Sioo:x - DIY or factory sprayed?

[Roz]

Hi, 

 

I'm keen on getting our larch cladding treated with Sioo:x but not sure whether to pay for it to be factory done, or do it ourselves. Has anyone DIY applied and how much of a pain is it? Do you need to apply to both sides?

 

Thanks!

Roz

[Crofter]

I believe @iSelfBuild used Sioo.

From what I understand it is primarily a method of obatining a uniform silvered appearance, without having to wait for natural weathering; I think it also provides some protection to the wood. Probably not necessary to apply it to unseen faces of the boards.

I did consider it myself but it would have doubled the cost of my cladding, and in any case I actually prefer the fresh sawn colour.

[Nickfromwales]

May be a consideration where sunlight is shaded, eg door and window reveals, and you end up getting an ‘uneven’ look. 

[Roz]

I think I'm quite set on using it, I like the generally lighter grey things seem to weather to when using it too, I'm just not sure whether to buy pots of the stuff and paint it on ourselves or whether to get the factory to do it. Factory costs loads, we could save maybe £500 doing it ourselves, but is it worth it to save us from painting each board with it? I know it needs 3 coats in total which does sound like a pain in the bum. And if there's risk of messing it up we wouldn't want to do that.

[jack]

On 15/09/2018 at 16:24, Nickfromwales said:

May be a consideration where sunlight is shaded, eg door and window reveals, and you end up getting an ‘uneven’ look. 

 

In my experience, it's at least as much about rain as sun. There are parts of our cladding that get plenty of sun but have hardly faded at all because they're protected from the rain. You can see a very uneven/splotchy diagonal line inside the deep reveals that marks where the rain gets to. 

 

When you take overhangs out of the equation, the north side of the house isn't far off being as faded as the south.

[Gone West]

3 hours ago, jack said:

 

In my experience, it's at least as much about rain as sun. There are parts of our cladding that get plenty of sun but have hardly faded at all because they're protected from the rain. You can see a very uneven/splotchy diagonal line inside the deep reveals that marks where the rain gets to. 

 

When you take overhangs out of the equation, the north side of the house isn't far off being as faded as the south.

That's exactly our experience with our cedar cladding. Where the rain blows under the verandah there is a diagonal line of faded cladding below and original colour above. This is the north side before and after with about four years between.

 

 

 

[Jeremy Harris]

We have waney edge untreated larch cladding and the colour variation around the house is amazing.  There are areas under the eaves that are still almost the same reddish orange it was when first fixed, and there are areas, like the East facing wall that have gone very silver.  The sunniest wall, that to the South, is far from being the one that's weathered to grey the most, it still has distinctly reddish orange areas.  The West wall isn't as grey as the East wall, for some reason, which is odd as that wall does see driving rain at times.

 

I agree with @PeterStarck that rain/water has a big impact, as we have some staining from where I originally fitted standard flow guttering, and with our 45 deg pitch, slate roof, with lots of solar panels built in, the rate of rain run off exceeded the gutter capacity, so we have two streaks either side of the central gable where rain water run-off has washed the colour out of the larch.  They are fading away now, as the cladding turns a more uniform grey.

 

I'm not sure whether or not treating the larch initially would have been an improvement or not.  We wanted a very rustic look, as the house is supposed to look a bit like a barn and cart shed that stood on the same site for around 200 years before we built on it, so the colour variation is something we quite like.  We definitely didn't like the colour of the larch when it went on, though, it really was a bit "in your face" red.

[iSelfBuild]

 

2 Years on:

 

 

 

 

Edited January 6, 2020 by iSelfBuild

[Roz]

On 06/01/2020 at 20:52, iSelfBuild said:

 

2 Years on:

 

 

 

 

Hey @iSelfBuild love the meadow! Did you bother to sand the cladding down before applying the sioo - presuming it came planed? I think I read that it is best applied to a sanded finish but I cant remember what grit, and wondering how important it is.

[iSelfBuild]

Hi Roz,

 

I don't think we sanded any of the cladding. We ordered quite a high grade of larch and from memory it was as smooth as a babies behind! I'd suggest you call SIOO directly as I can't remember much about it as it was so long ago. Got to say, we are so happy we applied the coating though and despite it being expensive I think it's worth the money. If the larch had gone black then we would have hated the look of it. Since the site is very damp outside of Summer it makes a real mess of untreated larch on nearby properties.

 

Rich

[Roz]

12 hours ago, iSelfBuild said:

Hi Roz,

 

I don't think we sanded any of the cladding. We ordered quite a high grade of larch and from memory it was as smooth as a babies behind! I'd suggest you call SIOO directly as I can't remember much about it as it was so long ago. Got to say, we are so happy we applied the coating though and despite it being expensive I think it's worth the money. If the larch had gone black then we would have hated the look of it. Since the site is very damp outside of Summer it makes a real mess of untreated larch on nearby properties.

 

Rich

Thanks Rich, thats what I wanted to hear as our cladding is nice and smooth and I don't really want to sand it as its nice, but also don't want to waste the sioo if it wont work unsanded. I think it will be fine! But this is from their website:

"For new timber, the best penetration of the SiOO:X treatment is achieved on a sawn surface. At the very least the surface should be sanded with no finer than an 60 grit paper."

 

Is it normal to have some boards with split ends? I guess I just try and work around it and count it as wastage. This is an example in the middle of the photo - a couple more at the bottom of the photo.

 

Edited February 5, 2020 by Roz

[NickB]

Did you do this yourself Roz? We are also debating this finish with our larch as to whether to go with the sawmill (Thousands £££) of just coat it ourselves. 

[Russell griffiths]

My supplier wanted £1 per m to coat my cedar, I thought this was extortionate until I started doing it myself, it has taken hours and hours and hours. 

So it all depends if your cash poor and time rich or not, I also found the cost of the oil was more than I had bargained for. 

[Roz]

On 25/09/2020 at 15:19, NickB said:

Did you do this yourself Roz? We are also debating this finish with our larch as to whether to go with the sawmill (Thousands £££) of just coat it ourselves. 

I didn't. Our larch is almost finished but we've done it slowly, so some of it has started to silver already . Planning to sioo:x once it's all up. I figured that you're sort of paying to have it done on both sides when you only really need it done on one... so that was my thinking. I know they recommend you do it on all sides, but they also say you can use it to revitalise old cladding / decking, so it's obviously not completely necessary. 

[Roundtuit]

As above,  I Sioo-X'd ours after fitting.  Larch is pretty durable anyway, so I couldn't justify the expense of treating the back and the off-cuts.  Not too bad a job with a hand pressure sprayer from Screwfix and a masonry paintbrush to work it in, but you need to time it right with the weather.

[LeeVanCleef]

We went for Siberian larch factory coated with 'original' (non-pigmented) Sioo:X for the bulk of our cladding. We also ordered a second batch for the eaves / window reveals which was uncoated (bad planning on my part - should have got it all in a one-er) 

 

I agree with the comments above that it seems to be the rain more than the sun that impacts the weathering. We have a few medium sized overhangs and there is a faint diagonal patch where the rain hasn't reached. Having said that it does seem to be getting fainter and I suspect in another few months it will be much more uniform.

 

On OP's original question, if you are going to save a big lump AND can coat it all easily then maybe go for coating it at home. Bear in mind it is a 3 coat system so I wouldn't bank on doing it unless you have a dry space to work in (large shed / garage).

 

I can't remember our cost differential but if I were to do it again I would probably go for all factory coated as coating the few bits I had was a chore. 

 

I would also add that it does look great. I spot other cladding jobs in our area that look a bit pants by comparison (to my eye) and I wonder what combination of timber / coating was used.