Flat Roof Non Venting Methods

For cold flat roofs the vapour layer needs to be positioned underneath the insulation layer on top of the room below to create an effective barrier.

Flat roof non venting methods.

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 intent of roof venting varies depending on climate but it is the same if you re venting the entire attic or if you re venting only the roof deck. Specialized roof coatings are available in a wide range of materials and can help a flat roof reflect up to 90 percent of solar heat. Unvented roofs which provides a detailed explanation of each.

Un vented roofs operate on the principle that moisture entering the roof assembly can be controlled and that there is no need for venting to control moisture accumulation. On a warm flat roof the layer is installed underneath the insulation to stop moisture interacting with it through rising thermal pressure lower down in the building. In a cold climate the primary purpose of ventilation is to maintain a cold roof temperature to avoid ice dams created by melting snow and to vent any moisture that moves from the conditioned. 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.

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. In this case you can learn a lot from foam tech s article vented vs.