Workshop cladding - prep & oiling advice

[BucksDad]

I have got to the stage with my workshop where the cladding is going on - unfortunately my wife picked board-on-board cladding which, being my first ever cladding project, I've discovered is a right pain because you're effectively cladding the walls twice!

I nearly have the bottom layer done so I figured I should oil those before the top layer goes on with shrinkage etc.

Couple of questions - Siberian Larch cladding

1. Should I sand the cladding first before applying the oil/UV protection - some of the boards seem to be a little rough but does that matter?

2. Which oil/UV protection do people recommend these days?

We would like a matt finish with no tinting (i.e. clear finish). And yes, I know I have to re-apply it every 2 years but that's not a problem

 

[Molynoox]

I have got to the stage with my workshop where the cladding is going on - unfortunately my wife picked board-on-board cladding which, being my first ever cladding project, I've discovered is a right pain because you're effectively cladding the walls twice!

I nearly have the bottom layer done so I figured I should oil those before the top layer goes on with shrinkage etc.

Couple of questions - Siberian Larch cladding

1. Should I sand the cladding first before applying the oil/UV protection - some of the boards seem to be a little rough but does that matter?

2. Which oil/UV protection do people recommend these days?

We would like a matt finish with no tinting (i.e. clear finish). And yes, I know I have to re-apply it every 2 years but that's not a problem

I've heard lots of differing advice on this one. I sanded mine and then oiled. If the wood is planed the sanding can help prepare for sealing, if it isn't planed I'm not sure it's important.

The one thing I did learn is to oil the wood immediately and don't let it get wet. If it's wet let it dry out before oiling otherwise the water staining gets locked in. I plan to sand mine back in the summer and re-oil as there is still some mild water staying that bugs me.

Martin

 

[BucksDad]

Thanks Martin for the tips. I was looking at the Owatrol products as they generally seem to be the most highly rated ones. However Owatrol say not to oil new timber but put their other product on first - Seasonite and then wait 6-12 months before oiling

Knowing you're one who researched everything for your build, did you look into that and not bother or ?

 

[Molynoox]

That's interesting - I didn't know that about the textrol stuff, to apply the seasonite first

I think with oil it was probably the one thing I didn't research all that much... at the time the whole world was on the osmo bandwagon and it seemed like a no brainer. I think now though, there are some competitor products that are becoming more well know, eg textrol HES.

I'll probably do a bunch of research on it sometime soon but for now I don't know much at all

Martin

 

[Glitch]

I clad by shed and BBQ shelter in Siberian Larch - V-joint weatherboard.
I sanded it and treated it with Sansin SDF before fixing. Expensive but so easy to use, goes a long way and a great range of finishes.

https://www.silvatimber.co.uk/sansin-sdf-for-cladding-fencing-decking
Edit: Added a second coat after fixing.

 

[Jones]

If it's rough sawn it's worth sanding to remove any hairiness which will reduce the amount of finish you need. Make sure you get the nailing right for board on board cladding. The nails for the top boards will need to be longer than for the first layer boards and they should not go through the first board but just skim it and fix into the batten.

 

[MikeJhn]

Have not read every post, but do use ring shanked SS nails and drop a plumb bob down to line them up, use a spirit level to line them horizontally, nothing worse then rusty out of line row of nails.

 

[BucksDad]

I've used SS screws so far and all screws are aligned horizontally and vertically and I have made a jig for vertical alignment of boards, correct spacing etc.

For board-on-board, why should the top board screw into the batten rather than the bottom layer of boards?

 

[Fitzroy]

I've used SS screws so far and all screws are aligned horizontally and vertically and I have made a jig for vertical alignment of boards, correct spacing etc.

For board-on-board, why should the top board screw into the batten rather than the bottom layer of boards?

With any cladding you are ideally trying to avoid two fixed points across the board width, else you risk splitting with seasonal wood movement.

 

[BucksDad]

With any cladding you are ideally trying to avoid two fixed points across the board width, else you risk splitting with seasonal wood movement.

Hmm I do remember reading about this but kind of put it to the back of my mind as something only applicable to feather edge
This my first time doing anything like this and I have fixed two screws on each side of the first layer of boards... ARGH. Oh well, too late to change it now!

 

[Jones]

Two fixings per board is ok, but you should put the fixings in a bit from the edge on the top board so the boards are not fixed together and can move relative to each other. Ideally the fixings in the first board are covered by the second board as that looks neat.

 

[BucksDad]

Two fixings per board is ok, but you should put the fixings in a bit from the edge on the top board so the boards are not fixed together and can move relative to each other. Ideally the fixings in the first board are covered by the second board as that looks neat.

Yes this is how it will be. I have two fixings close to edge on each of the lower boards. These fixings will be covered by the top board. I have a thick /thin BoB style so only a 20mm gap between the lower boards.

I'll put one fixing in that gap for the top boards and hopefully any splits are covered by the top one

 

[Fitzroy]

Hmm I do remember reading about this but kind of put it to the back of my mind as something only applicable to feather edge
This my first time doing anything like this and I have fixed two screws on each side of the first layer of boards... ARGH. Oh well, too late to change it now!

It's why I use the word 'ideally', I've gone against many of these ideals and most of the time there has been no negative outcome. But if you are a builder and build dozens of buildings a failure one one of them will tarnish your whole recommendation, so you'd want to stick to those ideals.

 

[BucksDad]

It's why I use the word 'ideally', I've gone against many of these ideals and most of the time there has been no negative outcome. But if you are a builder and build dozens of buildings a failure one one of them will tarnish your whole recommendation, so you'd want to stick to those ideals.

Thanks. It's why I decided to go with the knowledge I've already gleaned, check a few things but just carry on and not post frequent updates. I think you can end up with too many opinions & options and I would end up fretting unnecessarily. Online you can see how there's plenty of opinions even amongst builders / trade professionals on the right way to do something.
When I update my build thread with the finished result, I guess I will find out what I've done wrong