Blocked eaves? Loft Condensation? (ed.)

This question has been asked and answered in many different forms on this forum but i think the specifics of this example are a little different.

1930's house
slate roof
non-breathable felt membrane
sarking boards

No roof vents, no ridge vent and no vents at soffit/eaves.

Really really bad condensation in the roof space despite good insulation and NO-ONE currently living in the house and no central heating at the moment.

The condensation has got worse as the temperature has got lower recently. To be expected i suppose.

However, the eaves detail on the house is a bit odd. There seems to be a cement/mortor fillet between the rafters at the wall head (top of wall).

See attached. Ignore all the numbers (it's a generic detail from google) but focus on the yellow blob. Imagine this was tight to the sarking and between the rafters at the wall head (top of wall) and that is was we have inbetween each and every rafter/eave space.

I'm assuming this fillet means no air flow and therefore condensation?

Can i just remove this fillet of concrete (and replace with some mesh to stop birds/animals etc)? Or drill holes in each one?

It doesnt really do anything other than block the space off.

Any help would be much appreciated.

Thanks.

wilco88, good evening.

Suggest you simply try knocking out this cement fillet? nothing to loose really??

Does your eaves detail overhang the external walls?

Ken.

No, eaves don't overhang. Will have to try getting rid of the cement fillet as a first attempt.