Puzzled over crack in wall

[speculator]

I have a 1970s built bungalow.

OK, what (I think) I understand.

I have cavity walls with brick outer and block inner
The load of the roof is taken on the inner block wall.

The problem is that on one section of wall, a crack has developed inside running diagonally from about 3ft above the floor and up to the ceiling. This is roughly below one of the major weight bearing points for the roof above.
However, there is no sign of any problem on the outer brickwork.
It looks as if there has been a crack filled before, a long time ago (10 years or more) and that this has begun to reopen. It is only around 1mm at present.

While I realise that the weight is on the inner wall, surely both walls share the same foundation and you would expect to see a problem in the outer wall if the foundation were subsiding.

Thanks for any thoughts

John

[welsh brickie]

sounds like a settlement problem, cracks do occur on all properties at one time or another if it was a major problem with the foundation the blocks would be split and the outer brickwork would continue to crack and move.
Dont worry, take pictures and check 6 months later, if it continues to widen then get a structural engineer to inspect it.Personally speaking I dont think its a problem.

[Perry525]

Due to constant movement over the year due to temperature change cracks do appear as blocks, mortar and plaster all have different rates of expansion.
The classic solution is to glue a strip of glass across the crack, if the wall is moving the glass will break.