Flat or pitched roof for extension?

In days gone by it would always be a pitched roof for longevity, but as I understand it (although I have no first-hand experience) flat roof material has improve substantially in recent times.

My rear extension will have a roof 5x5m by 3.9m. My designer (long time ago and now long gone) designed it with a 17.5 degree pitched roof, but I can't help but think that a flat roof with a flat roof skylight in it might be a better option if the quality of lifespan of a flatty is now comparable - and easier for me to fit (as I'm DIY).

I'd welcome people's views on what they'd do if it was their property? Thanks

 

there is no issue these days with flat roofs....provided they are installed properly.

I would recommend EPDM for DIY install. I did a 35 sq metre roof last year on my garden office / cabin -its been great.

dont try and order the roof in one piece -put in a join -its not a risk of leaking done properly and you wont have a hernia trying to lift a 100kg sheet up in one go!

you might want to go on a course for training -rubber4roofs do courses and are based in Coventry

if you are having a flat roof with a skylight -be very careful in working out the falls -its more complex than it looks. With EPDM Id try to get a 1 in 40 fall to avoid ponding at any seams.

 

Pitched all day long

 

What's your rational?

 

It's not rocket science. A good tiled roof will outlast any flat roof. Obviously its more expensive but it will last (If done correctly)

 

For a roof you would tend to make a choice based on design aesthetics or technical criteria, not just on lifespan.

You would struggle to fit a roof lantern to a pitched roof for example.

 

want a bet? i have some pictures some where

 

I only see the point of skylights in very dark areas, big with standard back door.
Usually this skylight business in standard extension is only a waste of money and maintenance as they get dirty very quickly.
That's without counting the fact that in my days I have seen plenty of them leaking as the flushing kit was installed incorrectly.
Do you really need a skylight?
If not, pitched roof is the obvious choice as what you save on skylight will go towards the cost of tiles.

 

Tiled roof & 3 velux skylights with vaulted ceiling.

 

Thanks everyone for your input. Seems like a bit of a mixed view. So hopefully this adds a bit more detail to my situation. Current plans which were drawn up back in 2014 are as follows:



The designer actually didn't incorporate a change I wanted when the plans were submitted - highlighted in orange as I wanted the steels to be at the 1st floor level (sitting on top of another beam that will open up the existing kitchen).

I've decided that I would really like a flat roof at the front of the house as there's currently a flat roof there now and other houses with a pitched front roof look a bit off. Basically I'm trying to copy this look, but with a front roof that extends along the blue line:




However the rear roof is where there's a few options:

(I don't have a CAD programme, so I doctored the original image using powerpoint - so sorry it's a bit rubbish)



So the above has one of those flat skylights in it, and allows the kitchen sealing to be one level.



I suppose with the latter I could lose the badly drawn Velux, but with the bedroom above sticking into the kitchen roof it looks a bit odd.

I know they all look a bit rubbish in cross sectional view.

One of my neighbours already has a similar extension with no skylight (nor rear window) and I think it's not the prettiest thing - like a wall of tiles - looks like a steeper pitch than the original design of mine.



Thanks everyone for your input.

 

the neighbours would have looked nicer if they had stuck with the tiles used on the rest of the building. wesssex rather than renowns

 

Wessex? Yuck. Hideous tiles - but essential.
It would have looked nicer if they had mimicked the pitch of the main roof.

​

 

I hadn’t realised the neighbour had used different tiles?

@noseall what’s wrong with the Wessex? I was planning on replacing my roof with Wessex as that’s what was there before. Thanks

 

And used Wessex Agree not the prettiest but serve their purpose..still better than the renowns

 

Wessex won't win any beauty competitions, that's for sure. They aren't the cheapest either nor are they much fun to work with/on. They are designed for low pitch situations so are essential for those roofs with very shallow pitches.