Ridge Vent Needed

Richard from Ohio asks the following: 

I just had my roof replaced here in the Cleveland, Ohio area. The roofers installed ridge vents. I have two gable vents and no soffitts anywhere. Was I misled as to the need to install the ridge venting.

Below is what our expert Joe Koch from Elite Construction Solutions had to say in response to your question:

A ridge vent is the recommended "exhaust" vent by manufacturers of roof vents. It's the only continuous exhast vent available. The roof needs to qualify for ridge vent which essentially means there is enough linear feet of ridge on the roof to allow for enough ridge vent to equate to the required NFA (Net Free Air).

Gable vents are intake vents.  Soffit vents are intake vents. The recommendation is to have balanced intake and exhaust vents as a part of the roofing system. 

The recommended intake with ridge vent is soffit vents because they can be installed fully vented and also be continuous.

Gable vents - intake and box (turtle) vents - exhaust create a tree effect that does not fully vent the roof.  However, sometimes homes don't have soffits or homeowners understandably do not want to invest in new soffit or eave vents and at the end of the day some venting is better than nothing. 

Follow Up Question: I had a roof that had three box vents and two gable vents. I had a new roof installed and the box vents were taken out and a ridgevent was cut in and installed. The company said its salesman made a mistake signing me up to do this. They want to comeup and take off the ridge vents and cover that area and reinstall box vents in the new roof. Am I being taken advantage of? We are seniors and on a fixed income. Help. Thanks