Red cedar UV protection

TheCyclingProgrammer

My garden office is being installed at the end of September. The two visible sides facing the garden will be clad in western red cedar. The outer sides will be european redwood.

The supplier recommends treating the cedar within a month of installation if I want to protect and preserve the colour. Alternatively I could just let it silver naturally but I'm aware that red cedar will go patchy and take many years before its a nice uniform silver colour.

I'd prefer to maintain the colour for as long as possible with the minimum of maintenance so can anyone recommend a specific product? I'm looking at Osmo UV protection oil which claims to greatly slow the silvering process for up to 4 years with a single application:

http://www.osmouk.com/sitechaptern.cfm?bookid=Products&chapter=82&page=262

However it claims you need to wait 12 weeks before you apply it - I'm not sure why and would have thought the UV damage would have been done in this time.

Silvatimber, who are a supplier of cedar cladding, recommend Sansin SDF with a claim that it lasts 3-6 years. It's very expensive but I have no problem paying for it if it does the job but I don't really want to change the colour of the timber.

https://www.silvatimber.co.uk/wood-care/sansin-sdf-wood-finish.html

Is there anything else somebody can recommend?

TheCyclingProgrammer

I may be answering my own question here but it looks like the Osmo oil (clear satin) is the right option.

Apparently it needs 6-12 weeks to weather slightly so the pores of the wood open up - if it fades a small amount in that time the oil will restore it slightly and protect it for several years.

Has anyone got any experience with this on cedar?

PrinnyPree

Hi I'm looking to build a cedar garden office in June I'd love to hear any of your tips. I'm also getting my cladding through silvatimber, sorry that you didn't get any answers to your initial questions. Hope the build went well, how did it fair during the winter months?

john.h

I made my fence from western red cedar from Silvatimber. I coated it as soon as I put it up with Osmo uv protection oil. It’s now been up around 2.5 years and it has stayed its original colour.
I would post a pic but don’t know how to :rotfl:

John..

TheCyclingProgrammer

I used this in the end as it was suitable for both the cladding and decking whereas the Osmo isn!!!8217;t suitable for decking.

https://www.wood-finishes-direct.com/product/manns-premier-uv-decking-oil

It!!!8217;s been 6 months so far. There has been some mild fading down of the south facing side but it!!!8217;s mainly retained its colour. The east facing side shows no fading at all. Still got summer to go yet. I!!!8217;m not convinced these products will prevent fading or silvering completely but will just slow it down. I will give it a topup coat in Autumn.

I!!!8217;ll post some photos later.

DavidT67

I applied Osmo UV Protection Oil Clear coat to our Cedar Garden Room, six weeks after construction in Spring '17 and then again at the end of the Summer '17.
It still looks good with the original colour tone.
The rear side which I can't reach as it's up against the boundary line, looks distinctly pale silver in comparison.

woodingabout

I moved to Woodoc and I'm really happy, outlasts Osmo and you can choose from the totally matt (non film forming) a polimerising oil - Wodooc Wood Dressing - or the film forming ones Woodoc 50 Gloss or matt. They are clear, but all have UV protection.
Whenever I had to deal with blackening/silvering I've used their Wood reviver, it works a treat; however sometimes areas are a bit too far gone, whenever I didn't want to spend all my time sanding down these discoloured bits, I have added one of the tints just to have a uniform finish (they are not opaque so I liked the way they worked showing the wood). Look at their site for more info woodoc.biz

beckyyc17

I asked Osmo about this myself. From what I remember, a weathering period is necessary as some wood species, including Cedar have water-soluble coloured extractives which leach out naturally when weathered. The UV rays should not damage the wood species within this period.

I would strongly recommend the Osmo UV Protection Oil, I have used it on a Cedar lodge and the colour has stayed the same without any greying of the wood.

I've noticed a company called All Finishes are doing a special deal on it at the moment, where you get 20% extra for the price of a 2.5L tin :j

woodingabout

I use to listen to that marketing line, but never quite believed it, a mate who installs garden offices found that when using Osmo on cedar the oil of the cedar would just "push it out" within 6months or so. An he found himself, a few times, called back to re-finish the surfaces. He eventually changed to Woodoc and never had any issues, in fact he told me about Woodoc and its lines.
In any case, I love the colour of Cedarwood and don't quite see the point of letting the wood going grey and then treat it, simply because a certain product can't cope with it.

lastdayofmay

I have a similar issue to this, but having read up about it on the web I'm even more confused.

I am also having a garden building built that will be clad in Western Red Cedar. I actually quite like the look of it when it fades, so I don't think UV protection is the main issue for me. There seem to be a number of factors that can affect the appearance, including water washing out the colour of the timber, mould growing on the timber, heat causing cracking etc... and there seem to be a lot of products on the market that can help with these. For me I think the main problem I want to avoid is the blotchiness that you get when rain unevenly washes out the colour of the Red Cedar.

I'm considering a product called Roxil Wood Protection Cream that waterproofs the wood and should therefore stop the colours leaching out, but would be interested if anyone has any experience with it or advice before I buy. Preferably I want a product that doesn't dye the timber.

lastdayofmay

Just to add that the Western Red Cedar that I have ordered is British grown. I've been told that this is pretty decent but not as durable as the stuff that is imported from America. Not sure if it affects what treatments I can use.