Coving adhesive failure after 5 months

[mistercoffee]

Hey all,

We had two rooms coved 5 months ago. Today, a piece of coving along one wall came down. I noticed a large crack had developed so I poke it a little bit to see if it had some play. Lo and behold 5 minutes later it came down. There are cracks developing elsewhere in the same room. The other room so far doesn't show any cracking.

Now, both rooms had just been plastered. The difference is that the failed room had been fully emulsioned when the coving went up. The good room had only had a mist coat. The coving guy (old and experienced) knew exactly what the situation was and was confident all would be well.

You can see in the photo that there is next to nothing of the adhesive left on the wall and ceiling. The bond has completely failed in my eyes.

Tomorrow he is coming round to take a look at it and he says he'll sort it out. I need to decide my position on what we should do. We have tonight moved out son out of that room as we don't want more coming off on him in the night. I am mindful to have the whole room done again, despite the agony of repainting the new coving and walls.The guy hinted that screws may be needed. That might help, but I really feel like thats a secondary to the adhesive actually bonding, which it clearly hasn't. What should we/he have done differently?

 

[mistercoffee]

Just to add that I doubt this is due to movement in the walls/ceiling as behing the fallen coving there are no cracks at all.

 

[CJRatch]

Are we talking plaster coving not the lightweight stuff?

If you read the instructions on pretty much all coving adhesive it doesn't recommend fitting to a decorated surface as it won't bond. If you insist on trying score both the wall and ceiling surfaces to provide a key for the adhesive to grab to.

From the looks of it this wasn't done but even if so with the heavy plaster coving even scoring isn't a guarantee.

Your more likely to get away with this method if using the lightweight stuff.

Coving should ideally be fitted to fresh plasterboard or skim.

I'm not a pro just coved my whole house so have some experience.

 

[mistercoffee]

Thanks for that. The stuff he's used is Gyproc Cove 100, doesn't feel that heavy...

We'd already painted the room by the time he'd come to fit the coving unfortunately. He's an experienced guy and was recommended by our builder. Neither raised the issue with the room being painted

Obviously we can't go back to plaster skim now, so we need to work out what the best approach is

 

[Wayners]

Rub finger on cut coving joint and if chalky like plasterboard you know it's the standard cove. Made from plasterboard.

There are a few adhesives on the market for coving plus some use things they should not.
On sites board adhesive is used (for dot and dab plasterboard to walls) but this will fail over some emulsions. It needs a primer to aid the sticking. Says so on instructions.

Wickes cove adhesive seems its just board adhesive in smaller bags.
I use gyproc adhesive as best stuff.
I have used easyfill to stick cove but a little soft but it says fine for coving.
You need to find out what it was stuck with. Then go read the product data sheet online for using on the surface.
I'm forever pulling coving down that's been stuck with artex or tile adhesive that's coming away. Scratch surface, prime surface. Use correct adhesive and coving is welded on.

 

[mistercoffee]

I'll ask him when he visits tomorrow thanks