Flat Roof Ventilation

[gooseacre]

I am replacing the flat roof of my garage whilst converting it into a dining room - I am also raising the roof a fit to give a better ceiling height in the dining room.

My building inspector has just been round and said that I need a "fillet" vent to allow ventilation through the roof void (between the beams). This means creating an upstand where the roof joins the wall, including the fillet vent and leading over this. This clearly adds quite a lot of cost.

Does anyone know if this is a regulation that must be adhered to or whether it is just a recommendation. I will ask my inspector but wanted to get other opinions before I go back to him.

I have contacted several roofing contractors and they all say it is an unusual request. Builders merchants don't even know what I am going on about!!

 

[noseall]

you could always convert to a warm deck.

big bucks though.......£££££££££££££.

 

[oddballodd]

When converting my flat roof garage into a room I also had to do this to comply with regs. They required at least 50mm clear space between the insulation and the flat roof. To achieve this you need cross ventilation from the front to back or side to side depending on the direction of the joists.

See here for details on the types of vents availiable, but they generally mean that the felt needs to be replaced.

http://www.ubbink.co.uk/roof_vent/flat/felt/fascia_vent.asp

alternativly you can add mushroom vents at the back, but they do look quite ugly.