Workshop open joint cladding

[pike]

I'm going to convert my 10x10 shed into a 20x10 workshop this year hopefully. I'd really like to use open joint cladding (just regular timber boards with gaps of around 10mm) fixed vertically.

Can anyone suggest what I'd have to put behind them (other than battens) in order to keep things waterproof and uv protected? Things I've considered so far: Roof EDPM (costly and can I fix battens through it?), tyvek uv facade (expensive but apparently exactly what it's designed for) or osb/ply with some sort preferably black waterproof treatment (cheaper).

Will osb/ply work well enough? I just don't quite understand how having osb/ply on the outside will work as far as allowing the wall and insulation to dry out as per Mr Garnhams shed guidance. In previous builds I've done ply on the inside, insulation, building paper, battens then cladding. If I put osb/ply externally will I have problems with the inside of the wall not getting any air?

Cheers!

 

[blackrodd]

If you mean close boarding as in yorkshire boarding, and fixed to another background, I don't see why you need to do this as keeping the rainwater from laying and therefore rotting out would be difficult.
This boarding was initially for sheds housing farm animals and generally on the top 1/3rd of a wall.
Should you be matching existing, then bevel all angles to throw water off and build the wall from stud, clad in a good grade ply and plant the boarding on the front.
I personally paint with a good quality such as Dulux and try and keep away from any water based stains etc, as i see this stuff every day needing two coats a year to do some protecting.
Please excuse me if I have totally misunderstood you're query.
Regards Rodders

 

[pike]

Thanks Rodders, just googled yorkshire boarding and yes I think that's basically it. Vertical cladding with gaps. From what you say good grade ply on the framing, battens then the vertical boards would do. Are you saying paint just the boards? I was thinking I'd also need to somehow waterproof the ply for any rain that gets between the gaps.

 

[RobinBHM]

I would use OSB3 for boarding,for membrane: tyvek housewrap or chromar vent 3 which is a more budget option, tile battens and then the cladding.

I think the correct detailing for vertical boarding on houses, is to fix vertical battens at 600mm centres, then counter battens horizontally, these battens have a 15 degree water shed angle to the top. The vertical battens are fitted so the cavity formed is vented (at the bottom and closed with insect mesh).

 

[pike]

Robin thanks, especially for the idea of vertical then horizontal battens. That makes a lot of sense for airflow.

I'm not clear what the housewrap is doing assuming it sits directly on the OSB? I suppose it's just additional waterproofing. I assume the breathability of it is irrelevant if on OSB. My previous builds have had the vapour barrier on the inside of the framing, then breather membrane on the outside of the framing/insulation. If OSB is a vapour barrier then whats the point in housewrap on top of it?

Aesthetically, I want the 5-10mm gaps between the vertical boards to reveal nothing but black, so I'd either need breather membrane which was unmarked, black and uv resistant, or just not use that and paint the OSB black.

 

[blackrodd]

Yorkshire boarding, I'm glad I got that right!.
If you get treated 4"x 1", or 6"x 1" board, after a few months you can paint the boards as the preservative has
dried and is stable.
As It seems that Robin knows what he is talking about then Google and confirm the counter battening and off you go!
As a belt and braces measure treated douglas fir ply is available treated also with preserver.
Its available through farmers supply and feed type stores, we have mole valley farmers, down here in sunny Devon.
I always have concerns with using any water based preserver for outside, as it needs twice as much maintainance
compared to the usual oil or solvent finishes, 'Though others may disagree, here.
Based on having worked on the same buildings over 15, or so years, all the water based don't seem to be very durable or tough.
HTH Regards Rodders

 

[pike]

Thanks Rodders,

I've never waited before painting treated wood.. :roll: Seems to have worked out ok so far. Perhaps the wood Ive used has been sitting around long enough already.