In areas subject to wildfires burning embers can be blown in through these openings potentially starting roof fires.
Vented vs unvented roof.
When insulating your attic the contractor can either spray the attic floor to keep a vented attic or spray the roof deck for an unvented system.
In an un vented roof foam can serve as the air barrier and vapor retarder and prevent moisture from getting in to the roof cavities.
Control construction moisture content with tenting or temporary roofing when necessary.
That said air resistance and interference such as vent grates reduces the area of true ventilation.
Let s dive a little deeper into what that means exactly.
Vented attic roof designs have the advantage of a long proven historical track record.
In coastal climates wind driven rain can be blown in through these openings with similar results.
Control of ice dams moisture accumulation and heat gain can be successfully addressed by both vented and unvented attic or roof design.
A vented attic system refers specifically to having working vents in the attic.
In this case you can learn a lot from foam tech s article vented vs.
In pitched roof construction thermal insulation can be placed horizontally at ceiling level cold roof.
Unvented roofs which provides a detailed explanation of each.
In other words the entire vent opening doesn t count as vented space.
Vented roofs vented roofs serve a number of different purposes and their roles vary from climate to climate.
Unvented roof assemblies are not prone to these problems because the ventilation openings have been eliminated.
In a vented roof foam can seal the openings and serve as an air barrier and a vapor retarder in addition to its insulating function.
Basically the term cold roof refers to a traditional roof or vented roof while hot roof refers to a roof that is not ventilated and which has foam insulation attached directly to the roof sheathing.
The choice of the venting approach is up to the designer.
Roof vents are for warmer climates.
Too many people believe the importance of roof ventilation is to increase energy efficiency during the summer.