Hello!
I have a garage that is 4x8 meters. The roof has a low slope (a few degrees) over the length of the garage. The garage has roof joists (45x170) spanning the short sides at cc60.
Now, I'm going to remove the top layers of the roof and build an air gap and lay down tongue and groove boards. When building the air gap, I plan to lay battens along the entire length of the garage, across the roof joists.
The plan was to lay the battens at cc60 and use 45x45. But maybe that's too weak? The surface covering will be felt, so there aren't any direct weights to consider. It's mainly about making it stiff enough so that stepping or snow load doesn't bend the battens and damage the felt.
Should I go up to 2"-3 or even 2"-4?
Beyond the practical aspects, there is also the aesthetic. If I leave visible battens in the eaves, is thicker always better?
I have a garage that is 4x8 meters. The roof has a low slope (a few degrees) over the length of the garage. The garage has roof joists (45x170) spanning the short sides at cc60.
Now, I'm going to remove the top layers of the roof and build an air gap and lay down tongue and groove boards. When building the air gap, I plan to lay battens along the entire length of the garage, across the roof joists.
The plan was to lay the battens at cc60 and use 45x45. But maybe that's too weak? The surface covering will be felt, so there aren't any direct weights to consider. It's mainly about making it stiff enough so that stepping or snow load doesn't bend the battens and damage the felt.
Should I go up to 2"-3 or even 2"-4?
Beyond the practical aspects, there is also the aesthetic. If I leave visible battens in the eaves, is thicker always better?
I would probably have put a windbreak directly on the rafters....then a 28x70 on each rafter and then rough paneling on that...
Scattered advice 
Rafters on cc60, then there are additional crossed battens on top, also cc60. The reason I'm not placing the battens in the air gap along the rafters is that the ventilation would then go the wrong way and trap condensation and moisture that wants to flow along the roof's slope.
Matti_75: Go up to 2"-3 anyway?
Rafters on cc60, then there are additional crossed battens on top, also cc60. The reason I'm not placing the battens in the air gap along the rafters is that the ventilation would then go the wrong way and trap condensation and moisture that wants to flow along the roof's slope.
Matti_75: Go up to 2"-3 anyway?