Flat roof - how to add vents in fascia/cladding?

[wilco88]

Hi,

I have a small flat roof that is really in need of a full re-do but we cant afford to do it at the moment.

I have stripped off some of the old rotting fascia/cladding. I will be replacing it in the coming weeks.

We have recently added insulation to the flat roof ceiling space (between joists/rafters) where previously there was none. We made sure to leave room for an air space between underside of roof and insulation.

I want to make sure there is adequate ventilation in the roof so that we dont get condensation/mold issues.

What is the best way to add some kind of vents to the fascia boards?? I am not adding a roof vent through the top.

If there was a soffit space i would add the vents there but there isnt, the fascia/cladding is basically tight to the building (sitting on 3/4 inch battens).

Or maybe the gap created by the 3/4 inch battens would provide adequate ventilation?

I am thinking of some kind of vent strip or louvre, maybe like the circular one in the attached picture?

I know it's a horrible roof/detail but we have to live with it for now!

See pictures attached of the roof.

Any help/ideas would be much appreciated. Thanks!

 

[^woody^]

It does not appear that the roof will be ventilated at the house end. There is little point in adding vents to one end only.

Also, as this roof was not ventilated previously, If there are no problems because of that, why would it need ventilating now?

I would fill the whole lot with insulation no air gaps, seal it back up, and fit a vapour barrier on the ceiling or foil backed boards if you have quilt insulation.

 

[foxhole]

Ventilation of roof space won’t prevent mould or condensation .

 

[datarebal]

Ventilation of roof space won’t prevent mould or condensation .

?