When I install new shingles later this summer I would like to retro-fit ridge venting to my home. I have a "saltbox" style house and currently have soffit venting and gable venting. Several contractors have told me that if I add ridge venting I should seal the gable vents shut as the gable vents will "short circuit" the function of the ridge vent.
This result is not intuitive to me ... the gable vents being only at each end of the roof will help exhaust hot air perhaps somewhat diminishing the volume of exhaust flow volume from the ridge vent near the ends of the house, but overall I would think that "the more the better" (roughly speaking).
