On flat roofs with soffit vents the only mechanism that might drive air thorough the vented space would be occasional wind conditions that happen to blow air against one side of the building and up through the soffit vents across the roof to outlet on the opposite side a rather speculative roof venting system you ll probably agree.
Venting flat roof space.
The typical flat or near flat roof with no intentional air space is used mainly for commercial and industrial buildings.
If the attic space is going to be conditioned either for living or mechanical purposes or if a home design calls for a vaulted ceiling provision r806 3 in the international residential code calls for the roof deck above the space to be vented continuously from the eave to the ridge.
How much ventilation does a flat roof need.
Choosing the correct ventilation solution for a flat roof will play an integral role in extending a structure s lifespan.
Vent the roof deck.
This is easy to accomplish in simply.
This is easy to accomplish in simply.
The answer depends on the type of roof you have.
Consequently the article concludes that the concept of venting a flat roof is no longer safe and instead don t vent the flat roof and install a smart vapor retarder inboard.
Ventsure 4 foot strip heat moisture ridge vent with weather protector moisture barrier.
To understand ventilation in roofs we must first recognise that there are many different roofs types.
27 lineal feet required.
If the attic space is going to be conditioned either for living or mechanical purposes or if a home design calls for a vaulted ceiling provision r806 3 in the international residential code calls for the roof deck above the space to be vented continuously from the eave to the ridge.
It s unavoidable that the thermal temperature in the roof space will bear the brunt of the heat generated in the living spaces below.
The article notes that the ventilation cannot overcome the significant humidity drive into the flat roof structure caused by small air leaks.
It depends on where the insulation is installed.
In ireland the most common types are pitched lean to and flat roof construction.
Hot roofs have the roof deck then insulation then the roofing material.
Venting of flat roofs.
Ventsure 4 foot strip heat moisture ridge vent.
Originally published may 1976.
It is the principal concern of this digest for it is often plagued by moisture problems.
Choose one of the following products to meet the recommended exhaust nfva of 528 square inches.
Each of these roof types poses different challenges for ventilating a roof space.
A cold roof or hot roof.