Oak garage breather membrane/ insulation

[Dan1983]

Afternoon all,

Wonder if anyone can advise please.

Touched on this subject before but now started to order materials.

Our Oak frame timber clad garage has no membrane at present.

I would like to insulate and board it to retain some heat in the winter if needed via oil filled rads.

 

Plan is a breather membrane essentially cut into the channels hard up against the cladding where green markings show below.

Thinking is most of the moisture can then still run out of the bottom if required.

There will then be an approx 40mm air gap (thickness of the timber uprights) then 50mm celotex insulation with plasterboard already attached.

 

I know cutting the membrane to fit will be a pain (wish they had added before cladding) but is this the best way vs having it hard up against the celotex backing?

 

Thanks for any pointers 

[Iceverge]

 

 

This would be much easier to build. Tape the PIR at the warm side and you'll have a warm shed. 

[Dan1983]

Ok thank you, didn’t know if I needed the breather membrane directly on the cladding to stop any rain/ wind getting  blown through etc?

 

Looking to get it plastered then painted after.

[Iceverge]

The vertical timbers in your pictures are only to hold up the cladding, much like battens over a stick frame building. It's normal for the breather membrane to be inside these as it allows the back of the caldding to dry into a ventilated cavity. 

 

If you push a membrane tight up against the back of the cladding you'll risk trapping moisture there. 

 

[Dan1983]

Excellent thanks for the diagram 

Will make things much easier 

Will go over the battens with the membrane then celotex straight on top