Suiable Timber for Garden Arch

[Little Ern]

I am about to build an archway for the garden and was wondering if anyone could advise which would be better - tanalised or untreated timber followed by suitable treatment. I've read differing opinions on this particularly with regard to the tanalising treatment being removed as the timber is cut. The arch is something along the lines of a 'pagoda-shaped' top and the sides and top will be infilled with 'woven' trellis (32x6mm).
There will be the odd decorative groove on the posts and some rounding over of the edges of various rails etc.

Any advice appreciated.

 

[RogerS]

Hi LE

I'd be inclined to go for the tanalised and then recoat where necessary. Rationale being that their tanalising should be much better then me and a brush and some Cuprinol!

 

[PowerTool]

Yes,quite agree - tanalising is a more thorough treatment than a brush :lol:
Just be careful of the dust when machining it.

Andrew

 

[Little Ern]

Good points.
I'll go for the tanalised option.

Thanks for the replies.

 

[ProShop]

tanalised or untreated timber followed by suitable treatment. I've read differing opinions on this particularly with regard to the tanalising treatment being removed as the timber is cut.

Any advice appreciated.

The tanalith treatment is removed when the timber is cut, and can render the treatment useless as there's non left after it has been cut or planed. You can get a supposed tanalith paint to touch up after cutting , but it's not the real thing and it's only suitable for use on end grain.

If the timber comes from the middle of the pack when it's in the tank you'll be lucky to get a couple of milimetres of penetration.

Tanalith treatment comes in various grades, ie the longer it's in the treatment tank and the higher the pressure or vacuum (depending on the treatment plant used) determines the grade. But of course the price is adjusted accordingly .

Most tanalith treatment at most places unless you specify comes with very little depth of treatment (called cost cutting).

It's also worth remembering that tanalith contains heavy metals, and cyanide, so it's advisable not to burn any offcuts.

The word on the street is that it's due to be put on the banned substances list, which I'm suprised hasn't happened before now.

Hope this helps.

 

[Little Ern]

Thanks John.
The points you've highlighted are what was concerning me. I've bought the timber now but will give it a good coating of wood preservative before installing . It seems there isn't an ideal solution apart from using a hardwood.
I'm slicing some 150x38mm stuff to make the trellis (6x38) so I guess there will be little or no tanalith left after this.

Cheers,