When should you not use a ridge vent?

When should you not use a ridge vent? During heavy rains, deep snow or high winds along with rain can enter through the vent and stain the ceiling below. Most manufacturers state that a ridge vent should not be installed on a roof with a pitch (slope) of 3-1/2 in 12 or less.

During heavy rains, deep snow or high winds along with rain can enter through the vent and stain the ceiling below. Most manufacturers state that a ridge vent should not be installed on a roof with a pitch (slope) of 3-1/2 in 12 or less.