plaster problem

[penry]

I recently moved to a fairly new house.I wallpapered the walls but the plaster especially down the seems is coming clean off the boards behind.There is no sign of the plasterboard being damaged at all.I know you dont need pva for plasterboard so any ideas on whats wrong.Next door no problems.

 

[Third_Eye]

Yes, you are "correct" about not needing to PVA prior to plastering over gyproc. However, that is what we are told, but there are loads of flaws with applying plaster directly on to gyproc ! Is your gyproc Ames Taped or Plastered ?

 

[penry]

how do i tell.What is the difference.I thought plaster board was plasterboard.

 

[Third_Eye]

If your walls are emulsioned then it is difficult to work out whether they are Ames Taped or Plastered. Is there evidence of Pink Plaster where emulsion has been damged ? or is there evidence of Light Grey/White filler at the Jiont Boards of the Gyproc ? The thing about Home Builders these days is most of them are PLC and by this, if they can save money for there Shareholders, then they will use the cheapest product on the market of which they can get away with ! One example is 'British Gypsum Gyproc' make the best Ames Taping materials and the worst is Lafarge. British Gypsum Gyproc being the dearest and Lafarge being the cheapest.

 

[penry]

Alright cheers for your help so far.I have spoken to someone in the plaster boarding trade.A quantity surveyor who thinks that the paste used to fix the wallpaper to the wall has been made too strong.especially as the plaster seems to be coming away more down the wallpaper seems where extra paste is usually added.This is then reacting to the skim on the board.Does this sound realistic.

Cheers for your time.

 

[Third_Eye]

The Decorating Trade getting the blame again, lol. There can loads of reasons why it is happening. Though i can guarentee you that the paste is not the culprit. Yes, the paste is causing it but there is something wrong with either the Gyproc or Ames Taping materials or Plastering materials or if it is the paint that is coming away only then the first coat of emulsion has not been thinned enough/to much. Sometimes with cheap materials in relation to Gyproc then the top layer of paper can blister from the plaster inside the Gyproc. Sometimes with cheap materials in relation to Ames Taping then the second coat of filler can lose adhesion to the first coat. Also, sometimes when plasterers are plastering over gyproc then the second coat of plaster can blister/lose adhesion from the first coat of plaster. However, these flaws only become apparent when these walls are wallpapered with thin, medium or thick paste. I have personaly experienced this myself on many occasions. Though everytime it happens the Decorators get the blame. It seems to me that your walls are Plastered (not Ames Taped) and the second coat of plaster is loosing adhesion to the first coat of plaster. Bassicaly this should not be happening. The causes are either cheap gyproc (that amazingly has passed British Standard) or the first & second coats of plaster were applied on different days or it was very hot weather whilst plastering.

 

[penry]

Ok thanks third eye your help is much apprecciated.Ill take the plaster back pva and plaster again. Cheers again for your time.