Cracks/gap in brickwork beneath window

[mosmosmos]

Hi,

Boredom caused by lockdown resulted in me investgating some of the 'small' cracks in one of my rooms...

This is a 1st floor window of a 1930's semi, above the main door. Upon going back through the documentation for the house purchase (a year or so ago) , I can see the sellers included a regularisation certificate for the windows from when they bought it (2007), so god knows who did these and to what standard. Potentially first double glazing so heavier windows than were originally in there.

There doesn't appear to be anything up with the wall on the ground floor, though the door does stick slightly and doesn't seem to hang at an exact right angle.

It initially looked like the line in the picture before I pulled off a bit of the paper to reveal the plaster. Though pushing a thin long stick through the crack went all the way to the exterior wall so I had to take off some more.

I pulled off a bit of the plaster around the crack to actually see what was going on behind, so this might look worse than it is;

And this is a bit of a closer up view of the underlying brick work from the upper part of the crack. Appears than the gap is where the mortar is (was), there is still some black stuff (lime?) further down where the gap isn't so large.

There was only a hairline crack in the plaster for the vast majority of the crack, which would suggest that the gap was simply plastered over, and/or it hasn't moved since? Though as you can see, it was slightly wider at the top. One of the triggers for me looking at this in particular was I thought the window got a bit more difficult to close.

You can see the another crack running up through the cement/mortar on the outside on the left, which broadly lines up with the one inside, you can see a little daylight through from the inside.

Now I've absolutey no building or structural knowledge at all, so really trying to get an understanding of the potential cause, steps to take and likely path and cost of remedial action, and whether I'll need to start stripping the plaster in other rooms to see if it goes throughout.

Any advice/guidance would be much appreciated.

Edit: Think I've worked out how to put better pictures on

 

[oldbutnotdead]

Where are those cracks in relation to the front door (which is also presumably plastic)?

 

[mosmosmos]

Where are those cracks in relation to the front door (which is also presumably plastic)?

Hi,

Yes, directly above. Again plastic, expect it was installed at the same time.

 

[oldbutnotdead]

Predictable. Good odds no lintels were installed above the new doors and windows, the original timber frames could take quite substantial loads from the brickwork, plastic windows will take precisely zero load before deforming. Don't put too much faith in the regularisation by the way- generally all Building Control look at is the thermal performance of the windows (and whether the right type of glass is in windows near the floor)
So your investigation needs to determine whether anything is supporting the brickwork above the front door to start with, especially if it is starting to pick up. Problem at the moment will be getting repair materials or personnel if lintels do need installing so try and be as non-destructive as possible (you may be looking at the holes for a few weeks). And don't fret too much- if that's all the movement in 13 years the place is not going to collapse tomorrow

 

[mosmosmos]

Predictable. Good odds no lintels were installed above the new doors and windows, the original timber frames could take quite substantial loads from the brickwork, plastic windows will take precisely zero load before deforming. Don't put too much faith in the regularisation by the way- generally all Building Control look at is the thermal performance of the windows (and whether the right type of glass is in windows near the floor)
So your investigation needs to determine whether anything is supporting the brickwork above the front door to start with, especially if it is starting to pick up. Problem at the moment will be getting repair materials or personnel if lintels do need installing so try and be as non-destructive as possible (you may be looking at the holes for a few weeks). And don't fret too much- if that's all the movement in 13 years the place is not going to collapse tomorrow

Thanks for that, would make a lot of sense. Looks like there is some sort of metal thing directly above the door, though I'm going to assume that this is likely to be some sort of very light duty thing on its own, without the ability to hold it up effectivey.

 

[oldbutnotdead]

Thats a positive sign, looks like the underside of a lintel & in good condition too so the outer skin is being supported. Though i'd be more impressed if the lintel was being supported by the brickwork either side...do all the houses on yr street have that wide door/window setup?

Question is, is the inner half of the wall held up by anything? (from looking at your brickwork I'm fairly sure you have cavity walls- no soldier courses in the pics)

 

[mosmosmos]

Thats a positive sign, looks like the underside of a lintel & in good condition too so the outer skin is being supported. Though i'd be more impressed if the lintel was being supported by the brickwork either side...do all the houses on yr street have that wide door/window setup?

Question is, is the inner half of the wall held up by anything? (from looking at your brickwork I'm fairly sure you have cavity walls- no soldier courses in the pics)

All the houses on the street are different, but the other side of this semi has a wide door which is relatively new, however unlike ours still has a timber frame.

Though now I'm starting to understand what to look for, it's making a lot more sense. I've found a google maps drive past from 2008, and it's clear that all of the brickwork above the door has since been repointed, which I imagine would be consistent with a lintel being inserted. I'll have to get someone to look into whether the inner wall is supported.

Thanks for you help, much appreciated.

 

[oldbutnotdead]

Nice big magnet would be your first test, after that you're into poking holes in the plaster and having a look