Thread: Chances of old house stumps and fence posts being treated with chemicals?

Hi 419. My understanding is that redgum was used because of it's inherent durability (although only a class 2 timber) and availability. I also believe that due to its density that it is too difficult to "treat". Having pulled countless examples out of the ground, it does rot eventually - further "evidence" of no treatments.

Just be aware that while redgum stumps may not have been treated they may have sprayed the undersides of the floor boards. Floor boards from our 100+ year old house stink when I cut them - don't know what it is but I have stopped cutting them.

Hi 419

Would it be possible that you posts were sprayed for termite or other pest control over the years?

I was involved in the international trade in timber in the 1970's and a hell of a lot of chemicals were used over the years - over 100.

• CCA was only used on pine and is fairly easy to identify,
• Creosote always smells,
• The rest are virtually undetctable unless you have a forensic lab,
• Virtually all imported timber was treated - AQIS rules,
• Timber mills exporting often dipped everything, easier than two stock piles,
• Lots of treated timber sold locally, treatment frequently not disclosed.

Copper sulphate also known as Bluestone was often used as a preservative for inground timber. Particularly for class2 and lower graded timbers.
River red gum is a class2.

A common old rural trick was to paint exposed timbers with a dilute mix of used sump oil. Often diluted with kero, occasionally petrol. Especially house stumps, bearers, fences and support structures in open sheds.

I guess it was a bit like old tires; 'twas something most farms had in surplus, convenient to hand and otherwise pretty much useless. Needed re-application every few years on areas exposed to heavy weather but all it cost was a bit of time & labour.

Those were different days... and it's a practise I know was continued on in some areas until late last century.


Unless the timber was treated this way in the last 40 years or so, it's hard to pick. Although I've noticed distinct "penetration lines" when cutting up old fence posts I know were regularly sump-oiled until about 50 years ago, along with traces of an unpleasant smell. FWIW I wouldn't call the smell 'petrochemical' but I'd be reluctant to use it for firewood in the house.

Old trick?? We still do it for rural fence posts, and it does seem to make a difference. Mix up sump oil with the last of the creosote I still have in my shed. I believe creosote is only available to "professional users" these days, which almost certainly doesn't include me.....

Originally Posted by Skew ChiDAMN!!

Those were different days... and it's a practise I know was continued on in some areas until late last century.

I was still doing it up till about 20 years ago on the back (soil side) of untreated timber retaining wall sleepers.

I'd forgotten about using it on fences, which was common when I was a kid in the 1950s and 1960s, and maybe a bit later.

I have a vague recollection that some sort of linseed oil preparation was also used on fences in the same era.

As Mountain Ash has pointed out, red gum is pretty dense and the older stuff was really dense, so I doubt there was much penetration with these coatings on fence posts.

Originally Posted by Mountain Ash

Hi 419. My understanding is that redgum was used because of it's inherent durability (although only a class 2 timber) and availability. I also believe that due to its density that it is too difficult to "treat". Having pulled countless examples out of the ground, it does rot eventually - further "evidence" of no treatments.

Until now it's never occurred to me that, apart from availability and cheapness, pine is probably the most commonly treated timber because it's significantly less dense than hardwoods (in the sense of density rather than strict hardwood / softwood classifications) and responds best to pressure treating.

I've found that there is often surprisingly little rot on the in ground part of red gum house stumps. It's usually an 'hourglass' rot area just above and just below the ground surface, presumably because that's the area of continuing instability in moisture and whatever else it is that eats at the wood with fairly stable conditions above and below that area.

Originally Posted by GraemeCook

Hi 419

Would it be possible that you posts were sprayed for termite or other pest control over the years?

I was involved in the international trade in timber in the 1970's and a hell of a lot of chemicals were used over the years - over 100.

• CCA was only used on pine and is fairly easy to identify,
• Creosote always smells,
• The rest are virtually undetctable unless you have a forensic lab,
• Virtually all imported timber was treated - AQIS rules,
• Timber mills exporting often dipped everything, easier than two stock piles,
• Lots of treated timber sold locally, treatment frequently not disclosed.

Thanks. That's the sort of not generally known information I was wondering about. I guess it's a bit of a lucky dip with recycled red gum and other native hardwoods.

On the plus side, by the time I've jointed it, resawn it, thicknessed it, and coated it there's probably little of nothing left or at least exposed of what must have been a largely surface treatment on Australian hardwoods.

Originally Posted by rustynail

Copper sulphate also known as Bluestone was often used as a preservative for inground timber. Particularly for class2 and lower graded timbers.
River red gum is a class2.

Thanks. I didn't know that, but it's still used as a garden chemical and still known as Bluestone. Just a moment...

Originally Posted by Mr Brush

Old trick?? We still do it for rural fence posts, and it does seem to make a difference. Mix up sump oil with the last of the creosote I still have in my shed. I believe creosote is only available to "professional users" these days, which almost certainly doesn't include me.....

Mr B

Just be aware that the primary concern with creosote, but not the only issue, is that contact with the liquid (and even the fumes when first applied) removes the skin's natural protection against sunburn. This is not quite so acute in the higher latitudes, but is a serious issue in most of the Australian climate. Sunburn can be excruciatingly painful in a matter of minutes to affected skin. The people working at Koppers logs were never able to go into the sun and it was one of their managers who explained exactly what happens after I had experienced such an event many years ago.

Regards
Paul

Originally Posted by GraemeCook

Hi 419

Would it be possible that you posts were sprayed for termite or other pest control over the years?

I was involved in the international trade in timber in the 1970's and a hell of a lot of chemicals were used over the years - over 100.

• CCA was only used on pine and is fairly easy to identify,
• Creosote always smells,
• The rest are virtually undetctable unless you have a forensic lab,
• Virtually all imported timber was treated - AQIS rules,
• Timber mills exporting often dipped everything, easier than two stock piles,
• Lots of treated timber sold locally, treatment frequently not disclosed.

Not to mention all the proprietary brands - like Tanalith. I've added a link to the Hemel SDS for Tanalith to highlight the cocktails of chemicals used for wood preservation typical in many of the brands used. https://hemel.com.tr/Data/EditorFile...nalith-SDS.pdf

Almost all wood has been "treated" in some form against insect or other biological degradation, from a simple spray with Borax in boutique mills, to complex high pressure treatment, dockside fumigation of logs (methyl bromide etc), heat treatments .... look up "International Standards for Phytosanitary Measures" and other regs - Ultimate Guide To Pallet Markings - Universal Pallets BITCON - Access Denied

There are heaps or regs - Timber Utilization & Marketing Act - approved preservation treatments .... restrictions on movement ...... yadda yadda

At least we have some idea at source from commercial vendors, but once it has left its primary processing origin anything could have been applied to it.

I have used several old redgum posts and have never noticed anything on them or any smell after re-sawing. They have all been from suburban properties which may explain that. I have only ever used the sections from above ground.
There is some amazing colour and grain patterns in some of them.

Originally Posted by Chesand

I have used several old redgum posts and have never noticed anything on them or any smell after re-sawing. They have all been from suburban properties which may explain that.

There's plenty of termite areas around Melbourne's suburbs, but I expect people probably wouldn't bother with the cost of protecting fences where they might, as we have, protect their sub-floor areas on the houses.

Originally Posted by Chesand

I have only ever used the sections from above ground.

Me too. Sometimes the below ground parts of house stumps are in pretty good condition once the outer surfaces are removed, but they've been damp for four or five decades at least and I think you'd need to resaw and then air dry them for a few years to get reliable timber, assuming they didn't twist or warp while drying.

Originally Posted by Chesand

There is some amazing colour and grain patterns in some of them.

Which is why I'm mildly obsessed with red gum.