Lathe & plaster ceiling falling down

SameOldRoundabout

I need some advice please. The ceiling in my sons room has had a small crack since we moved in 18 months ago, but over the last few months has got worse and is now noticeably dropping, with the crack now extending up through a good 4 feet of the coving. We can’t currently afford someone in to take the lot down, how can we make it safer? Cut a section out? Put a prop between the wardrobe and ceiling? The rest of the room looks ok but this section is pretty big and the plaster will be thick and heavy so I’m worried. The worsening seems to be quite slow but obviously once it passes a certain point it will just collapse. Can this be repaired or does the lot need to come down and be replaced with plasterboard? My husband is great at plastering but we’ve never dealt with lathe and plaster before. 

SameOldRoundabout

Picture did not attach! 

Section62

SameOldRoundabout said:

We can’t currently afford someone in to take the lot down, how can we make it safer? Cut a section out? Put a prop between the wardrobe and ceiling? The rest of the room looks ok but this section is pretty big and the plaster will be thick and heavy so I’m worried. The worsening seems to be quite slow but obviously once it passes a certain point it will just collapse. Can this be repaired or does the lot need to come down and be replaced with plasterboard? My husband is great at plastering but we’ve never dealt with lathe and plaster before. 

Usually I'd lean towards taking the whole lot down and starting fresh, once laths start to fail it is a good sign that more are going to follow.

But you've got some interesting cornice there, and if that's an original feature you want/need to keep then it might tip the balance towards making repairs instead - especially if your budget is currently limited.

What is above that ceiling?  Is there a loft, and have you got access to it?  Before deciding what to do you really need to be able to inspect from above and get a better idea of what is happening.

SameOldRoundabout

Our third floor is above that, which is our bedroom/dressing room and en-suite. Right above this is a stud wall (above the same wall as in this room) and directly above the crack is a dressing table so not much footfall. However the house has previously suffered movement on the opposite side to this crack and we have replaced the entire third floor with sheet boards which are screwed down, carpeted over and then have new stud partitions and built in furniture on top. Annoyingly. So we can’t access from above. The house is 125 years old so I assume the nibs are just slowly failing, exacerbated by renovations above last year. I’d like to keep the coving, but I also quite like my son so if it has to go for safety sake I’ll be okay with it. 

After Christmas we can get someone in to either repair or remove it entirely and replace but funds are limited until then sadly. 

GDB2222

It’s hard to tell from the photo. How much of the ceiling is loose?

You can give it a prod with a broom to gauge the movement. If it stays up despite a good prod, is it really going to fall down soon? Obviously, whilst you can stand underneath whilst doing this ….

If it’s a large area, you can screw some battens to the joists. If it’s a small area just cut it out or prop it up for peace of mind.

GDB2222

Great cornice by the way. I hope you keep it. The plasterer will just want to plasterboard over what’s there, but that won’t work well with the cornice. Maybe it’s for the best, though. 

justwhat

Always try too repair lathe plaster cracks straight away...small hairline cracks are very easy.

you now have a bigger problem. the crack has now spread  and is effecting the cornicing. 

cut the old plaster out before it falls and creates more damage. keep cornicing intact and repair . fix rest of plaster when you have the money.

grumbler

Try to push it up manually. If it moves easily, i.e. it's only the plaster falling apart, not some broken joist, then locate the joist(s) and screw the plaster to them in multiple points- gently, not allowing the screws heads to go through the plaster.

justwhat

grumbler said:

Try to push it up manually. If it moves easily, i.e. it's only the plaster falling apart, not some broken joist, then locate the joist(s) and screw the plaster to them in multiple points- gently, not allowing the screws heads to go through the plaster.

you cant screw plaster to joists you may be able to screw the lath to joists. But usually you just cause the plaster to crack even more.

ChasingtheWelshdream

I am not in any way an expert, so please defer to others, but we have similar coving and I have recently repaired similar damage as we wanted to keep it. 

I went over the whole ceiling and prodded to gauge if there was any actual movement or signs of looseness other than the cracks. Where the surrounding plaster seemed sound, I scraped and widened the cracks, priming with pva ready for filling.

I filled these first with lightweight filler (One Strike I think it’s called), then fine surface filler to finish.

In other areas, it was obvious a wider area had failed. I scored around the section and pulled the plaster off - only if it fell away easily - stopping once it reached an area that was more resistant.

In a couple of places I cut and replaced some lathes with strip wood as it looked like the gaps were rather large. Primed with PVA again as the lathes were rather dusty.

I then simply patch plastered and used tape at the edges. I think it was 3 coats in all. The hardest was the first layer as I wanted to endure the plaster went through the lathes enough to squash round the back.

Now I have never plastered before, so it may well not be perfect, but I managed to get the areas to blend in rather well and will . I found a good YouTube video of someone in America repairing lath plaster work that helped. He suggested going over lightly with a paint roller as a final finish to take off the smoothness of the new plaster, so it blended better with the old. I tried it and wasn’t convinced but worth bearing in mind. 

For the coving, again I had to remove a fair bit, but then built it up again with many, many layers of filler. I made a kind of former from the existing and sort of ran it along the gaps so it moulded the filler to the right profile. Again, not perfect but good enough for me. Took a long time though!

Overall I’m really pleased with how it turned out so was definitely worth the effort to save the features. I accept that at some point it may need further repairs, and eventual replacement, but will do for the foreseeable.

As I say, I’m just a diy-er, but something similar may be an option for you?

SameOldRoundabout

On closer inspection we can see there is now a large 5mm ish wide crack in the rear of the coving on the chimney breast. This wasn’t there a week or so ago. We’ve drilled an inspection hole and the whole plaster sheet is a good inch or two off the laths above, we can easily push the plaster back upwards which I don’t think is a good sign, although it hasn’t fallen down yet. The top of the wardrobe has lots of tiny white flakes and plaster dust on it where it’s been worsening. For now we’re going to prop the “good” section, cut out the falling section and then use wooden batons under the sound section of ceiling into a joist. I’m gutted as I hadn’t realised the crack was spreading across the chimney breast as well as the opposite wall! We’ll lose the coving and the entire ceiling in the end I think but hopefully taking down the worst and supporting the rest will give us a few weeks to get ready to remove the rest and replace.