Flat Roof Ventilation Detail

Unlike vented facades or pitched roofs flat roofs do not have sufficient height differential which is a driving fac tor for air movement within a cavity.

Flat roof ventilation detail. Hot roofs have the roof deck then insulation then the roofing material. The answer depends on the type of roof you have. When thermal insulation is placed below the deck the ventilation must also be on the underside. Flat roof ventilation is achieved by creating air changes to the attic or plenum.

Ventilation is vital to make this type of flat roof construction work. Any type of roof from tpo to epdm can be either hot or cold. A vapour control layer is still installed to minimise any moisture movement. Removal of excess heat and moisture will help the life of the roof and will help the functionality and efficiency of the hvac systems.

Banding is typically used to seal soil vent pipes on single ply roofs such as fdt rhepanol pib and involves wrapping an unreinforced membrane around the pipe to a minimum height of 150mm. Find all available details and drawings of vents for flat roofs in the format dxf pdf and dwg as downloads here. A cold roof or hot roof. 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.

There are two types of flat roof systems warm and cold roofs which affect the positioning of the ventilation. Alwitra flat roof details. It depends on where the insulation is installed. 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.

Since february 1997 active ventilation products avp has been a supplier of roof vents roof jacks and whole house fans for fema federal emergency management agency housing hud united states department of housing and urban development housing and for those in the modular commercial and residential markets. How much ventilation does a flat roof need. Flat roof ventilation is beneficial to flat roofs in all climate zones no matter the color of the roof. Flat roof ventilation allows for the circulation of air in the property particularly for warmer rooms in residential buildings.

If there is not sufficient air exchange the construction is likely to fail. This system is probably the most common arrangement for residential flat roofs.