Victorian Cornice Repair - What Product

[rossyl]

Hi

The previous owners were awful at property maintenance and it appears that an overflowing gutter left for years has caused this section of Cornice to get damp.

It now has a crack running a couple of metres.

The gap isn't too large.

I'd like to try and save it.

We are having work done later this year, if it falls down during the course of that building work, so be it, but, I'd like to retain as much as possible.

Recommendations please...

Looking for the best product that will bind the dropped part of the plaster cornice to the remaining that is still firmly attached to the ceiling.

If the product could be injected (like grip fill) and also something that I could use my fingers to prod into holes (like filler) would be most useful.

What would create the best bond and be workable?

Photos hopefully help explain.

Thanks very much

.

.

 

[Tigercubrider]

Not an expert but possibly something like casting plaster applied using a big syringe like thing? You might also be best to first deliver a load of water to the crack which may stop the injected plaster drying too quickly.?
If the plaster is runny it will flow behind cracks rather than just fill from the front, it dries very quickly so apply in small batches before it goes off.

 

[SFK]

I have used this (and specfically this) 'Wickes-Instant-Grab-Adhesive-Solvent-Free' for this typoe of job.

pros
As it is not solvent based I can wipe overfill off with a damp cloth
It is cheap - but does get expensive when hole is big.
Once it drys it does glue two surfaces together making area stronger.
Nozel makes it easy to get into areas like you show.
It sticks the two sides together strongly.

Cons
It is not stick and hold, but in this case an advantage.
Being water based it takes longer to dry
Being water based it goes concave when drying so need to apply a second thin layer.

https://www.wickes.co.uk/Wickes-Instant-Grab-Adhesive-Solvent-Free-300ml/p/215368

sfk

 

[stevethespreader]

Cornices were stuck up using a mixture of screws and grade A plaster which is what the cornice itself is made of , to try and repare that i would use the same plaster and apply it using a busk also if its dropped a screw or 2 could be added, if that fails that section could be cut out a profile made and the section reinstated and it will look brand new

 

[Deleted member 292770]

Screws? theres no screws holding it up. Thats an original cove run in when the house was built.
There’s no strength in it , it’s very crumbly , like plaster of paris.
looks a bit too deformed and loose to repair.
you could remove the loose material and rebuild the basic profile slowly using universal plasterboard adhesive and use filler and sand after to get it spot on. or remove a whole section and manufacture a template to ‘run it in’ as it was done originally.

 

[stevethespreader]

Fyi they was also run on a bench

 

[rossyl]

OK.....

I wouldn't want to put screws in it now, as it might just split and break. Also, I could just screw into lath, which would be pointless.

What's stuck to thr ceiling is stuck solid.

As I said, if it comes down when building works being, so be it.

I just want to make it as secure as possible.

Casting Plaster, looks like I can only buy a huge bag.

Any other suggestions?

 

[Tigercubrider]

https://www.amazon.co.uk/Mouldmaste...ne+casting+plaster+25kg&qid=1641498147&sr=8-7

You could probably use plaster of Paris?
Hopefully someone a bit more expert in plaster restoration will chip in?
I have used casting plaster to make moulds- I think PoP is finer

 

[rossyl]

Thanks. I would like

- the strongest bond
- light in weight
- does not expand when drying

Thoughts appreciated, thanks

 

[SFK]

What was the issue with my suggestion?

 

[rossyl]

What was the issue with my suggestion?

Nothing at all.

Just wondered if when doing plaster repairs thats the best thing to use or not. Ie Strongest bond and how light it is. For example Gripfill I think would be the wrong thing for this job.

Also wondered if it expanded at all on drying.

 

[SFK]

Noted.
Shrinks slightly on drying (actual one of its issues).
Strong.
But agreed not that light.

It is the one I use for this type of issue. However agreed that it is my vote of one rather than many.

 

[Wayners]

That's running cornice.
Run in with templates by dragging along. Still done today.
Go watch on youtube and that will help you decide how to fix.
French guys seem good at it and are brought over to UK to run in cornice on hotels and stately homes

 

[rossyl]

That's running cornice.
Run in with templates by dragging along. Still done today.
Go watch on youtube and that will help you decide how to fix.
French guys seem good at it and are brought over to UK to run in cornice on hotels and stately homes

Thanks. My god it took a lot of work to put this up 100+ years ago!

 

[tell80]

OP,
i'd check that the (timber?) lintel is level and in good condition.
There's obvious hairline vertical cracks, & spelched plaster below which suggests lintel movement or pressure from the floor above?
From outside does the window opening head look level?


I'll stand corrected but I dont see anything to suggest that it was run-in on the wall.
Simple profiles like above were much cheaper to run-in on the bench or bought by the yard off the shelf.