Wall plate movement

[James35Bath]

Hi all. I've recently moved into a 1930's semi detached home which is in need of restoration. I am just after some advice in a particular problem I have.
I noticed a fairly large crack, of about 5mm which has been filled several times in the past, it runs through the back bedroom and into the landing area. Also the very top part of the wall in the back bedroom kinks outwards, probably the top 6 inches or so.

I've removed some plaster and render from the wall to find out what the problem is. What I think has happened is the wall plate has shifted outwards by about 15mm and has taken the plasterboard with it, hence the large crack. The roof also looks like it's slightly bowed.
I'm unsure how long the crack has been there but the plasterwork seems like it's from when the house was built.

The house has had new felt and tiles which I think may have been done back in 2000 or so.

Should I leave it and re plaster and keep an eye on it or does something need to be done?

This is my first post on here but will try and attach pictures.

 

[James35Bath]

Untitled

• James35Bath
• 15 Sep 2014
• 1

Untitled

• James35Bath
• 15 Sep 2014
• 1

 

[ree]

Pics in context needed, and pics of the exterior elevation and roof line.

The ceiling joists in the room shown will be nailed into the rafters - can you go up into the small loft, and see if the nailing is distorted?

From outside can you see any cracks or bulging?

Do all door & window heads look level. Do all doors and window sashes open easy?

Do the neighbour's have slate or tile on their roofs?

 

[James35Bath]

Thanks for the reply ree. Sorry, bit of a rushed thread on phone at work. Outside is rendered but no cracks. Where I've pulled away the plaster I can see that the brickwork hasn't moved, the wall plate has moved outwards by about 15-20mm.
The side of the room in question is sloped and the plaster board attached straight to the rafters. I shall go into the loft and check the joints, however I'm slightly concerned about the loft insulation containing asbestos.
I've spoken to a surveyor today who surveyed the front wall of the house before I bought it, he noticed the crack and said it's nothing to worry about, he said just to brace the joists and rafters.
Think I will just do that and re plaster and keep an eye on it.
I have noticed the roof is slightly bowing in so may put some uprights in between joists and rafters to give some extra support.