We recently had a new roof installed. We discovered that the interior opening is only about 1/3 of the size of the exterior ridge vent. Can you tell us what the interior opening measurement should be in proportion to the actual ridge vent?
Most ridge vents we've come across have about .5 to 1.0 inch opening on two sides, giving about 12 to 24 square inches of ventilation per lineal foot of ridge (less any loss due to foam baffles, etc.). So if your opening in the roof is about the same (say 2 inches wide), you will have about 24 square inches of ventilation. As long as the two are balanced, you should be ok.