Treatment for Outside Rough Timber

Are you looking for a preservative or a paint?

For preservatives, I've used Sadolin (classic followed by one of the advanced products) and Sikkens.

For paints, take a look at Jotun products. Trebitt (translucent) or Demidekk (opaque). These are very good materials and available in a broad range of colours - basically whatever you want.

.andy

To email, substitute .nospam with .gl

Pick the right timber in the first place. Not much else helps.

It may depend on the specific situation as to whether the treatment is suitable or not but a lot of rough timber constructions have been painted with used engine oil to very good preservative effect. Decorative is something else.:)

Hi,

What sort of wood, what colour and what weather will it be exposed to?

cheers, Pete.

Hi, The wood is mainly in the form of old (up to 200yrs) oak beams used in the outside wood framed construction of an old French cottage which I have.

The colour I'm looking for is anything from dark brown to black.

Just get clear solvent preservative with wood stain. Or stain it with poster paint or cloth dye and then put preservative and linseed oil on it. Preservative reacts badly with paint so I can't recommend the last idea.

Sort out the drainage then, so that it isn't left sitting in pooled water. Apart from that, you should see a few more centuries out of it. Oak is one of the most long-lived external timbers you can get, so long as it's in large sections and you don't mind aesthetic splits.

"Black Jack" bitumen primer (cheap, get it anywhere, or from Screwfix

- cheaper in bigger cans though) is a good treatment for exposed oak framing, if it's already black. When exposed to real weather it lasts better than most of the deliberately poisonous things. It's also great for camouflaging new oak into old timbers, although a wash of

Poisons are for clearing up bug infestations, or for treating the surroundings of a fungal outbreak. They aren't really persistent enough for long-term prevention, unless you're using very high concentrations of metals (such as tanalised timber). Although fungicides may also be effective pesticides, few of the pesticides have any effect on fungi ! Use the appropriate stuff for the problem you actually have, don't just blast away with whatever the advert tells you to buy.

Creosote was the best IME. We are just trying the latest emasculated version so the jury is still out on it. Smells bit like old one and looks the same.

Hi,

Try dark oak or ebony Sadolin or Sikkens, if you call them they would recommend the best type to use.

Or ask the locals what they do to stain theirs :) There is a way of 'ebonising' wood with iron salts though it would be well worth trying a test patch first.

Or maybe just linseed oil if a natural finish is OK, it will darken over time some but not to dark brown.

cheers, Pete.

Thanks to all who contributed the useful suggestions - much appreciated.