brickwork on my roofline in loft is moving

[richard82]

i have noticed the top line of bricks in my loft has progressively moved towards the outside wall of my home, i have lived here for 5 years and now it is at the point of being very noticeable, my home is a 3 bed semi-detached, this wall that is moving is the detached side, i have noticed bits of morter/cement that have dropped out also small bricks.
i have checked the rest of the brickwork in loft and appears no other movement, the opposite wall (attached side) has been bricked just below the roof trusts (wooden frame on roof) so any movement of roof would not affect these. i can not see any movement from outside of home on the apex due to facia and soffit, i believe the home to be built 1850s, there is slight cracking to some corners of bedroom walls which are progressively growing the cracks are internal but on external walls. my home is situated near the top of a hill.
i had a wall removed in my bathroom approx 1 year ago but this was a free standing breeze block wall, no other major improvements.
i have no slates fall off roof but have noticed chimeny stack (external) does need re pointing, could be an indacation of movement .

i have included photos to hopefully help asses whats happening and would appreciate any advise

[welsh brickie]

Very hard to comment on exactly what it could be,My best guess is expansion of roof timbers,or tiles expanding to crack the brickwork.It dosent appear to be structural.I would render over the brickwork thats moved and any other cracks you may have.
If there is any additional movement contact a structural engineer to examine it.

[polishingpeanuts]

Richard, its difficult for us to determine from the photos, but their seems to be some mortar on the purlin a little way in from the gable.

Is the purlin coming out of the wall? or rather is the wall moving away from the purlin?

Been in many hundreds of roof spaces and not seen anything quite like that. :(