Sloped ceiling cc 120, do I need to add more studs for OSB+gypsum

[Vinsdman]

Hello, I am in the process of remodeling an attic loft. I am planning to attach OSB + gypsum directly against the vapor barrier/glulam beams with cc 120 (see attached image).

The OSB boards I am considering are Byggmax 11X2440X900mm.

How much rigidity does an OSB provide? Is there a risk that it will flex and cause cracks in the surface layer?
If so, should I install 45x45 cross battens between the glulam beams? If so, is cc90 sufficient or should I install cc45?

 

[Hubbe2]

For plasterboard in the ceiling, cc 30 is recommended. Lay 45x70 across the roof trusses on top.

 

[Vinsdman]

Does the same apply to osb as to plaster?

 

[xyle]

The biggest problem as I see it is that you will puncture the vapor barrier when you screw in the drywall. Also, it becomes cheaper to use glesa than to use osb?

 

[anders07]

At least 45cc with OSB+gypsum but the recommended is 30cc.
45x45 becomes too weak between 120. I would say at least 70 mm.

 

[Vinsdman]

I've been thinking about the vapor barrier and will sacrifice some space for a safer construction. What do you think about installing 29x70 slat panel across the rafters? If so, is there any advantage to cc30 compared to cc45?

 

[Larsa]

28x70 cc 30 I would have driven..

 

[Hubbe2]

The advantage is to space with a measure that suits well for the plasterboard you plan to install.

 

[Direktörpelle]

28x70, cc45 for OSB/gypsum.
28x70 cc30 for single gypsum.