Cracks in lintel above front door

[ns33]

Hi.

I own a 1960s ex-council house. Lived here 15 years.
Cracks in plaster is common in my house, most of it hairline cracks.

However the cracks above the front door frame were causing the paint to peel, with some powdery deposits indicating water ingress. I decided to remove some of the plaster to see whats going on. Most of the render sounds like its blown, as it makes a hollow sound when knocked.

Whats bothering me is a crack running along the lintel, when looked at from beneath.

Time for a structural engineer?

 

[tony1851]

Yes the lintel has failed, caused by expansion rusting of the steel reinforcement. Water has obviously been getting in somewhere. In the 1960s, they generally didn't bother too much about cavity trays above lintels.
Ultimately it would need to be replaced by a couple of steel beams running parallel (one under each skin). But I don't envy anyone who has to get that beast out first!

 

[ns33]

Thanks Tony. Is this the kind of thing I can keep an eye on for movement or will it need replacing ASAP? Not expecting a "concrete answer"...

I checked outside and there is no other signs of movement. There are a few small gaps where the outside portion of the lintel meets the outside wall. I could fill those to see if it stops the water ingress.

 

[stuart45]

Is it a boot lintel?