Flat Roof No Attic

Flat roof ventilation is achieved by creating air changes to the attic or plenum.

Flat roof no attic.

An attic you want vented but in your case you want the ceiling roof space sealed. Ventilation is crucial to these areas as they affect the building as a whole both inside and out. And i m wondering if this product can be used to keep the rooms below the roof cool in the summer and warm in the winter. If you put cellulose up there it will help insulate but you need a vapor barrier above the ceiling because you ll have warm ceiling air hiiting colder roof surface and condensing which will turn the cellulose into a moldy mess.

Because most flat roofs don t have an attic crawl space or venting the insulation must go underneath the roof s covering on the exterior of the home or be placed on the inside of the home. Roof vents on flat roofs need to be sufficiently sealed and positioned off the roof so water cannot seep in through them. Removal of excess heat and moisture will help the life of the roof and will help the functionality and efficiency of the hvac systems. Well in terms of the summer that s an easy one.

Across the us the majority of flat roofs either have no ventilation at all or are poorly vented. As a result if you open up most flat roofs especially those located in places like arizona you will see a lot of moisture rot and mold as a result. 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. Original design had a tar and white gravel roof with soffit vents in the eaves.

I have a mid century modern home in southern california with a 4 12 pitch and no attic space. 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. This is due to faulty original architectural design that did not take proper venting into account. Ok so you have a flat roof with no attic and you re looking for a roofing product that s going to give you some thermal qualities.

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. Flat roofs do not have eaves so there are no soffits holes on the underside to allow air flow.