Hey all.
My situation is similiar to those of others but I still haven't found a definitive answer (if there is one!)
Basically i'm going to buy a house with a garage that I will be converting into a studio by building a room within a room. As I don't own the house yet I cannot get any pics unfortunately but I will explain thoroughly what I am dealing with.
The garage is brick built and I am going to block up the window and big door leaving a normal door for access. I want to seal the whole construction and then build a room within a room but the ceiling seems to be my major weak point. It is a pitched roof with some sort of corrugated plastic or asbestos
on top. Ideally, I would like to be able to insulate and drywall to the underside of the rafters, sealing everything to the existing walls so that the outer room is airtight. Then I would build the internal room, sealing everything.
My problem is that this would appear to create a triple leaf, consisting of 2 layers of drywall on my inner room ceiling, air space, drywall on the underside of rafters, air space, corrugated sheet roof. After spending time and money sealing the outer building construction, it seems a shame to then not be able to add drywall under the rafters to avoid this triple leaf as the ventilation from the eaves would render the construction non-airtight!
I understand that this is one of those things and that i just have to work with i have, but what is the trade off between the triple leaf and the leakage through ventilation?
My question basically, is am i better to create a triple leaf but have an airtight room within an airtight room, or should i avoid the triple leaf and have an airtight room within a non-airtight room?
Thanks for the replies peeps
