Shiplap Cladding advise needed..

23 May 2004
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United Kingdom
I'm just about to clad a worshop. I've been looking at shiplap cladding, and ideally I'd like to use 25x150mm ( the workshop is quite large, so was trying to keep it in 'perspective'), but the only cladding I've seen at that size is the cheap 'white wood'..So it seems to be 19x125mm 'redwood'. Browsing this forum, I've noticed mention of 'treating' or 'tanilising' the wood. Does this make a difference to the performence of the cladding? Could someone point out the 'pros & cons' of treatment? I want to keep the wood looking 'natural', accepting it will yellow, so does the treatment change the appearance/colour of the wood. And what is the best clear preserver I can use to protect the cladding?

Finally, is there an alternative I can use to shiplap if keeping the natural look is not practical..

Cheers in advance
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heeelllooo ellal

i have just completed my workshop using 19by125 tounge and groove treated
i recomend getting the wood treated it should double the life off the wood and with retreating every few years it should last for ever :LOL:
it starts out with a greenish tinge fades more to a fawney very light brown colour
sending it off to be treated costs about 20% more

the actual size of the boards[coverage area ]is 113mm and they finnish up about 13mm thick after planing and the t and g moulding

Did you put anything on the cladding after it was treated , or did you leave it at that?..and when you say 'retreating', what with?

havent got round to retreating it was only up and watertight at easter so its only six months old i have some pictures of how mellow the coulour is i am just trying to work out how to get them from photobucket to here :D
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ellal said:
And what is the best clear preserver I can use to protect the cladding?
Tung oil is the best treatment for wood and so easy to do, just wipe it on. Use it on my summerhouse, there is a picture of my summerhouse on here with tung oil but I can't find it :LOL:
Tung oil.. I've never heard of this, so where is it available?

To start with use 50% of white spirit mixed with 50% of Tung oil and rub it on with lint free cloth.

Also see this previous post
checked out that site, and was puzzled by the description 'weather resistant', and ideal uses - kitchen worktops!...

I also notice it says 'for the first few coats dilute with white spirit' many coats are needed in total?
just one more thing..with the tung oil, or any other treatment, is it best to coat both sides of the cladding prior to putting it up, or is is sufficient to just coat the outside


This is the one I have, it's a little misleading but it's for external as well as I have rang them about it. Just coat the outside but nothing to stop you coating on the inside if you want to and believe me it is 100% waterproof because the oil penetrate into the timber, the more you put on the better it is. The chinese use it on their boats for the last 600 years, isn't that telling you something ;)
Danish oil is the not the same because the tung oil have a longer drying time to penetrate into the timber.

I'm doing my bay windows with 4 coats so far and you can see the rain bubbles on it and not even soaking into the wood.

Also have a read here
Thanks for all the info. Very helpful, and it looks like I'll be trying the tung oil..

I used to make sheds and summerhouses for a living and I would always use tanalised timber. I would guess this is what big all is refering to as 'treated', but I may be wrong.

This treatment involves pressure impregnating the wood with a preservative which gives it a long life. It gives it an attractive greeny appearance but this soon fades to a grey/brown.

If you have a look at timber decking the chances are that it will have been tanalised, which will give you an idea of the colour.

Most timber-yards will sell tanalised shiplap or will have it treated for you. If it still seems at all wet when you have bought it the leave it to dry for at least a week as it will shrink a surprising amount. Make sure the air can get all aroung the lengths rather than leave them in a pile. It is common to use battens to seperate them.

One advantage with tanalising is that you can then over-treat it with almost anything. You could stain it and then oil it for example.

Tung oil will waterproof the timber but it will not protect it from boring insects and if the wood develops any shakes (splits) after it has been treated then this can allow the wood to rot. Also, tung oil would ideally need re-coating every year whereas tanalith lasts for about 20 years I think. When you are re-coating with tung oil you may not be able to get to all the bits of endgrain which are the most vulnerable ares to water ingress.

You can buy clear preservative with which you can treat the wood yourself if you do not like the colour of tanalised wood, and then you can apply oil over the top if you wish.
dont think they tannalise it any more because of the various chemicals, i think its just pressure treated with preservative, but does more or less the same thing
You may be right, I think tanalith contains copper and arsenic in small quantities to prevent fungal growth and the timber-yard was not meant to send it out until it had dried for 3 days as it can be harmful to humans when wet (harmless when dry) but if we were building a barn and the timber was delivered in the morning, then by the afternoon there would be puddles of yellow liquid under the stacks of cladding.
note to self - never temp fate by stating 'one more thing'..!

I've been looking around for shiplap, and all the timber merchants supply it in random lengths unless they happen to have what you want, and with 300m+ that's quite difficult..I was hoping to have complete lenghts everywhere, but unless I find those lengths, I will have to have joins..What would be the best way of making sure the joins are completely sealed if I have no option to do it this way?


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