Skimming over existing plaster

[topgun]

I intend to skim over existing plaster, is this acceptable? What will i need to do to key the new skim in?

 

[Swiss Tony]

I had my whole house skimmed by a proper plasterer 3 years ago.

Some areas are not keyed as when you tap the wall you can hear the difference.

So i assume that he didn't do anything to key any of it in.

Suggest that you scrape the walls with a block of wood with some nails in it to scratch the surface, and pva the walls too.

I am now using a Polish plasterer to do some work, but I can't understand a word he says so no use asking him! Everything I ask him he just nods and says yes.

 

[jbonding]

I had my whole house skimmed by a proper plasterer 3 years ago.

Some areas are not keyed as when you tap the wall you can hear the difference.

So i assume that he didn't do anything to key any of it in.

Suggest that you scrape the walls with a block of wood with some nails in it to scratch the surface, and pva the walls too.

I am now using a Polish plasterer to do some work, but I can't understand a word he says so no use asking him! Everything I ask him he just nods and says yes.

He must of applied some kind of key or none of it would of stuck.

pva is sound also Bond-it
Let us know how it goes with this bloke who cant understand you

 

[Blaster]

spoke to plasterers on subject they say pva 5:1 apply to area allow to dry apply same just before skim allow to go tackie then skim.......hollow knocking sound means original wet line delaminated from wall........or it was dry lined

 

[Richard C]

Blaster has it exactly right with the approach for a skim coat; the only thing I would add is to stick some glass fibre reinforcing tape over any visible cracks to stop them showing through & certainly follow Tony’s advice with the nail board if the wall has been finished in Vinyl gloss emulsion (causes all sorts of problems that stuff)!

I've got many hollow soundings on the original 1/2" render & finish skim coat in my old property & have stripped back & repaired some of the larger areas where there is an obvious problem. I’m sure a lot of it's been 'blown' for an awful long time so I decided to leave well alone where it still seems OK; otherwise I think you could well end up pulling the whole lot off & having to start again which ain’t cheap & certainly not easy if your just learning like me!