Hot And Vented Roof

Also see insulation location for cathedral ceilings for more information.

Hot and vented roof. In hot climates the roof temperature will be much higher on an un vented roof resulting in much shorter shingle life. The hotter an attic is the more expensive it is to cool the upstairs of a home. Most studies show anywhere from 1 to 5 maximum increase in surface temperature during the sunniest part of the day while at night the surface temperature drops faster than a regularly vented roof. In a hot climate the primary purpose of ventilation is to expel solar heated hot air from the attic or roof to reduce the building s cooling load and to relieve the strain on air conditioning systems.

A secondary goal is to vent moisture that infiltrates the attic from the conditioned home. This can easily create attic temperatures as high as 125 f. In colder climates the main purpose of a vented roof is to keep the roof cold and reduce the formation of ice dams. A hot roof over a poorly vented attic translates into a very hot attic.

The theory behind a hot roof system is that rather than allowing heat to escape through your roof you contain it in your attic space which can save on utility costs in theory. In mixed climates ventilation serves either role depending on the season. 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. Roof vents are for warmer climates too many people believe the importance of roof ventilation is to increase energy efficiency during the summer.

Intake vents located at the lowest part of the roof under. When the temperature outside rises the temperature on your roof can be nearly double. Vented roofs serve a number of different purposes and their roles vary from climate to climate. Unfortunately the term hot roof is a misnomer as the roof really is not that much hotter than a normal roof.

Ventilation benefits a roof when it s hot outside as well. Cool air in hot air out attic ventilation works on the principle that heated air naturally rises primarily utilizing two types of vents. Good roof ventilation can do this but shingle color sun exposure and insulation are exponentially more important to overall energy efficiency than ventilation.