Carport Cold Roof - to ventilate or not to ventilate?!?

[Jazzconley]

Hi all! I’m looking for some help.
I have a carport attached to the side of my house. It’s a pitched, cold roof that I’m planning to insulation using 25mm Celotex between the rafters and the plasterboard over the top.
My question is, do I need to ventilate the spaces between the rafters? I’ve seen lots of conflicting information! Any help would be appreciated! Jazz

 

[noseall]

Hi all! I’m looking for some help.
I have a carport attached to the side of my house. It’s a pitched, cold roof that I’m planning to insulation using 25mm Celotex between the rafters and the plasterboard over the top.
My question is, do I need to ventilate the spaces between the rafters? I’ve seen lots of conflicting information! Any help would be appreciated! Jazz

Carports require neither insulation or ventilation.

 

[Jazzconley]

Hi we are insulating as it’s an enclosed carport that’s being used to store a classic car.

My question is in regards to ventilation between the roof and celotex if you have any experience of that?

 

[Jazzconley]

Carports require neither insulation or ventilation.

It’s enclosed and requires insulation to reduce damp (which is currently an issue). I’m storing a classic car in there. What do you think about ventilation between the roof and celotex?

 

[noseall]

It’s enclosed

It's a garage then.

requires insulation to reduce damp (which is currently an issue). I’m storing a classic car in there. What do you think about ventilation between the roof and celotex?

Insulation alone won't prevent (condensation) damp. Ventilation will help. It depends which battle you are trying to fight, really. Is it the garage space you are concerned about or the roof structure?