Should I bother to treat a tanalised shed?

[brass monkey]

Not with the occassional Mars bar, but with wet stuff. If so, which one? Cheers.

[Frank Erskine]

Creosote. The real stuff.

You can buy it in bulk (>= 25 'litres') for non-domestic use, such as telegraph and power poles, railways sleepers, farm fence-posts, sheds, and so on.

TBH it's never been bettered, despite numerous serious tests with truly poisonous compounds of sodium fluoride, phenols, arsenic, various chromates etc (Wolman Salts), copper sulphate and so on.

The stuff sold in the sheds is really only wood dye.

[MM]

It depends. Recently I have seen water-based "creocote" and the genuine oil/spirit-based stuff. I have used the latter when creoSote was no longer available and the product worked exactly like creoSote. No difference. Same soak-in property, same stench, same long-term durability.

MM

[stuart noble]

Interesting. It's obviously something that lends itself to emulsification. I believe they were using water based bitumen during WW2

[The Medway Handyman]

I would, for two reasons. It keeps the colour, acoiding that dirty silver grey look and you can never protect timber too much.

B&Q own label is as good as any IME.

[stuart noble]

To me the silver grey looks a lot better than the garish Ronseal type colours.

[Dave Osborne]

Proper creosote is still available. Go to your local agricultural/fencing timber supplier and ask for their advice.

They will have oil-based approved creosote substitute, waster based creosote substitute and real industrial-quality creosote (but usually only in large quantities).

When you ask for the real stuff and the sales assistant says "Is this for the farm?" the correct answer is "Yes".

[Huge]

one's exposure to benzopyrene...

[The Medway Handyman]

Isn't the correct answer Oooh Arrr?

:-)

[dennis]

It doesn't work. There have been a lot of tests that show it doesn't work when its painted on.

Assuming the shed has a waterproof roof with adequate overhangs and isn't sitting in a puddle there is no need to treat a wooden shed anyway. It should dry out before root can set in and all that happens is it goes a different colour. Hence the dyes to make it whatever colour you want.

Its the same with fences, mine is now >30 years old.. the creosoted posts have long rotted (concrete spurs are your friend) but the feather edge is still there, never been treated with creosote since new and only twice with dye to make it a pretty colour (according to the wife).

[MM]

Or: Got any string to hold me trousers up?

MM

[Davy]

Painted on creosote will not prevent rot. But it will prevent moss and algea growth which can blacken fences etc. I use light-coloured creosote substitute when I want wood to remain clean with a slight chestnut colour. Preventing moss also makes decking less slippery.

DAvy