ing can result from high wind conditions near big trees or adjoining roof lines. in these cases, increasing the vent height may solve the problem. Roof Pitch Minimum Vent Heigh Feet Meters flat to 7112 2 0.61 over 7/12 to 8/12 2 0.61 over 8112 to 9/12 2 0.61 over 9/12 to 10/12 2.5 0.76 over