Skim coat falling off plaster!!!!!

[G4WJH]

Hi all...have an interesting one (or should I say something I've never come across in my 20 years of refurbs).

A relatives house, they are decorating the hall...first time after 25 years on a 40 year old property.

They called me around because they have found as they strip the walls the skim coat is popping off a couple of days after...leaving a dusty base to the face of the plaster.

They have only done below the dado rail so far and I've stopped them from doing any furtherstripping for now.

My suspicions are too long with a steam stripper.....not that they have admitted to using one. The loose skim coat is quite uniform and regulaer....and I could easily make the holes bigger. Background wise...I know they had central heating installed a couple of years back, prior to this their heating was an oven in the kitchen and a gas fire in the lounge - and did wonder if they had ramped the new found comfort up to quickly whether this may have caused a dew point between the skim layer and the plaster backing? Thoughts would be appreciated.....my concern being the whole plaster and skim has to come off if its the latter.
Cheers all.
GH

 

[1john]

Are we talking about gypsum plaster, if so what is the base coat (browning / sand or cement) or is it lime plaster over black mortar?

If it's loose then likely that it has to all come off, if the background is sound though it may just require a PVA session and a skim, or a tight bonding coat and then skim.

Need a little more info and/or pictures really.

 

[jrplastering]

pics would b helpfull it could have been skimmed onto distemper and paperd over for this very reason that they found it wassnt takeing properly and was trying to hide it, post some pics mate and we will see what we can do

 

[Richard C]

Interesting theory about the dew point under the skim but, assuming it’s a cavity wall property, I doubt ramping up the new central heating had a lot to do with it. Many things can conspire to cause failure as already stated but consider that 40 year old plaster has the right to be a little tired now & the basic materials used back then are not as good as modern equivalents (he says bravely ). The skim in every room of my own 40 year old property was mostly blown as was around 40% of the base coat, in many rooms there were some pretty substantial settlement cracks on the internal walls to boot. I had to strip most of it, metal lath reinforce the cracks & re-render along with a complete re-skim of the walls & beautiful Artex covered ceilings in the entire property.

You do need to be careful with steamers, if you leave it in the same place too long, the skim overheats & you can actually hear it popping off the base coat; warm water & a good soak is still the kindest method IMO.

 

[jrplastering]

same here rich i never use a steamer to strip wallpaper i usually take off the top layer with a scraper as more often than not it comes off easy anyway. then use a roller and a bucket of water, one coat quick fag, second coat, cuppa. then it will fall off

 

[roughcaster]

warm water & a good soak is still the kindest method

Absolutely Rich'!!! Nothing like a good bath after a hard days graft.

 

[Richard C]

warm water & a good soak is still the kindest method

Absolutely Rich'!!! Nothing like a good bath after a hard days graft.

As hot as you can stand it & covers the overflow & when you slide back in it; + a good dose or Radox, a bottle of Sauvignon Blanc or Chablis (sorry an unforgiving prostrate forced me to give up beer years ago) & either my "Scottish Moors" or "Wellbeing" CD piped to the bathroom speakers. I sometimes think of lighting “her” aroma candles but that’s probably being a bit too much of a woosy. I’ve always been a shower man but, as years increase & take their toll, I find forty minutes in there & you don’t really give a ****e how much you ached or who's upset you.

 

[jrplastering]

run a bath and stick micheal buble on and youve got your self a buble bath haha .
not me though shower man in afraid cnt stand a bath, your sitting in your own dirt

 

[Richard C]

not me though shower man in afraid cnt stand a bath, your sitting in your own dirt

Showers were always me for the same reasons but just you wait till you get old . The pleasure & relief of a 40 minute soak in hot water is such that you won’t mind your own dirt; unfortunately, the next stage is probably incontinence pads

I always cold shower after anyway as it’s the only way I can stop the sweat & wake myself up again

 

[G4WJH]

Hi Gents, many thanks for your input. I took a couple of photo's on my mobile at the time...just need to figue how to upload.

To describe the extent of degredation, the skim comes off in nice shiney patches the size of a beer mat (funnily enough), it has a very powdery backing to it. It seams the skim coat has 'popped' from the original face of the plaster.

The remaining plaster is secure to the wall but is very powdery to touch. It is a light cementatious grey, and given how powdery it is I'm conscious of its removal given how dusty an opp this would be - especially given how long plaster dust stays in the air.

On initial inspection I'd have said damp has got in and has since dried out (hence my dew point theory) hence the plaster has lost its adhesion properties with the skim crust - but its upstairs, in the hall...on two internal walls. A quick tap around other walls in the house and they seam solid.

Very weird!

Am not sure what method of fix/remedy can be used to intergrate the exisiting powdery surface after the removal of the loose skim coat (ooh....gap in the market...dragons den here I come! "I need half a million to develop a powdery plaster application which I'd like to think about in the maldives........").

Its an early 1970's building but in my experience either the plaster seems to stick like 'ess haitch one tee' or comes completly away (with ease) with this period of property....but at the end of the day I suppose it depends on the chap doing the mix at the time (bet he's retired now!) and if it was a really cold day.

Cheers

GH

 

[G4WJH]

....and I'm a shower man...just getting round to installing one of these over-heads with the detachable head peice......I fulfilled a lifes ambition of putting in an extra deep bath 3 years ago so I could sit and wallow (covering my tummy).....yet I'd be damned if I ever get an hour to dwell on having a bath.....and have yet to actually have a bath in it....but the kids love it (taught them to swim in it!). Nothing like standing with a shower falling onto your head for 10 mins or so.....thinking about getting a nice comfy chair for the occaission!
GH

 

[1john]

You could try brushing the wall down and applying some diluted PVA to a test area, leave it dry over night and see if this has sealed it, if it does then do that to all the walls and then the next day apply another coat of PVA and skim over when tacky.

Shower for me every time by the time i can run a bath i'm on and out the shower.

 

[ajrobb]

1.8m double-ended deep bath, missus and bottle of something cold...

1.7m double-ended bath was too small for two - hardly room for water and got cold too quickly.

 

[1john]

1.8m double-ended deep bath, missus and bottle of something cold...

1.7m double-ended bath was too small for two - hardly room for water and got cold too quickly.

The extra 4" pleased you both then!!

 

[spc]

i know its a bit grim, but taste the back of the skim that popped off. it could be slight suphate or salt retention