In article ,
N. Thornton wrote:
You might even consider converting this flat roof into a balcony - it
sounds as though the joists are strong enough.

Sounds nice.

I believe the old fashioned quality way of flat roofing was to use zinc
sheet metal, soldered together at the joins.

For a balcony, asphalt might be a better solution. This is what I've got
on my roof terrace which is an addition. I've got 'promenade tiles' on top
of this which are IIRC GRP reinforced concrete. It's all pretty practical
and hardwearing.

I made a zinc tray to replace the rotten one above a bay window, which has
a flat roof. It was pretty easy using my school taught metal working
skills.

--
*Life is hard; then you nap

Dave Plowman London SW 12
RIP Acorn