How Much Ventilation Does A Flat Roof Need

Federal housing authority recommends a minimum of at least 1 square foot of attic ventilation evenly split between intake and exhaust for every 300 square feet of attic floor space.

How much ventilation does a flat roof need.

Enter square footage calculate or enter the square footage of the attic or area to be vented. Take for example ridge vents. You only need ventilation in a cold roof. While hardly anybody agrees on the best roof ventilation system everybody agrees some roof vents do hardly any good at all.

No insulation is on top. Any type of roof from tpo to epdm can be either hot or cold. How much ventilation does a flat roof need. Ventilation is not needed in a warm roof.

Flat roof vents have no moving parts to break or squeak but don t vent as much air as wind driven vents. A cold roof or hot roof. Choosing the correct ventilation solution for a flat roof will play an integral role in extending a structure s lifespan. The majority of roofing experts agree that ridge vents are the most effective and cost effective roof vents available.

The answer depends on the type of roof you have. It makes sense as all of us know that the most humid rooms in the house like the bathroom and kitchen need it. However we rarely think like that for roofs even though they undoubtedly require ventilation. Proper attic ventilation consists of a balance between air intake at your eaves soffits or fascias and air exhaust at or near your roof ridge.

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. A cold roof is where all of the insulation is placed either between and under or completely under the joists or deck. Hot roofs have the roof deck then insulation then the roofing material. In this way the roof itself is kept cold.

I have roof vents so i have roof ventilation. How much ventilation does a flat roof need. It s unavoidable that the thermal temperature in the roof space will bear the brunt of the heat generated in the living spaces below. 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.