Hi
My sister has a barn like structure adjacent to and part of her house. Its around 22' long, 9' wide, 24' tall and open on three sides. The construction is of heavy (oak?) beams with a pitched slate roof all in sound condition.
Its not an old building, just made to look old. Not been up more that 15 years.
Previous owners have put in a mezzanine floor - constructed of 9mm ply on 2 x 2 battens at 4' centres - needless to say I haven't walked on it!
Her plan is to clad it on the three open sides, replace the floor, install stairs and an up & over garage door.
The planned use is as a garage/workshop below and a storage and craft area above . It wouldn't be a 'habitable room' up above. Apparently no planning issues involved.
My main concern is that the upper area could be a death trap in case of fire. The only escape would be through the garage area. I think I would need to install a MOE roof window?
Her plan is to insulate the walls & roof and line the inside with 6mm ply. I've advised against this, again on fire grounds - I reckon plasterboard would be safer.
Assuming I can overcome the fire hazard, would 6 x 2 joists at 16" centres over a 10' span be sufficient for the floor? I also assume that the underside of the floor should be insulated & plaster boarded?