We are in a 1930s bungalow and thinking of getting a loft conversion done. Roof is pitched and slated on all four sides but also has a concrete corbel running around the perimeter. The visible part of the corbel sticks out the wall about 150mm and has a similar depth. It may even be forming the cavity closer. Slates are straight onto the sarking boards i.e. no roof felt. The roof currently has roof vents and there are no condensation issues in the loft (freezing in winter but boiling in summer). If we go with a new breathable membrane under new slates and put insulation between the rafters with an air gap, will it matter that there is no air flow path via the eaves? If we need an air path at the eaves how is this normally achieved in this type of build.