Our small, mid slope, 1940s slate roof is nearing the end of its life (slate pretty soft) and redoing it in slate is out of the question. The low attic area enclosed and accessed by a trapdoor is very hot but there is no moisture build up that we can see. There is one gable vent at the moment in one side of the brick house. How if at all would we vent a new asphalt shingle roof - we wold use the boards if they are tight enough to go under the shingles but with shingles the space would get hotter I would imagine. There is no possibility of installing soffits so it would appear that a ridge vent would be useless or counterproductive in that it might draw moist air from below. Would we be better not adding any more additional ventilation?. Thanks for any help.
Actually if you want the slate look GAF has come out a synthetic type of slate shingle. Its much cheaper than regular slate but still not cheap. You may want to look into that.
Hicks makes a vented drip edge, and there’s a couple of shingle over products available that others out here have used, but IO am not familiar with. I designed my own vented fascia that works pretty well, but doesn’t allow an easy option for gutters if I decided to put them on later
You want your vents to draw out moist air.
Smart Vent will provide your intake air.
Thanks for the replies. We definitely need gutters but a bit more information on the system that provides intake air posted by the last posted would be helpful. Thanks.