by most soils and is relatively immobile in the soil. The half-life of chlorpyrifos in the soil has been shown to range from 11 to 141 days depending on the soil type; it is thus considered to be moderately persistent. Chlorpyrifos was least persistent in soils with high pH values. Soil micro- organisms break down chlorpyrifos. Chlorpyrifos is hydrolysed at a moderate rate. Based on data from available studies, chlorpyrifos is unlikely to leach into ground water in measurable quantities under most typical use scenarios.

Chlorpyrifos is moderately to very highly toxic to birds and bees when exposed to direct treatment. Terrestrial non-food application of chlorpyrifos to sites such as turf represents an acute hazard to birds. Run-off from such applications could be hazardous to fish and aquatic invertebrates, as chlorpyrifos is highly toxic to aquatic organisms. Various uses of chlorpyrifos may pose a risk to small birds and small mammals

BIFENTHRIN:
Description and mode of action
Bifenthrin is a synthetic pyrethroid insecticide with a range of agricultural uses. It is also used to form a barrier to repel or kill termites (see also alpha-cypermethrin).

The synthetic pyrethroids are synthetic chemicals similar in structure to the naturally- occurring pyrethrums. Like other pyrethroids, bifenthrin kills insects by affecting the salt balance (sodium channels) in nerve cells. It has a broad spectrum of activity against insects with the main toxic effect on the nervous system.


Toxicity

In mammals, bifenthrin is very toxic if swallowed. It is a type I pyrethrum (as compared with type II pyrethrums such as alpha-cypermethrin), which means that it mainly affects the peripheral nervous system causing tremors; it may also cause difficulties in walking. These effects are reversible and pyrethroids have a good safety record.

In laboratory animals, ingested bifenthrin is poorly absorbed from the gastrointestinal tract and is excreted unchanged in the faeces. It does not accumulate in the body after repeated doses. When applied to the skin, bifenthrin is of low toxicity, is not irritating and does not cause allergic reactions (skin sensitisation). However, bifenthrin is a slight eye irritant. Bifenthrin products are typically of low toxicity by inhalation.

After long-term exposure to high levels in the diet, mice developed benign (that is non- malignant, or unlikely to spread) tumours of the urinary bladder. These tumours are thought to result from chronic inflammation of the bladder wall, and were not seen in other species, or at lower doses. Bifenthrin was negative in most genotoxicity tests (that is, tests to assess its potential to damage the genetic material of cells and cause mutations or cancer). Bifenthrin did not cause birth defects or other reproductive problems in laboratory animals.


Poisons scheduling in Australia

Bifenthrin is included in Schedule 7 of the Standard for the Uniform Scheduling of Drugs and Poisons, with products containing less than 10% included in Schedule 6. Products containing less than 0.5% bifenthrin are exempt from scheduling. Bifenthrin products for termiticide treatment around the home can only be used by licensed pest control operators who have been trained in their handling and use.


Ecological and environmental effects

Bifenthrin is poorly soluble in water and exhibits strong soil binding properties and low mobility in soils. Neither plants nor animals metabolise bifenthrin extensively. These characteristics tend to make bifenthrin very stable in the environment. The chemical is highly toxic to fish, aquatic invertebrates and bees, but only slightly toxic to birds.

Thanks all for your help and replies
My customer is not a fan of chemicals in or near his proposed vegie bed. I think he will just look at replacing the wood in years to come if or should it be when the ants have demolished our handiwork.

Originally Posted by comgreserv

Thanks all for your help and replies
My customer is not a fan of chemicals in or near his proposed vegie bed. I think he will just look at replacing the wood in years to come if or should it be when the ants have demolished our handiwork.

The Borax treatment is about half as toxic to you as the salt you sprinkle on your steak each night and the ethylene glycol is not meant to have any detrimental effects whatsoever in the solution that you would be using it in. Propylene glycol is reputed to be slightly harmful but once again in the solutions you would be talking it would be declared totally safe. In theory the boron is what makes the wood not suitable as a food source for termites and other ant species and also controls the rot/decay in the wood by killing the spores and the ethylene glycol allows it to penetrate the wood tissue and be retained in said tissue. at the moment I would say that there is no safer treatment on the market. would be more than safe for a vege bed. You could also treat the weathering faces with something like sump oil. The chances of it getting into the soil are very slim and it would act as a very good timber preservative. (just do not paint the inside with it.)