Advice needed on replacing a slate roof with asphalt shingles
Our son has a small 1941 slate roof house which needs reroofing and given the type of house it is it is definitely not worth going to the expense of using slate again. So asphalt it will be.
The enclosed attic space is well insulated from the living area below (trap door access)but given the low roof profile - it is very hard to stand even in the middle - this area gets very hot in the DC area summers. The brick house has one gable vent which seemed to have been standard for these kind of houses in our area.
In thinking about this project a couple of questions come to mind:
Is it possible or advisable (or even necessary for the asphalt shingle warranty as I have read) to install some kind of additional venting system?
Can the wood planks under the slate be used again instead of plywood which I have read can delaminate?
Any advice very much appreciated as others must have faced this before.