Chris George wrote:
On 29 July, 15:17, "Cash"
wrote:
blod wrote:
I am putting up a tanalised shed but I want to make the roof a bit
wider and longer, for more of an overhang, and put up a fascia board
to support gutters, and I want to add wider decorative trim on the
corners. I want to use tanalised woof for all these things but the
choice of wood where I live is very limited. So I thought I might get,
say, a 3 inch square length of tanalised and use the table saw to cut
thinner lengths. Or I could plane down a 1" thick board....anyway,
would that work? I don't know if the pressure-treatment goes all
through the wood or if newly cut edges would be as prone to rotting as
ordinary softwood.
The local timber yard sells feather edge boards that would be good (if
cut narrower) to make the decorative trim for the corners of the shed.
With that thinner wood (max about 1/2 inch) be pretty much sure to be
treated all the way through?
blod,

It would depend on how the timber was tanalised. If it was merely dipped or
soaked, then it would fairly superficial - if it was pressure/vacuum
treated, then it should 'right through'.

As a matter of interest, I have a fence made of tanalised timber that was
erected some 10 years ago (all pressure treated) which is as good now as
when it was done - and the 100mm square posts showed tanalising right to the
core (as specified by me).

Cash

Tanalith process is defined as a pressure impregnation
anything else is immersion

Old CCA was good but the Eurocrappers have f****d up the process by
taking out the A and as a result is it not so effective
Chris

Well I dunno about all that. I bought a LOT of 'pressure treated' wood
and no WAY did the greenish cast go more than 1mm into it.

Maybe a bit more at the corners. Oh it penetrates all right..its not
just a surface treatment, but the price of it alone suggests that its
not fully impregnated with copper salts. No way! It would be hugely
expensive.

Its just a way of getting treatment beyond the immediate surface, it
doesn't fully penetrate the wood by any means.