Is a flat roof (terrace) a terrible idea?

[MisterBoy]

We have on old (100yr+) 2 storey extension on our house, about 6x4m. Original slate roof is in need of repairs.

I was noticing how it catches the evening sun - we lose it around 5-6 everywhere outside - and thinking how a little roof patio could be rather nice.

But I've been brought up told by everyone who ever had an opinion that flat roofs are to be avoided.
What do you pros thing about them? Are they a bad idea or are they fine if done properly?

 

[freddiemercurystwin]

I wonder what type of roofs they've been building on all those buildings without pitched roofs.

 

[diy_fun_uk]

We have on old (100yr+) 2 storey extension on our house, about 6x4m. Original slate roof is in need of repairs.

I was noticing how it catches the evening sun - we lose it around 5-6 everywhere outside - and thinking how a little roof patio could be rather nice.

But I've been brought up told by everyone who ever had an opinion that flat roofs are to be avoided.
What do you pros thing about them? Are they a bad idea or are they fine if done properly?

Like most things, if properly constructed, installed and maintained there shouldn't be any problems.

 

[MisterBoy]

I wonder what type of roofs they've been building on all those buildings without pitched roofs.

Leaky roofs in my experience and everyone I know who has had one Which is why I ask... Put it another way would you buy a house with a flat roof extension or put one on your own house?

 

[freddiemercurystwin]

Not even worth replying to, one of those joke threads.

 

[MisterBoy]

Not even worth replying to, one of those joke threads.

Nope. Not sure why you'd think that. Surely you're aware that flat roofs have a bad rep in the UK. If you don't think it's worth replying to then please don't.

 

[freddiemercurystwin]

Yes they had a bad rep in about 1980, now it's just old fashioned out dated way of thinking. Seriously, do you really think that every house in the UK that has a bit of flat roof on a dormer, extension or garage or whatever is about to cave in or spring a leak?

 

[oldbutnotdead]

Flat rooves are ok, there are many well-established systems that will give you a waterproof roof for 30 years.
Flat roof patios are a whole other ballgame.
First you will need planning permission (platform greater than 300mm above ground level).
If in the unlikely event you are granted permission, you'll have to put beefy rafters in the roof to support the very high imposed load of a number of people.
You'll then need properly constructed safety barriers round the perimeter to prevent people falling off the edge.
You might need additional means of escape (not sure about that tbh)
You'll need a high traffic roof covering (forget felt or rubber, GRP would work but has its own problems) or a superstructure on top of the roof.
And last you'll presumably be losing a bedroom or bathroom to access the thing (unless you're lucky with the 1st floor layout).
Not a job for DIY design...