Warm Roof Not Possible Due to Low Windowsills -Help!

[Jillofmosttrades]

Hi Folks,

I have a peculiar issue.

I have a flat roof over what is about to become a kitchen dining room. The roof is not in terrible shape - I would say in the normal state of things it had maybe 3-5 years left on its life, however, as we are renewing the kitchen we would like to put a roof light in, so it would seem sensible to renew the roof at the same time.

I am aware of the building regs requiring upgrade of the roof to warm roof construction, but this is just not possible due to the windows of the floor above being very close to the top of the extension roof (pics).

What would all the roofers out there recommend in this circumstance?

Is there some magic that can be done at sill abutments to make it waterproof without the standard flashings?

If I have to leave it as a cold roof construction there are noggins half way down the structure which would make it not possible to have airflow all the way above. (Pic -the ceiling is down at the moment so it’s possible to see) any advice on this?

I have also heard that fibreglass rooves over kitchens are perhaps not the most sensible if it’s a cold roof construction, and although this sounds unfounded to me I’d be interested in any opinion?

Thanks for your input guys!

 

[noseall]

I'd bet a clever builder could build and weather a warm roof there, once those crappy sills have been chopped off (along with that hideous render) and replaced with some clever lead flashings. There looks to be a decent depth betwixt the exiting roof and the bottom of the window.

 

[Notch7]

Maybe 8 x 2 joists, set down a tad lower.

50mm celetex over joists, maybe 100mm in between.

18mm deck, grp

If that doesnt work, why not get 2 new windows a bit shorter.

 

[^woody^]

I am aware of the building regs requiring upgrade of the roof to warm roof construction

No such requirement.

The requirement to improve insulation can be met by insulating the roof completely with no air gaps and no drama.