Vaulted ceiling - Air gap

[richo106]

I have made a start today on my vaulted ceilings and was just having a browse on the internet.

 

The roofer has used rubershield pro on my roof

https://www.ikogroup.co.uk/product/iko-rubershield-pro/

 

As this is a permeable membrane do I still need to leave a 50mm air gap? Or have a misunderstood this?

 

Kind Regards

[nod]

Yes

[trialuser]

I'm wondering about this as well, but using tyvek supro. As I read it, the BBA cert says you dont need eaves and ridge ventillation, as does one of the FAQ's.

But, experienced people like Nod, often seem to say the opposite?

Still unsure

[richo106]

20 minutes ago, trialuser said:

I'm wondering about this as well, but using tyvek supro. As I read it, the BBA cert says you dont need eaves and ridge ventillation, as does one of the FAQ's.

But, experienced people like Nod, often seem to say the opposite?

Still unsure

My thoughts exactly

[Temp]

Either way you should not press the membrane against the underside of tile battens as dirt and water can collect above the batten causing it to rot.

[Iceverge]

It's approved for unventilated roof construction. 

 

However like @Temp says there is a risk of trapping moisture against the back of the tiling battens. This can be overcome with counterbattens above the membrane but if your tiles are on you don't have this option. 

 

 

 

 

 

 

 

If the roof covering is on then you're in this position an you'll need ventilation below the membrane. 

 

https://www.ikogroup.co.uk/wp-content/uploads/2022/11/IKO-Breathable-Membrane-A5-Nov22.pdf

 

 

 

 

 

 

Edited April 25, 2023 by Iceverge