Wood worm holes again !

[pwdrive]

Goes to show that the chemicals don't work

How far in to the wood will they soak? That surely depends on the wood, plus how it's been treated? And how long do they remain effective once the fluids have evaporated? As far as I can tell, the health risks outweigh the potential benefits by quite some margin.

As an aside, it's quite surprising how humid houses can be - especially these modern hermetically-sealed ones!

Chemicals do work, it's what the whole tanalizing industry is based on.

The fluid will penetrate as far into the wood as far as the species, moisture content and the cut of the wood dictate.

As a rule, sapwood content will absorb fluid and hence have the highest chemical retention, heartwood wont unless it's been incised (or rotten) and even then with most species the fluid penetration due to incision will remain close to the incisions, Scot's Pine is the best softwood for heartwood incision, that's why the utility companies prefer it for their utility poles.

Most old radio cabinets will be made from plywood, face veneer aside, the plywood veneers used in the construction will generally be low grade sheets, most commonly softwood and most commonly wood from the sap band, that's the part of the tree that in timber production terms is of the least value unless the stand has been high pruned somewhere around the stands mid rotation, if it has then all subsequent growth will be knot free up to the pruning height apart from any possible epicormic shoots that develop after the pruning operation, ever seen a long length of new softwood joinery timber that's knot free? Well that's how it came to be.

The little beasties love the sapwood and the animal glue that's used, they're like most living things, they go for the easy stuff, munch munch.

The fluid is just the carrier, once it's done its job it matters not that it evaporates.

Houses don't seal themselves, all modern houses that are legally built and signed off have to comply with the building regulations, the regulations require means of ventilation, it's the occupants that seal them up, more fools them.

Lawrence.

[Mark Hennessy]

My comments are specifically aimed at the domestic timber treatment industry, that trades on FUD (fear, uncertainty and doubt) and the promise of "mortgage money" from people involved with long, complicated buying/selling chains (similar comments could also apply to the damp-proof injecting industry). Meanwhile, perfectly viable and historically significant parts of buildings are being ruined by these people. And as for the "chemicals", we're living with them - moreover, we're living with a veritable cocktail of them, and no-one knows exactly what happens when you mix them all together.

I've no idea how many times my house has been treated for woodworm, but I know that it's been done at least once in recent times (by the previous previous owners, perhaps 8 years before we bought it), and no-doubt it was done by owners prior to that. So if the chemicals work, how come I saw beetles emerging when I first moved in? And how come they've not emerged since, especially given that I haven't treated the wood? All I've done is dry the place out. It's that simple.

The answer to damp or woodworm is obvious - heat and ventilation. But none of these "surveyors" will tell the home-owner this because obviously they're commission-based salespeople. Truly independent timber and damp specialists are few and far between, sadly, but they do seem to be growing in number at last.

Tanalizing is a whole different ball-game, but we're discussing timber in a domestic environment, not fence posts.

I certainly agree that wood-worm is especially fond of the ply used in most "woodies", and have often thought that the animal glue must a factor.

[pwdrive]

I read what you say Mark but on the other hand....I once converted an old agricultural barn to residential use, first job on the barn was the roof or what was left of it, rafters shot, purlins shot, A frames...well not as bad as I originally thought, there were four of them in total, one of the legs in one of them was rotten, replaceable/doable, the rest of the legs and collar beams were riddled with woodworm holes, I mean really riddled but no sign of collapsing, some frass was fresh. The timber was old Baltic pine.

Anyways the building inspector came out to ok the septic tank/drains etc, I got him to look at the riddled A frames, he got a screw driver and sunk it into the wood until it hit the heartwood he said they would be fine (Gulp) but I must treat them, I used an off the shelve woodworm killer, can't remember the make, probably Cuprinol or Ronseal or something similar, at least a couple of large cans as I remember, gave the timbers around four good soakings, lived there for twenty years, no frass.

Lawrence.

[pwdrive]

Just to add to my previous post, plywood made with some of the modern glues can be pressure treated, some might or might not find that useful.

As a test, obtain an off cut of low grade plywood such as shuttering ply and if you can, find some solvent based wood preserver or even the newer substitute stuff (still smells like solvent but less so) and brush it on, It'll suck it up, almost instantly in most cases, I did the flooring sheets in the new cabin down the woods before I laid and fixed them down, that was shuttering ply and Ronseal wood preserver (the newer stuff) Four 8ft x 4ft sheets took most of a 5 litre can giving them two coats all round.

I did the same in the original cabin, that stood for 15 years before it was destroyed, unheated unless we happened to be staying there, no woodworm, and that's at a location where there is lots of dead/decaying trees around.

Lawrence.

[Mark Hennessy]

I had a similar story with the joists in my front room. They had been severely eaten away, and as a result, bits of the floor had sunk. In once place, where there was once a 2 by 4 resting on the brick wall, there was now a 2 by 2!

I was impressed with how solid the floor felt, despite the attack. Looking closely at the old joists after I'd replaced them, you could clearly see the difference between sapwood and heartwood, and some informal testing showed that the loss of sapwood made surprisingly little difference to the strength of the timber. It was really quite impressive.

I need to repeat the exercise in the back lounge (above the cellar) - there is a lot of historic damage, but no real loss of strength. I have 2 or 3 options on the table, but there's no rush - it's not going anywhere...

[Radio Fixer]

All very interesting and the knowledge of the subject on this Forum is impressive.

Lot to be said for a relatively constant heat and ventilation.  We don't save pennies having unheated rooms, well there aren't any actually as we both have hobbies that fill them up.  But a neighbour went for the full cavity wall treatment that over-spilled and virtually sealed the loft.  Had water dripping off the rafters eventually.  Got the so called 'Pros' back and they put vents under the tiles.  What with? a  piece of timber wedging them up I suspect.

This has been said before but us old boys repeat ourselves  ... somebody may not have read it before.

Never thought I would be an old boy !! Gary

[pwdrive]

I had a similar story with the joists in my front room. They had been severely eaten away, and as a result, bits of the floor had sunk. In once place, where there was once a 2 by 4 resting on the brick wall, there was now a 2 by 2!

I was impressed with how solid the floor felt, despite the attack. Looking closely at the old joists after I'd replaced them, you could clearly see the difference between sapwood and heartwood, and some informal testing showed that the loss of sapwood made surprisingly little difference to the strength of the timber. It was really quite impressive.

I need to repeat the exercise in the back lounge (above the cellar) - there is a lot of historic damage, but no real loss of strength. I have 2 or 3 options on the table, but there's no rush - it's not going anywhere...

Yes, woodworm has to be quite bad to cause structural failure, same with rot, but I take no chances with rot, I just renew the timber, I think most folks that use the off the shelf stuff probably skimp on its application given the price that it is, all our old chair legs are done in it as these have been in less than ideal storage since we last moved, legs in four containers, fill containers up with stuff and leave for a few hours to stand, brushing all the way up the legs when possible, then let dry, light rub with light oak stain all over the legs, wipe off even  then wax up.

Those little critters usually enter via the end grain, usually the early wood and not the late wood, just as a note, the early wood (sometimes called spring wood) is softer than the late wood (sometimes called summer wood), the early wood is the lighter colour of the two, you can do a thumbnail test to prove the point, two growth rings per year. The individual plywood veneers (the cores) can contain early wood or late wood or both, it depends on the trees growth rate and when it was harvested and the thickness of the veneers etc.

So for good treatment using off the shelf stuff apply as much as you can whatever the cost of fluid.

Lawrence.

[ed731pdh]

If your going to bag it up for a year, stick a few sachets of silica gel in and seal tightly. That should kill the humidity in the bag to as near as zero as possible.

[Radio Fixer]

Thanks Ed

[Nick]

Don't know why, maybe I'm over-tired, but when I read the subject line of this topic I immediately thought of Steampunk General Relativity...

...as in wood wormholes...