plaster dropped off when papered Ask your questions and find answers on many subjects relating to plastering and dry lining

[armytouch]

Hi plastered wall about 3 month ago,all seemed fine,however when put wall paper on wall,the paper started bubbling,so removed paper however plaster as come off with paper,what as caused this to happen.
It was pva before plastering.
was it caused by plastering or papering.
thanks

[armytouch]

Hi just found out that the decorator pva the newly plastered wall before papering over it,could this cause the plaster/paper to bubbly and peel away from wall,or is it the plasterers fault?
I know the plaster put pva on wall before he plastered it.
Why as this happened.

[armytouch]

Hi,got little bit more information about wall hopefully will shed some more light on situation.
Wall was plastered about 2 month ago and left to dry,no problems,no shagging well none visible.The wall in question was plastered at same time but 1/3 of the wall was thinner because of the levels of the passage,the other 2/3 had to be thicker to level out the wall,the thinner bit is still about 5mm.
The decorator came to wallpaper,he unibonded the wall first left it to dry then started wallpapering,however when he came to the thinner part of the plaster a bubble appeared,on removing the wallpaper the plaster came off.the 1/3 of wall thinly plastered came off,we washed the other side with water and it still seems firm against wall.
The decorator said that the plaster wasnt pva before plastering but i know it was and why was it just the thinner part that came away,if it wasnt bonded wouldnt the lot come away.
The plasterer as said that the decorator shouldnt have unibonded the wall,and the reason its the thinner part as come away was because the unibond as soaked thru the plaster and reactivated the pva below and weakened the plaster.
Who is right?

[tubbs]

i'd agree with the plasterer pva on new plaster can react with pva under a thin coat of plaster. decorator should have used plaster primer. nearly all new wall paper will bubble when first put up this is common, the mistake is taking the paper of the bubbles will fatten out when the paper dries. the decorator should know this.

[armytouch]

hi, thanks for the information the plasterer said the decorator shouldnt have used unibond and also he shouldnt have removed paper after,but the decorator did,the actual wallpaper which was imported from france cost £200 and was destroyed.
So in your opinion it was the decorators fault,he did seem little nervous when blaming the plastering who i think is going to ring him up and have a word.
The plasterer didnt charge us for the work maybe he will be sending the decorator the bill,maybe we should send him a bill for the wallpaper?
I appreciate your help.
Hi is there anyone else with any views on who is to blame.
Do you agree its the decorators fault or plasterers?

[armytouch]

Hi again the story goes on.
The plasterer rang the decorator to tell him the bill for the job would be sent to him and to explain about the plastering.
The decorator claims it was his job to unibond the wall before wallpaper,and that he does it on all fleshly plastered walls.
He claimed to be a member of the federation of painters and decorators so the plasterers going to get intouch with them and see what advice they give.
The plasterers upset because the decorator blamed him and tried to tarnise his reputation, aswell as having to do the job again.
Do you think the plasterers right?

[cabby]

what is the plaster u put on the wall and what was it put on is it finish on plaster board or on an already plastered wall ?
was there bonding put under the finish coat this info would help

[armytouch]

hi,like said in initial posting the wall was pva by the plasterer before he started,it was a painted wall he plastered over not plasterboard. He used multi-finish plaster and put on 2 coats.
Spoke to some other decorators and they said that it shouldnt have been wallpapered over so early and definately not unibonded over fresh plaster.
Please leave your opinions.
The Plaster seemed to be well stuck to wall until decorator came along,cheers tubs for your reply.
So what happens when unibond is placed on over fresh plaster which was unibonded before starting plastering?

[cabby]

i would never just put finish on a painted wall i would put on a coat of bonding first i dont believe finish would ever have enough grip on its own
i asume he keyed up the old paintwork first ?
some times it seems like its well on but it can pull off when it starts to get hard ive seen whole ceilings just drop
this may not be the case in ur case but it helps to know all possable problems

[armytouch]

Hi cabby, think you have misunderstood all the topic, the plasterer pva the wall before he put any plaster coats on the wall.
It was only after the decorator applied the unibond then wallpapered it that the thinner coats of plaster started comming away from the wall.

[armytouch]

Hi please send your opinions on why this happened,thanks

[rosebery]

I'm only going to offer this opinion to help you understand what has happened. I'm not offering it with a view to it being used to bash either tradesman around the head nor to be used in any way or form if there is further action whatsoever relating to this incident. Please understand that implicitly.

First the plasterer. Yes I would expect a plasterer to PVA a rough brick wall before plastering. The purpose of this is to prevent the wall sucking all the moisture out of the plaster too quickly. If he PVAd straight over paint then he has created the first problem especially if he didn't key it as has been suggested by another poster. Did he carry out the "tape test"? That is to say a piece of sticky tape pressed well onto the paint - leave for 30 minutes. Pull it off. If the paint comes too then the paint needs to be stripped off.

If he PVAd straight over the paint then of course the plaster is going to come off. However dry the PVA was before plastering the moment the plaster hit it it became live again with the result that there was little or no adhesion of plaster to paint.

2nd the decorator. First of all under no circumstances should PVA be used on new or old plaster before papering. Perhaps he trained on one of the outer planets? PVA does nothing for assisting wallpaper adhesion and because when it gets wet it goes live again the opposite can easily happen. New plaster should be sized either using a proprietary size or a weak wallpaper paste (iro 25 - 30% more water than the actual papering mix).

Where the plaster was especially thin it's more than likely that the decorators PVA application soaked through the plaster to the PVA layer beneath on the unprepared paint. The end result was a layer of wallpaper barely sticking to a layer of plaster by now failing to stick to the paint underneath. This manifested itself as the bubbles. He should also have waited to see whether the bubble shrunk back as the paper dried.

Any decorator worth his salt should always check the entire surface he is about to paper to see if any of it is "blown". If it is the section concerned should be removed and patched first.

Frankly I would suggest, from the information you have provided which is all I have to go on, that they are both at fault for inadequate preparation (possibly but by no means certainly on a "get in, get out quick and get paid" basis), both have been caught out and both now trying to blame the other. You'll get nowhere playing one off against the other and if you are seriously after redress from one or both then you should either consult your solicitor or your local trading standards.

Cheers

[armytouch]

Thanks rosebery,
I have no intention of using any information against plasterer or decorator leaving that to them,but like to know myself why this actually happened and its information other readers may learn from surely thats what the site is for.
I didnt actually see the plasterer do a tape test before applying the pva or plastering but when he came back after the decorator he remarked and showed that none of the paint had peeled away from the wall it was still all intact plus surely if it was the plastering over painted wall then the whole plastering would have come off not just the thinner part?
I hope thats the case because he just pva over the wall again and plastered it,he didnt charge us but said he would be claiming the money off the decorator,and we should claim the cost of the wallpaper which was £200 off him.
I think the plasterer was more upset about the fact that the decorator blamed it all on him not pva the wall,when i know for a fact he did,i saw him,than the fact he had to come back to the job.
thanks again,if you have any more oppinions please send.

[armytouch]

Hi, well its been about 2 month on from plasterer coming out again and plastering wall that was dropping off after decorator came to hang wallpaper and applied unibond to new plaster which came away from wall when he started hanging wallpaper, i was told by the decorator that the plasterer cant have unibonded it to wall,but i know he did. I have since been told the decorator shouldnt have unibonded new plaster as when soaked through plaster it reactivates the old bond keeping plaster to wall,i was also told that new plaster shouldnt be applied straight to new plaster for approx a year.
The story continues, when the plasterer did come round to patch the part of wall where plaster had come off he did ask if the decorator had applied unibond to other parts of new plaster,i told him he had so he told me to wash wall to try and stop the unibond soaking in under plaster,this i did, the plasterer also told me to apply a coat of 50-50 paint water if wanted to hang paper, however when i have painted wall there are areas of plaster that are coming away from wall, i have been intouch with plasterer and he said that patches of unibond must have soaked through.Does this sound right?