changing from slate to asphalt and can I ventilate?
Our 1941 slate is pretty well worn out (although no leaks as yet) and as we do not want to go to the expense of slate again on this low slope roof we will install an asphalt shingle roof. We are hoping to be able to use the boards already there as decking as in another similar house we saw they were close together. But the question is whether we can have any additional ventilation at this time. We have one gable vent only so you can imagine this small enclosed attic space which is only used to store boxes gets very hot and with a slate roof there is more air circulation I know than there will be with a shingle one. There is no overlap of the roof so we cannot install soffit vents to provide intake air for a ridge vent so any suggestions appreciated.
You will probably have to install sheathing(plywood or OSB) over the current sheathing if 1x6 or similar. Or install self stick ice dam material over the whole roof. Installing a ridge vent can't hurt, but it will not be as efficient as with soffit vents. An additional gable vent would help.