Used to work with a plasterer a few years ago who would dot and dab over anything from bare brick/ block/ concrete, to existing painted plaster /stripped wallpapered walls. A couple of coats of watered down PVA and he was good to go. Always went along with this as he was a pro, and seemed to be what everyone else was doing.
Recently went back to a properly he did maybe 8 years ago where 2 walls are not massively loose, but have developed a slight rattle /bounce in a coulple of spots. Not the end of the world, drill a few holes and spray some foam adhesive in there, job done.
From the areas i was able to investigate, the dabs are stuck solid to the back of the board, and the original plaster wall is still sound. It's as if the adhesive has just come away from the original plater in a complete piece, almost like when you bang adhesive out of bucket. I'm thinking old paint or wallpaper paste at fault, but shouldn't the PVA help this?
My question really, when discussing this on another job, their plasterer seemed shocked at the thought of D&D over existing painted or (stripped) wallpapered plaster. Said 100% chop off old plaster everytime. I agree thats the best way when you can, but i was under the impression a lot of boarders are just dabbing over existing sound plaster?
Thoughts?
Recently went back to a properly he did maybe 8 years ago where 2 walls are not massively loose, but have developed a slight rattle /bounce in a coulple of spots. Not the end of the world, drill a few holes and spray some foam adhesive in there, job done.
From the areas i was able to investigate, the dabs are stuck solid to the back of the board, and the original plaster wall is still sound. It's as if the adhesive has just come away from the original plater in a complete piece, almost like when you bang adhesive out of bucket. I'm thinking old paint or wallpaper paste at fault, but shouldn't the PVA help this?
My question really, when discussing this on another job, their plasterer seemed shocked at the thought of D&D over existing painted or (stripped) wallpapered plaster. Said 100% chop off old plaster everytime. I agree thats the best way when you can, but i was under the impression a lot of boarders are just dabbing over existing sound plaster?
Thoughts?