Thin plaster layer on top of paint

[Thunderette]

Hi guys,

Was referred to you from the decorating forum.
Have been removing wallpaper when encountered a purple vinyl-like layer underneath, which most of it came of with the wallpaper.
Underneath the purple is a 1 millimeter layer of plaster, and in a little whole in it I can see red paint.

Untitled

• Thunderette
• 1 May 2011
• 2

Any ideas what we have here? Should we do something with the thin plaster layer before painting on top? Is th purple vinyl-like stuff there for a reason (i.e. something to do with damp)?

Have never done DIY before so please use words I'll understand
Thanks!
Thunderette

 

[NickB_99]

Was referred to you from the decorating forum.

Nice we're getting referrals now - welcome to the plastering forum

Any ideas what we have here? Should we do something with the thin plaster layer before painting on top? Is th purple vinyl-like stuff there for a reason (i.e. something to do with damp)?

It sounds like a previous skim was put over the red emulsion, then a vinyl/shiny purple emulsion on top.
I'd suspect nothing to do with damp.

How solid does the plaster on the wall feel - if you tap it with a knuckle does any of it sound hollow or does it all sound secure?

 

[jrplastering]

sounds to me like your house had a reskim some time ago then the plaster was painted with purple viynal then paperd because they realised the purple looked rotten.
how good is the purple layer under neith the paper.
if you want perfect walls to finish paint with ease youll proberly do best to replaster the walls/ceilings what ever you need doin.
if you get a plasterer in to do the job he might tell you that he will apply a layer of pva then replaster, but this wnt be a strong enough key for the plaster to bond to on viynal paint.
it costs more but you need to use some thing called thistle bond it or wickes bonding agent, this has a fine grit in it and provides a mechanical key for the plaster to bond to.
oh and it has to be dry before he skims onto it usually 24 hours but leaving it over night should be sufficiant.
out of interest the peice of plaster you picked off to reveal the red paint, how easy does the plaster come off of the wall. just wondering how well the reskim has bonded to the original substrate.
hope this makes sense for you if not let me know and ill try dumb it down a bit

 

[Thunderette]

Thanks for the warm welcome!

It feels solid, although there're a few cracks, and a couple of little bits have fallen away (that's how I know about the red behind...)

I'm from a very dry country so get stressed by any possibility of damp - glad to here it's probably not the case

Cheers newbee!

Thunderette

 

[jrplastering]

sorry newbie i think i started my reply the same time as you but im distracted by the snooker and it took me ages to write my thoughts haha.
ya beat me

 

[NickB_99]

sorry newbie i think i started my reply the same time as you but im distracted by the snooker and it took me ages to write my thoughts haha.
ya beat me

No worries. Just glad I was on the right lines.
Hate it when I post in parallel & have it wrong!
Also like to add -

It feels solid, although there're a few cracks, and a couple of little bits have fallen away (that's how I know about the red behind...)

JR's description is a good and tells you the detail you should know if you wish to get a plasterer in to cover the stripped walls & get a very good finish.
I would also add (as you say you have a few cracks) that they need to be dealt with.
In this case the plasterer should be covering them in something called scrim tape. See the wiki for a picture. This reinforces the skim plaster in this area.
If there is no hollow sound as you say, then the plaster underneath is probably sound. (It prob also shows you have an undercoat plaster there rather than plasterboard). So the cracks you have are probably minor and the scrim tape under a new skim will sort them.

I generally prefer the more thorough/long lasting solution - however, if budget dictates a more economical fix.....(sorry guys )
Use easi-fill to cover the bits you've pulled out and these can be sanded
to a flat finish against the existing.
I've also in the past put some scrim tape over just surface cracks and applied a single coat of easi-fill applied with a small plastering trowel over these (about 10cm wide) and sanded/blended in with existing. I think it gives a bit of a stronger finish than the filler alone. Mind, you have to be careful not to get it too proud!

 

[Thunderette]

Thanks jr, think i got it... the purple vinyl (?) layer has mostly come off with the wallpaper, so we're peeling it away (with one eye on the Wizard of Wishaw).

 

[jrplastering]

judd to win

 

[jrplastering]

and sorry vinyl my spellings not up to much i tend to rush sorry haha.
once you have the vinyl layer off then you should be able to just pva and reskim but as newbie said have a look and a think about the cracks and hollow spots, they will need tapeing over the cracks or pulling out and filling in with easy fill (for the diyer) or plaster then reskim over the top of the lot for the plasterer. if that is your intention of course.
i know im biast being a plasterer myself but reskim will give you a lovley finish (provideing you get a good spread) if you decide to reskim try to get a recomended tradesman mabey ask to see his work, we see far too many people on this site that are left in trouble after a cowboy has been in and lashed thier walls up.

 

[NickB_99]

judd to win

good call

(sorry OP)

 

[Thunderette]

Many thanks to both!
(All the best to Judd but Higgins is my man)