Tanalising - Is there any point?

capeverde

Just thought Id put this up for discussion. Since the harmful ingredients were removed and the new tanalithE brand launched, I think its pretty pointless having timber pressure treated. Regarding benefits, I cannot see any. Ive seen timber in contact with the ground rotting after just a couple of years, despite the 15 year pledge of the manufacturers. Add to this, if you are using thinner timber like cladding, it expands by 5-6mm per plank after treatment so when it dries, you will have very little coverage and even gaps. Ive air dried timber in my factory for 2 months and its still not dried out. When you use the timber immediately, if it comes into contact with sunlight, it will also crack and split badly. This is not just the thinner timbers, but also things like 4x4 or 6x6 posts. Ive come to the conclusion it is far better to use kiln dried timbers and then apply the correct amount of oil based preservatives once the project is complete and before it is open to the elements.

leveller2911

Agree 100%..............:beer:


If the timber is in contact with the ground I would use either green oak (no sapwood) or a durable hardwood like Iroko but the downside is cost.

Tanalising timber breaks down once you have a cut end.In the old days you could seal the end with the original "Tanalith" which was evil stuff but they banned it and since then tanalised timber is rubbish.

As you rightly point out when the process is done more often than not the timber comes out saturated and once it dries out it shrinks back.

As a guide when air drying slabs of timber you allow at least 1 year for every inch so 4" air dried should be left for at least 4 years or kiln dried for at least 3 weeks which is expensive.

They also use the least durable timber known to man(European Whitewood) and impregnate rather than use a decent timber to start with, you should never see the "Pith"(centre of the tree,its like cork) on a 4" post so its also the way they cut the timber thats part of the problem.This would increase costs and Joe Public don't like paying for quality timber.For instance Balau hardwood decking is vastly superior but twice the price of Tanalised softwood.May be an option to use "Greenheart" too which they make beach groins from.

The tanalising industry is run by people who know very little about timber, which should set alarm bells ringing.

capeverde

Teak and Iroko are pretty good in contact with the ground, but I would disagree with Oak. We did a job out in the basque area of france last year and they guy had some 10 x 10 oak posts supporting his porch. They were rotting and had only been up a few years. I get stainless steel jacks made now to keep the timber off the ground. Basically 100mm x 100mm x 5mm plates with a 16mm threaded bar welded to one end and going through the top plate with a nut welded to it. Its easy to level things up and works fantastic. You obviously have to drill up into the post for the bar to recede, but this only takes a short time. I think they cost me around 15 quid each to have made by a local engineering company.

Back to tanalising, I was chatting with the owner of the woodyard we use yesterday about it. He's of the same opinion that its pointless, but the general public have been sold on a process so if they dont provide it, they will lose business. I feel sorry for all the DIYers who buy shiplap straight out of the plant to build a shed. It will look ore like a 5 bar gate as soon as summer comes.

leveller2911

capeverde wrote: »

Teak and Iroko are pretty good in contact with the ground, but I would disagree with Oak. We did a job out in the basque area of france last year and they guy had some 10 x 10 oak posts supporting his porch. They were rotting and had only been up a few years. I get stainless steel jacks made now to keep the timber off the ground. Basically 100mm x 100mm x 5mm plates with a 16mm threaded bar welded to one end and going through the top plate with a nut welded to it. Its easy to level things up and works fantastic. You obviously have to drill up into the post for the bar to recede, but this only takes a short time. I think they cost me around 15 quid each to have made by a local engineering company.

We do the same and have them either galvanised or made of stainless steel. As you say they work well and in years to come can be easily replaced if necessary. Re: Oak , people make the mistake of using Oak that still has the Sapwood and this rots quickly.I'm not saying you do btw but many do.We even see Oak windows and doors containing sapwood.

Back to tanalising, I was chatting with the owner of the woodyard we use yesterday about it. He's of the same opinion that its pointless, but the general public have been sold on a process so if they dont provide it, they will lose business. I feel sorry for all the DIYers who buy shiplap straight out of the plant to build a shed. It will look ore like a 5 bar gate as soon as summer comes.

I'm with you on this one.They have done a very good marketing job with tanalising but its also the timber they use thats the problem.Its been a race to the bottom with tanalising, people insist on cheap being the key rather than quality.

Its no good building a quality house on poor foundations.

Would also point out its all very well giving a 15yr limited warranty ,when they do accept liability they will provide replacement materials but not the labour cost of rectifying the problem.