We’re in the process of insulating and renovating an unfinished attic space in a 1915 home. Our assumption going into the project was that we would allow space for ventilation behind the insulation (under the roof) so that air could pass from the soffit vents to the ridge vent.
Well, it turns out that we actually don’t have soffit vents, and we don’t have a ridge vent, either. Looking up an down our street, it appears that all the homes on our street don’t have soffit vents.
So, the GC has suggested using closed cell or open cell foam to fully insulate the roof, and forget about ventilation altogether.
Because we have a slate roof, putting in a ridge vent would be very costly. I’m not really sure if it would even be useful, because it wouldn’t have anything to ventilate.
This is a pretty dramatic step, so I’m looking to collect as many opinions as possible before dramatically altering our roof in this way. We live in the NE, so avoiding ice dams is an issue.