Non Ventilated Roof

Air permeable insulation such as fiberglass batts dense packed cellulose or blown.

Non ventilated roof.

Continuous or individual soffits. A properly insulated ventilated roof can help to control or prevent the formation of ice dams. Because the sheathing is kept cooler roofing materials tend to have a longer life span. I have roof vents so i have roof ventilation.

Preventing moisture is essential for having a properly functioning un vented roof. One static vent style is the turbine vent which uses wind to power its enclosed fan all it takes is a light breeze to rotate the blades and suck heat out of the attic view example on the home. 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. If you plan to insulate a sloped roof you need to decide if you want a vented or an unvented assembly.

For air impermeable insulation verify that the installed insulation is the correct thickness to meet the r value requirement called out on the plans. They are easy to install under the roof s overhang which is known as the soffit are generally hidden from sight and provide excellent protection from weather outdoor debris and pests while still allowing air to flow into the attic. Verify that roof insulation installed under the roof sheathing is well supported and in substantial contact with the sheathing if fiberglass batt insulation. Ventilated roofs remove moisture from roof cavities structural members sheathing and insulation.

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. Take for example ridge vents. The enclosed void of a warm pitched roof does not require to be ventilated. Soffit vents are one of the most popular intake vent styles.

While hardly anybody agrees on the best roof ventilation system everybody agrees some roof vents do hardly any good at all. Vent the roof deck. By martin holladay issue 256 dec 2015 jan 2016. 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.

An unvented assembly can perform well but it s important to get the details right to avoid sheathing rot.