Help - Long diagonal ceiling crack suddenly appeared

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Hello, looking for some help on this long, diagonal crack that has appeared on the living room ceiling of my victorian house (waiting for the professional to visit but looking for someone to help in the meantime).

This diagonal crack appeared last night out of nowhere so quite concerned. I had been drying clothes on an airer for a few hours in that room yesterday along with a dehumidifier to help with the humidity. Could that be the cause or could this be a bit more serious? Im worried that it was so sudden. We have had a lot of rain over the last few days but no visible leaks.
IMG_8942.jpeg


The new line is the one i have underlined in red. The other one has been there since we moved in and likely a rubbish job at plastering over as you can also see where they painted over it.

Bought the house earlier this year so this will be the first autumn/winter.



Thanks for your help.
 
At the point of crack cross give it a gentle push. Any movement? That looks to me like it's coming away and could fall in.
Might need to prop up with T bar you can make and get it looked at asap
 
At the point of crack cross give it a gentle push. Any movement? That looks to me like it's coming away and could fall in.
Might need to prop up with T bar you can make and get it looked at asap
Thanks for your reply. No movement when we push it, but it has dipped down slightly where the two cracks meet. Based on what you see do you think it’s structural or bad plastering?
 
That looks to me like the ceiling is failing. As Wayners said, get it looked at Asap.

If its an original ceiling, then i'd say its failing. If its plasterboard, it may be that it was nailed or screwed insufficiently and can be reattached and reskimed.

Is your lounge a ground floor room? Is the floor in the room above still flat or has that dipped too?
 
That looks to me like the ceiling is failing. As Wayners said, get it looked at Asap.

If its an original ceiling, then i'd say its failing. If its plasterboard, it may be that it was nailed or screwed insufficiently and can be reattached and reskimed.

Is your lounge a ground floor room? Is the floor in the room above still flat or has that dipped too?
Thanks for your reply. No dipping in the bedroom floor above, but it’s laminate over floorboards so not sure that it would show. Just really odd that is was so sudden. Moved in a few months ago so not really sure if it’s original ceiling or just plasterboard.
 
The ceiling is clearly moving, hence the decoration marks. Its probably been filled and painted over, but the cause of the movement hasn't been addressed so it's just cracked again.

Any heavy furniture or weights in the room above?
 
The ceiling is clearly moving, hence the decoration marks. Its probably been filled and painted over, but the cause of the movement hasn't been addressed so it's just cracked again.

Any heavy furniture or weights in the room above?
Thanks. That’s helpful. Nothing majorly heavy that wasnt there before. Part of the wardrobe sits above the crack but it was the wardrobe was there when we moved in too. We havent dropped anything heavy recently either.
 
Thanks. That’s helpful. Nothing majorly heavy that wasnt there before. Part of the wardrobe sits above the crack but it was the wardrobe was there when we moved in too. We havent dropped anything heavy recently either.
If there's nothing heavy in the room above, it'll be the plaster or plasterboard detaching itself from the joists of the floor above.

If its lath and plaster, it may have just reached the end of its life and the plaster nibs have failed. It'll either need to come down and be replaced with plasterboard and skimmed, or some people plasterboard over the existing ceiling and effectively use the new plasterboard to hold up the old ceiling.

It sounds like a massive job, but its not. Just very messy if the old ceiling has to come down.
 
It looks like it might be a lath and plaster ceiling.

How old is the property?

I have had a few customers with 150 year old houses, in the middle of the night ceilings have suddenly collapsed.

I am not saying that is going to fall down but it does happen.

As per @Lower 's post. The customers screwed plasterboard up to prevent the mess of removing the old ceiling. Not relevant to you, but it also helps to preserve the in-situ run cornices.
 
I've known plasterboard fall like that.
You can't see the nail head popping as behind the plaster skim.

Causes can be rubbish on the plasterboard with the weight or not long enough nails that pull through over time.
I looked at one once on a job I let myself in on. That fell on one end and other end was under a light fitting, so I held it up for nearly 3 hours until someone turned up.
I was just going to let it go but there was expensive furniture under
That one was double boarded and skimmed for fire proof but the nails were too short.
What a day that was!
 
It looks like it might be a lath and plaster ceiling.

How old is the property?

I have had a few customers with 150 year old houses, in the middle of the night ceilings have suddenly collapsed.

I am not saying that is going to fall down but it does happen.

As per @Lower 's post. The customers screwed plasterboard up to prevent the mess of removing the old ceiling. Not relevant to you, but it also helps to preserve the in-situ run cornices.
Thanks for your reply. The house is about 120 years old. Assuming the problem is just that the ceiling is failing how long would this take to fix? Is a partial ceiling repair relatively simple and quick?
 
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I've known plasterboard fall like that.
You can't see the nail head popping as behind the plaster skim.

Causes can be rubbish on the plasterboard with the weight or not long enough nails that pull through over time.
I looked at one once on a job I let myself in on. That fell on one end and other end was under a light fitting, so I held it up for nearly 3 hours until someone turned up.
I was just going to let it go but there was expensive furniture under
That one was double boarded and skimmed for fire proof but the nails were too short.
What a day that was!
Thanks that’s helpful. We do have furniture underneath the ceiling so wouldn’t be ideal if it falls. Is it a relatively simple job if it’s just plasterboard that is coming off for no other reason than it is old?
 
Thanks for your reply. The house is about 120 years old. Assuming the problem is just that the ceiling is failing how long would this take to fix? Is a partial ceiling repair relatively simple and quick?

Sorry, I cannot answer that question.

Lath and plaster- they are thin strips of timber (AKA laths) nailed to the joists. The plaster would have been pushed in to the gaps to hold it in place. The plaster splurges over over the top of the laths and holds it in place. In time it fails. The splurged bits eventually fails though. They often used animal hairs to give the plaster more "body".

You might be able to get someone to cut through the laths and patch in plasterboard. I have seen it done, and it worked.

I would guess that it, the ceiling, might be reaching end of life though. But, I am a decorator rather a plasterer.

I have no idea how old you are but perhaps consider getting someone to overboard with plasterboard (long screws in to the joists). If you plan to be there for another 20+ years.

When they fall down, it is really messy. You have all the rubbish above to deal with as well.
 
Thanks for your reply. The house is about 120 years old. Assuming the problem is just that the ceiling is failing how long would this take to fix? Is a partial ceiling repair relatively simple and quick?
Depending on the size of the room, 1 day to bring the ceiling down and clean up, another to board and first coat skim, 3rd day to 2nd coat skim.

1 day less if you overboard rather than bringing the ceiling down.

Then redecorate.

I caveat the above with the fact that I’m an enthusiastic diyer, have never plastered myself, but have over boarded a few ceilings and then had then skimmed as described above.
 

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