On most flat roofs however stack effect will be ruled out since all vent openings will be at approximately the same level and there will generally be only small pressure differences from wind.
Venting a cold flat roof.
That means the rest of the roof is protected from heat.
Ventilating a flat roof on a warm flat roof the layer is installed underneath the insulation to stop moisture interacting with it through.
Why don t cold roofs need to be ventilated.
Their layer of insulation is beneath the roof decking and the roofing membranes.
On the unventilated side there is no overhang just a solid facia board flush with the wall.
I have a cold flat roof ventilated by soffit vents on one side and no ventilation on the other side.
Air flow between vents will also be affected by the resistance to lateral flow.
For cold flat roofs the vapour layer needs to be positioned underneath the insulation layer on top of the room below.