Cracks on the outer wall, should I be worried?

[EmilyT]

Can I pls ask for some advice on these cracks of my outer wall under the window as shown in the photos? Could I fill it up myself? The widest part if more than 2mm near the window but the rest were pretty narrow with less than 2mm.  The house was build in the early 80s without modifications since.  Thanks a lot in advance.

[Mr Punter]

These cracks are fairly common.  On a new build this can be reduced by adding a couple of rows of stainless bed joint reinforcing above and below the openings and using a mesh with the render.  For you it is just rake out the cracks, fill with sand / cement and repaint.

[EmilyT]

Thank you, should I be worried about the lintel or the sill being failed?  

[Mr Punter]

Nothing to worry about.  Just rake out, repair and paint to stop water getting behind the render.  You could give it a tap with a hammer to see if it sounds hollow.

[saveasteading]

22 minutes ago, EmilyT said:

should I be worried about the lintel or the sill being failed?  

No. It is normal for cracks to run from large openings in walls. The lintel will be unaffected.

How long has the crack been visible? Has it changed recently?

 

If if it is to 2mm on the surface  it is probably  less on the masonry.  Raking out some render will show. 

[EmilyT]

Thank you, the crack has been there for more than 10 years.  The inside wall where the outer crack was looks fine, but the inside wall above ( also has a window) cracked a bit under the window, not sure if this is serious...