Treatment of a log cabin – Customer Question

I always try to offer the best advice I can and sometimes, although I recommend our Timber Treatments I do also recommend others to give customers a choice.

A customer wrote to me following our email exchange:

I really appreciate the extra detail as I certainly want to get things right – it’s very good of you to pass on your experience. I have tried to research this online but it’s surprisingly difficult to find good simple advice for a complete novice. A step by step guide “painting a shed for dumb asses” would probably clock up a lot of hits on your site! 😉

I have enough information to make my own decisions now and understand how important the base\DPM and ventilation are.

I’m not going to write such a blog post as suggested for ‘dumb asses’ but it might be useful for you if I copy my email to Mr M that prompted this reply … it does go on a bit but may help with further treatment questions and your understanding of it.

I tend to advise the simplest option – three coats of something expensive. Don’t use ………. on it’s own, especially their shed treatment as it’s terrible for log cabins.

For the first few years of life of a log cabin overkill is a good thing. The wood is kiln dried and I have a personal theory that because it is, the straws that make up wood are still very open, the wood is not really dead as dead should be, it’s an artificial death that we’ve forced on the poor tree.

It’s this openness that allow moisture from the surrounding air content to be absorbed and expelled quickly. Wood is basically made up of loads of straws (needed to suck up moisture from the ground) and it’s these straws we want to bung up. a good few coats of a good treatment does this and there’s never a problem.

Ideally timber should be air dried, But, if we did that you would wait years for your log cabin / table / worktop / kitchen etc and no one wants that.

A cheap treatment won’t stop the transfer of this moisture, there isn’t enough thickness to it to stop the moisture flow. If you use something cheap she will expand and contract a lot in the first year.

Second and third year you will not see it as much, this is because I think the straws have collapsed slightly and / or bunged up. The wood is also more dead and starts to behave more like air dried timber with less movement.

If a building is well ventilated a preserver is not necessary. If a building is not treated at all but is still ventilated it will not come to harm either please see this old girl who has never been treated: https://www.tuin.co.uk/blog/log-cabin-treatment-panic/ (some expected patterns of behaviour though)

Timber treatment and what is recommended by me, the producer, the treatment supplier all have different reasons.

From my point of view I don’t want a complaint from you next year that your building has expanded / contracted and you have a gap somewhere or white bits showing. Of course this is what wood does, it expands and contracts and if a customer understands this it is never a problem, gaps will only appear if it is restricted by a window or door frame being held in place. But your cabin will move quite a bit over the first twelve months.

Sometimes though we see something else: This year we had a problem with one of our show buildings, when the Spring hit, one side contracted quicker than the other due to only one coat of treatment being applied and the sun very, very strong on just one side, the other was in total shade. It meant the straws hadn’t been blocked enough so expelled moisture far quicker than the other side that was shaded. I knew what the problem was and sure enough a week or two later everything was equal and another coat applied and no problems again.

This is why we say 80 – 120 microns depth of coverage, this is also what all the good and expensive treatments will give you. This is why they all say 2 – 3 coats and this is to make sure the depth is thick enough and closes the straws and stops uneven movements.

So, we’ve blocked up the straws which is my consideration and so I don’t have to speak to you next year when you tell me about expansion and I have to explain it and moisture content in the air: https://www.tuin.co.uk/blog/depth-of-treatment-and-moisture-content-in-wood/ and why your cabin is behaving this way.

Next we can move onto the producer both he and I know for certain that wood will never rot if allowed to ventilate. But, we have to account for a dodgy base, water sitting at the base, foliage up against it, insects eating it, bird dropping introducing fungi, no damp proof membrane etc and this is why we will want a preservative. This will stop and inhibit anything forming should a customer be a bit of a numpty and not realise this themselves. This will stop you speaking to me in about 5 years time.

Then we come to the paint / treatment manufacturer – They will be wanting to cover their butt. They will want overkill, belt and braces and will ask you for everything, the same as we should do. If anything happens they will want to ensure you did everything correctly. They also know that wood doesn’t rot if ventilated but also want to watch for the errant customer. If everything is done correctly, no matter what you do to timber it will always be fine. But, if it is exposed to wet and not allowed to ventilated very regular treatment needs to be given.

If all of the above is understood, and the inherent nature of wood is understood such as expansion, contraction, cracking, splitting etc: https://www.tuin.co.uk/blog/cracking-and-splitting-in-timber/ then a good quality treatment is enough, two to three coats applied the building will look good for several years before re-application (mine was using S—— years ago, all I do is pressure wash it yearly, it could do with a touch up but it’s still rot free) If though it is wet constantly then more considerations need to be made to guard against rot caused by damp or infestation.

My advice is good ventilation, a good base and a DPM is the most important thing to give a log cabin a good start in life.

From then on a good treatment of about 2 – 3 coats, ideally something that does it all without under preservatives for ease. Something that looks good and you don’t have to re-do for a couple of years. (our treatments are very good by the way!) Remember what wood does naturally and enjoy it. Bear in mind though as well, one of the reasons why we buy a good treatment for a log cabin is the elasticity, the bloomin’ things move and this elasticity does help a lot especially in the joints over the first year and is very important, cheap treatments will not give you this.

I hope this has helped?

Please also see another post: Log Cabin Treatment Gone Wrong

More … I’ve recently been asked about our treatments:  This post relates entirely to the Tuin range of Log Cabin Treatments and clarifies what and how we recommend they are used if you choose to use our range.

This entry was posted in Technical - Log Cabins and Timber and tagged , , by Richard. Bookmark the permalink.

About Richard

This blog is my personal platform which I do enjoy. It is my own viewpoint and my own ideas. I may not be right and other installers / experts may offer a different view point or a alternative way to do something. I welcome contributions from anybody experienced to do so.

All my blog writing is MY OWN personal opinion ONLY and is NOT always the opinion of TUIN | TUINDECO as a company.

Log Cabins and Garden timber have a myriad of intricacies , I love to give away the secrets, there are a lot!

I enjoy using this blog to expose them so you know what you are buying. I love to know I am causing a few problems in the industry as it can be on occasions less than honest.

I actively encourage everyone to install their own buildings. So many times I would fit and the company I was working for would charge loads for my time, only then to be faced with the embarrassment when the customer says 'I could have done that' and YES you can without paying hundreds of Pounds!

I have over 19 years experience within the garden timber industry. I have particular expertise in garden buildings including the manufacture, design and installation from sheds to log cabins and all the way up to timber framed houses.

In my time I have been involved with virtually every manufacturer and supplier of garden buildings. I have also installed pretty much every make of Garden Building there is from ALL suppliers and manufacturers.

Prior to my career change I was a Watch Commander in the Fire Service with particular expertise in chemical incidents, training, technical design / technology / IT /Procedures / ISO Systems and road traffic accidents. I retired due to a nasty injury after 20 years service.

During my time in the Fire Service, on my days off, I was a self employed fitter for any type of garden building, I worked with most of the well known companies as a subcontractor.

I now work with Tuin | Tuindeco in the UK, supporting and advising on the vast range of products. I keep an eye out for help requests when we a supposed to be closed and can usually get back to you out of hours via email only (wife and children permitting on my days off).

In my private life I consult as an independent expert assessor for companies or private individuals when a dispute is present over their structure which results in producing an impartial report and assessment for whoever requires it. This is often higher valued than a structural engineers report born from my credentials, experience and widely recognised as an 'Expert' in the field.

I am a freelance writer for numerous companies, publications and blogs as well as an independent expert and fault finder for parts of the Industry and consumers with a particular emphasis on timber structures, both framed and of an interlocking design such as log cabins.

I produce numerous articles about timber in general, information on general timber products and specific guides when needed. I hope you enjoy and find my writing useful.

Please contribute and comment to my posts as you would like and I will try to respond as best I can.

Thank you

Richard.

10 thoughts on “Treatment of a log cabin – Customer Question

  1. I spoke with Sikkens who recommended wiping the whole Of the outside of our Watford cabin with methylated spirit, then applying a coat of Cuprinol wood preserver and then using sikkens on top. Do I need the methylated spirits and why do I need Cuprinol if I’m using sikkens as recommended?
    Don’t want to get it wrong!

    • I would follow their recommendations and advice. It’s certainly a good idea to wipe down the surface as a standard practice to remove any grease and dirt. If you are painting in a solid colour it’s also a good idea to use a knotting agent to stop bleed of any sap pockets.

  2. How is is best to apply treatment/paint, with a roller (what type) or a brush? I’m looking at using sadoline superdec on the outside.

    Many thanks

    Ian

  3. Maybe a silly question – but do you just treat the external faces or does the inside also need protecting?
    thanks

    • Certainly the very best wold be for the inside and outside to be treated but this is not always possible or desirable. However, if the building is rarely used or not ventilated then a treatment on the inside is a good idea. It is though important to treat the doors and windows both inside and outside to avoid them warping due to temperature / moisture content variation between inside and out.

  4. How many 2.5 ltr tins of preservative (Carefree) would i need to order to put 4 coats on a ,Rick, log cabin. Also is it best to brush on or spray.
    Many Thanks Roger.

  5. I’m going to be installing my corner log cabin quite close to the boundary. Probably too close to re-paint it – perhaps a 6” gap. So I’m plannning to treat it with the best quality 10 year product, during the build. It’s unlikely to receive much weather beating as it’s in a sheltered spot. I can re-treat the front walls of course. As appearance round the back isn’t an issue – would you say the one treatment will be ok for years to come? I’ll literally have to rebuild her to treat her! Sue

    • As the cabin is very close to the boundary it is not going to be possible to re-treat it so you will need to thoroughly treat it as you build the cabin, try to get at least two – three coats on if you can. As it is sheltered it is not going to receive the same amount of weather as the rest of the building. It will though be important to treat the rest of the cabin and re-do this as required so as to keep the timber at the same equilibrium of moisture content to avoid expansion and contraction problems.

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