Metal Roof Venting Requirements

Additionally if the span is greater than 10m the overall ventilation area should be increased to at least 0 6 of the total roof area.

Metal roof venting requirements.

It uses the natural effects of rising hot air from outside of the home to remove the heat that builds up in attics in warm weather and the heat and moisture that collect during cold weather. Structures that house people animals and or valuable material also benefit from cross ventilation using ridge vents near the roof and a louver vent located closer to the structure s floor. Based on your 1100 sq. Duo pitch roofs greater than 200 pitch or greater than 10m span should have additional ventilation at the ridge to assist airflow through the roof void equivalent to at least a 3 mm wide continuous gap.

The building codes are beginning to address these methods of construction. A metal roof typically does not increase nor decrease the need for ventilation. My options have narrowed to. Static ventilation is a simple concept.

If your roof is 1200 sq ft soffit floor space you will need 4 sq feet of roof ventilation. May require more than one type of ventilator to allow air to move between them cross ventilation. And this guideline you ll need a minimum of. Metal sub girts which raise the metal roof either 1 2 or 1 from the substrate or 1x3 wood purlins which raise the metal roof 3 4 from the substrate.

Most metal roofs like other roofing materials rely on static ventilation using natural airflow rather than electric fans to create air movement. There should also be a 50 50 balance of attic venting and roof venting. In a cold climate the primary purpose of ventilation is to maintain a cold roof temperature to avoid ice dams created by melting snow and to vent any moisture that moves from the conditioned living space to the attic. Ventilation that meets code requirements is adequate for any type of roofing material including metal.

Near ridge of the roof. But the internal load dictates that i have to do that he says. Generally structures larger than 2 400 sq. According to their requirements you should have 1 square foot of attic ventilation per 300 sq ft of attic floor space.