ventilation requirements for attic of commercial bldg

[ssylvest]

Will it likely pose a problem to remove the ventilators on the top of a commercial building. We have a 40 year old commercial building that will soon get a new roof (changing from a built-up roof system to a simgle ply membrane roofing system). The roofing contractor suggested removing the existing turbine "whirlybird" ventilators to save on flashing cost and leak potentials. He felt like they were not needed and he noted they are not on most similar buildings in shopping centers.

The building has a suspended ceiling (on track grid) with 2' x 4' ceiling tile panels that have about 1.5" insulation. Above those, all the HVAC ducts, sprinklers, and pipes are run. Then the roof is metal deck with lightweiht concrete with the built-up roofing on top of that.

Thanks for any advise or recommendations to other references.

 

[Ron]

If the ceiling is not directly applied to the roof framing members, there is no requirement to ventilate the attic. In most commercial buildings with flat roofs, there is no ventilation provided for the "attic" space.