Roof Vents For Flat Membrane Roofs

Collar height square flange and an inner louver wildlife guard.

Roof vents for flat membrane roofs.

The keepa attic vent is typically used for ventilating attics and or plenums as a roof exhaust vent or as an air intake roof vent. When thermal insulation is placed below the deck the ventilation must also be on the underside. What is flat roof ventilation. There are two types of flat roof systems warm and cold roofs which affect the positioning of the ventilation.

We also cover spray applied foam and liquid roofing options. This is why the vertical height of the vents for flat roof ventilation needs to be at least 8 inches high. Flat roof ventilation is a niche that active ventilation products avp has supported and supplied for many years. Avp s flat roof vents are manufactured specifically for flat roof ventilation.

The short answer is. Common flat roof membranes discussed in this article include built up asphalt tar and gravel modified bitumen and single ply membranes like epdm pvc tpo and kee. A tough reinforced double layer membrane system should not be affected by interstitial moisture. In particular a warm roof system tends to be the ultimate protection from flat roof moisture concerns.

Unvented flat roofs a technical discussion flat roofs have often been built with the insulation all on top of the vapor closed drainage plane as this avoids dew point condensation issues inboard of the roofing. No ventilation is required with flat roofs when the right membrane is used and installed correctly. Roof vents need to be built tall for flat roofs because flat roofs drain water poorly and slowly compared to steep sloped roofs. Attic vents relieve humidity during the winter and heat during the summer to help extend roof membrane life.

An airspace is left above the ceiling insulation and below the under side of the roof decking and the roof is vented either around its perimeter with soffit vents a flat roof or the roof may be include intake venting at its lower edge through a soffit and outlet venting through a half ridge vent or similar outlet vent along the roof s uppermost edge a low sloped roof. All flat roof vents including air intake vents and air exhaust vents are used together for balanced roof top ventilation. In addition such vents will relieve vapour pressure generated under a heated roof surface and this will help in relation to some types of membrane blistering. Flat roof ventilation allows for the circulation of air in the property particularly for warmer rooms in residential buildings.

The keepa attic vent is built solely for flat roof ventilation a roof pitch that is 2 12 or less. For insulating fills placed over cast in place structural concrete decks box vents are usually advisable to provide for drying of wet fill even if there is no vapour barrier. This slow drainage of water leads to ponding on the roof. Avp ensures that its roof vents and roof accessories install easily on membrane roofs and once installed can add years of life to a roof membrane.

Membrane roofing is often used on commercial flat roofs.