Steel box profile, membrane?

[couchie]

Hi All

Im going to re clad my inlaws garden room with steel box profile roofing. At the moment it's aspestos cement sheets. Which are failing & sagging. I intend to reframe the roof before I put any more load on it. The roof is about 5.5mtrs x 8mtrs.

There is a interior ceiling then about a 4' roof space. Do I need to put a membrane down before I sheet up?


Thanks.
Regards, Chris.

 

[smashngrab]

Why not buy the sheeting with anti condensation backing on it.

 

[couchie]

Thanks for the idea

I would if I was buying it new, but it's left over from a job so I'm getting it cheap.

But I take it from your answer I do need some type of barrier, there are so many types out there I'm finding it confuseing. Can anyone point me towards what I need, something good enougth but doesn't have to be the Rolls Royce of membranes.

Thanks
Chris.

 

[smashngrab]

If you used a breathable under slaters felt i think you would have to counter batten it. This would keep it away from touching the underside of the sheeting.

 

[couchie]

I'm going to batten the joists before I fit the sheets, I suppose I just roll out the membrane first.

 

[smashngrab]

Yes, felt on first then the battens.