Suspected bonding coat failure?

[LMJ90]

Hey guys, and girls! Though I've spent quite a bit of time browsing this site (which has been invaluable on more than one occasion by the way, so a big thanks in advance there!) but this is my first post on here .

We've just had a multifuel stove installed in our 2nd reception room. Tidy job, and overall very happy.

My question concerns the plaster. Fair bit of hacking was done to make a recess for the stove, and the bonding coat had separated from the scratch coat. So I decided to hack it back further until I found sound material. Anyway, that's since been done - and it seems to be loosening yet again around these freshly cut areas. I'm suspecting that the bonding coat never adhered well to the scratch coat when it was done some 30yrs ago. Whats the best step to take from here, I'm thinking dab / plasterboard the whole face of wall (remove all old plaster / bonding). OR do I chase it back some more, seal scratch coat, Sand / plaster mix and skim the whole lot? I'm leaning towards PB option personally, as I'm predicting (with my first option) that the joint between old bonding coat, and my sand / plaster mix might crack with the changes in temperature?

Sorry for the essay, some pictures to follow.

Thanks! Llyr[code:1][/code:1]

 

[LMJ90]

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[LMJ90]

Anyone?

 

[Pigeon85]

Personally would knock off the plaster a board it as you may well end up taking most of it off anyway also something you could do easily yourself. Give you the opportunity to chase that socket into the wall aswell- just a little bonus

 

[LMJ90]

Exactly my thoughts, every time I chase back further, it seems to blow off the wall. Dab board it is. And its getting re-wired anyway, so yes, as you say - a bonus. Thanks, just wanted to know if I was on the right track.

Small question - how do I go about scrim taping the ceiling line? As its artexed atm, (which doesnt bother my Mum that much, its the 90s stuff / pattern). So Im wondering what I can do there...

 

[Pigeon85]

I'm not a pro plasterer but as taping would be difficult I believe this is the thing to use http://m.wickes.co.uk/mt/www.wickes.co.uk/invt/227979?un_jtt_redirect maybe a pro will come along and clarify or indeed give more opinion and advice

 

[LMJ90]

Ideal! Thanks!

 

[1john]

Dont scrim it, just get your boards tight to the ceiling.

 

[Pigeon85]

Dont scrim it, just get your boards tight to the ceiling.

if they are tight would decoraters caulk be sufficient to tidy the corner

 

[1john]

After skimming and a mist coat you may see a hairline crack which caulk would sort out. apply it, smooth it in with your finger and wipe it over with a damp sponge.

 

[LMJ90]

Ah ok, cheers! Being the wall where the stove is, it'll crack a bit inevitably Im sure!

 

[1john]

The best preventative measures you can take are to apply a solid run of board adhesive along the top and to let it dry out properly before using the fire, bearing in mind the dab could be an inch thick, the plasterboard another 1/2 inch and skim, suction into substrate etc it could well be 2 or more months.

 

[LMJ90]

Right ok, that'll be worth considering then! I was thinking of sealing the existing gypsum(?) scratch coat with PVA, then dabbing onto that. I believe a solid bead on the ceiling line is for fire regulations isn't it? Thanks again!

 

[1john]

You dont need to seal it for dab, its a good idea to do a solid line at floor level too for skirting fixing, although I tend to just stick the skirting on with grab adhesive to save filling screws and sanding. Still helps with that too though.

 

[LMJ90]

Yeah I knew about the base bead too, and around sockets etc is a good idea. I hear what you're saying about grab adhesive, use it often myself (Siroflex), but I found that some torus skirtings started cupping off the wall slightly in another room (which was a pain!) Just need to get the house re-wired first, then it'll be done asap!