roof help....undercloak

[b21playa]

need to replace the mono pitched roof over my garage and porch. Currently its been done with felt tiles, but i want to change to clay tiles to match house

as there is no brick wall on oe side, how would i fit the undercloak?

 

[cumbrianroofer]

if you dont have a brick gable end then is it a timber barge board if so much easier to fit undercloack just nailed in to place have you got any pics