Hairline horizontal/diagonal crack in corner of upstairs wall

[CruiserProT1S]

Hi guys,

Just looking for some opinions/advice on a recurring hairline crack - its situated in the top corner room of a 1940-60s semi-detached. Situated close-ish to a busy road, and only reoccurs in summer-time. That said, its quite long, and its horizontal/diagonal.

Photo isnt the clearest - but it follows that red line (just above it) and terminates approx where the red line on the left is. Previous owners have clearly (badly) patched it with fillers which is evident in the wall texture around it.

What do people think this is - should I be concerned from sturctural perspective?

Thanks in advance!

 

[Wayners]

Stress crack because of the lintel above window.

Knock plaster off.
Fill crack in brickwork around lintel to right hand side of window.
Cover area with a metal lath.
Plaster over.

That is one way to fix.

Other way is to use drywall tape in the surface of the plaster and smooth over. Problem is the movement maybe too much