On 11/11/2014 18:21, Andrew Gabriel wrote:
In article ,
Cursitor Doom writes:
This wood they sell as treated (got a sort of greenish tint to the
outside of it; slightly pinkish inside) - is it sort of like thoroughly
soaked in the preservative chemicals so it penetrates right the way
through or is it essentially just a superficial coating of just a few mms?

The treatments allowed to be applied were seriously dumbed down some
years back. Outdoor garden timber - the treatment now is pretty much
completely useless. OTOH, I do question if it was ever needed - my
28 year old featherboarded arris rail fence is still fine, and I
never treated it with anything, and it wasn't pre-treated timber.
Providing timber gets a chance to dry out from time to time, it
doesn't rot very fast at all.

The only timber which was still allowed to be pre-treated with anything
nasty enough to really work was roofing battens. Don't know if that's
still allowed today.


Roofing battens have such a high moisture content it's difficult to see
how there would be room for any preservative. At least twice the weight
of joinery quality IME