It makes me laugh these so called breathable membranes. Some on the market have a bit to be desired . So you end up venting the roof anyway. The eve support trays are a brilliant but simple idea. I have noticed some of these are getting thinner and smaller.
Good afternoon, Rafter Roll has to sit higher than where the insulation finishes so there is no contact between the insulation and roofing felt. The width of rafter roll required will depend on the pitch of your roof.
This doesn’t really help to understand the product. For example can it be applied onto cleaned zinc which has failed with small holes? Data sheet says lay it on thin, two coats, but experienced users say lay it on thick in one, etc. Unfortunately the data sheet doesn’t give this info as well