There are lots of ways to insulate a low slope roof and most of them are wrong.
Low slope roof ventilation problems.
Flat and low slope roof designs to avoid moisture condensation problems flat roofs call up a whole new breed of building moisture problems how to avoid moisture traps under flat roofs avoid mold rot caused by moisture trapped under un vented flat roofs questions answers about the cause cure prevention of moisture problems in flat roofs and similarly hard to ventilate structures.
The roof is 14 4 2 meters wide but the drip edge came in 10 3 meter segments.
When it comes to low slope roof systems the old adage that an ounce of prevention is worth a pound of cure truly applies.
In the case of low slope roofs builders and roofers not only need to solve the ventilation problems but they also have to make sure that there are no leaks caused by the air vents.
Some of the most common low slope roof problems relate to improper installation or lack of maintenance.
For flat roofs or low sloped roofs with pitches of less than 1 6 such as cathedral ceilings the total net vent area should be at least twice as large or 1.
A lot of roofing contractors in the area could just provide you with a band aid solution using mostly a caulking mixture to cover up the leaks and this will certainly not last long.
So two segments were installed overlapping by 6.
These vents can be located in the soffits in gable walls in the roof surface or at several of these locations but should be distributed so as to provide effective cross ventilation.
Secondly you really have two different roof types working here low slope or flat roofs and pitched roofs.
Using v2t vents the vent secured system creates a suction effect that strengthens the entire roof and holds the membrane securely in place.
I have seen ventilated flat roofs but they are usually used in conjunction with attic spaces and you mentioned finished vaulted ceilings in your post.
Resilient synthetic rubber membrane widely used on low slope roofing projects for over 50 years in the united states and worldwide.
For ventilation channels to be effective you need a slope of at least 3 12 or steeper.
In older buildings the usual method is to install fiberglass batts or cellulose on top of the leaky ceiling with a gap of a few inches or sometimes a few feet between the top of the insulation and the roof sheathing.
There is a clear answer to your question.
The problem with that was that with the slope as low as it was the doubled up drip edge made for enough of a ridge that the shingles sloped back a little forming a trough for water to accumulate in.
Basically you need lots of height above the top of your insulation layer plus a few vented doghouses cupolas.
Updated on april 8 2016.