In particular a warm roof system tends to be the ultimate protection from flat roof moisture concerns.
Roof vents for flat membrane roofs.
All flat roof vents including air intake vents and air exhaust vents are used together for balanced roof top ventilation.
The keepa vent is best used for flat roof attic spaces as an exhaust roof vent or fresh air supply intake roof vent.
Flat roof ventilation allows for the circulation of air in the property particularly for warmer rooms in residential buildings.
This slow drainage of water leads to ponding on the roof.
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.
We also cover spray applied foam and liquid roofing options.
There are two types of flat roof systems warm and cold roofs which affect the positioning of the ventilation.
No ventilation is required with flat roofs when the right membrane is used and installed correctly.
The keepa attic vent is built solely for flat roof ventilation a roof pitch that is 2 12 or less.
This is why the vertical height of the vents for flat roof ventilation needs to be at least 8 inches high.
A tough reinforced double layer membrane system should not be affected by interstitial moisture.
Attic vents relieve humidity during the winter and heat during the summer to help extend roof membrane life.
The short answer is.
However in many situations the insulation may need to be primarily or entirely below the flat roof membrane and between the roof joists if so what are the best options.
What is flat roof ventilation.
Collar height square flange and an inner louver wildlife guard.
When thermal insulation is placed below the deck the ventilation must also be on the underside.
Membrane roofing is often used on commercial flat roofs.
Roof vents need to be built tall for flat roofs because flat roofs drain water poorly and slowly compared to steep sloped roofs.
Flat roof ventilation is a niche that active ventilation products avp has supported and supplied for many years.
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.
Avp s flat roof vents are manufactured specifically for flat roof ventilation.
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.
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.
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.
