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Help Required


(John Watson) #1

Hello everyone,
I wonder if anyone can help with a minor problem I have with one small area of my bathroom ceiling?
We had the bathroom refurbished back in February this year and this included skimming the walls and ceiling. I then mist coated them and filled them using Prestonett ready mixed filler before sanding and applying two coats of Little Greene Intelligent Emulsion 223 Shallows to two walls and the ceiling using Wooster Pro Dooz medium pile rollers in both 9" and 4.5" sizes. However because of the size of the gap between the loft hatch trim and the wall this area was painted by brush - probably a Proform Picasso.
Much to my dismay, last week I noticed that this area is flaking (see photo). I have checked the area in the loft above the damage and it feels dry but there is a cold water feed pipe which is not insulated (it will be) and I wondered if at sometime there has been condensation on the pipe which has dripped off and caused the damage.
What do you think is the cause and what is the best way of re painting it?


(tehomas ) #2

dose it look like any of these ?
https://www.google.co.uk/search?q=efflorescence+on+plaster&source=lnms&tbm=isch&sa=X&ved=0ahUKEwiPrbOB8qrXAhWEtxoKHZLBCWwQ_AUICigB&biw=1280&bih=867


(John Watson) #3

Thanks for your reply.
I think that you have identified the fault, here is a closer view.


Thankfully it is only about 2ft long and in an area that is not prominent.
Do you have any recommendations about how to deal with it?


#4

Hi
The link above is for efflorescence, which is salts in masonry. Never known a ceiling to have a problem with efflorescence. You would see crystallisation and blown plaster.

I don’t use Little Greene for clients, but I do use it in my own home. After a year I had paint cracking and peeling. The 2 walls concerned were cold and subject to moisture.

I’ve sanded back, applied a thin coat of paint, filled and then applied a full coat of paint. I waited for each coat, including filler, to dry fully before further application.

Couple of questions, have you solved any moisture issues, plus humidity in bathroom?
What was the old surface that was plastered over. I am trying to resist asking but why filling after new plastering?

Ceilings in bathrooms I use Zinsser Perma-White without any peeling or mould etc. Some of the painters on this site might use classidur universal primer, which by all accounts is a superior product. Not suggesting that Little Greene might not work but never had a problem with Perma White


(tehomas ) #5

hi howzz efflorescence can occur in a ceiling if it has been newly plastered over larthen plaster in a period building .


(Andy Crichton) #6

I think painting over old paste could produce that result.

Re Efflorescence, it is the salts in an alkaline substrate drying out and crystallising on the surface, so perfectly feasible on gypsum plaster. However it tends to be white powdery at first and on the surface. If it were left a long while to develop it may push off the paint. I saw someone posting elsewhere online to brush off (good idea) and repeatedly wash the efflorescence off. Washing is about as bad an idea as I can think, as you are feeding the substrate with ever more moisture to dry out.


(John Watson) #7

Thanks for your thoughts chaps.
I’ll brush off the dust and catch it in my new Festool ctl midi (show off!) - that’s the trouble with learning new techniques on here.
I’ll then lightly sand it and try a couple of coats of Little Greene and see how it goes
@Howzz I’ve got to get a length of 22mm pipe insulation this week and fit it before I start the remedial work. I don’t see any evidence of general condensation in the bathroom indeed I’ve gone to town on countering that with an extractor fan with humidity control, replaced the plastic hit and miss vent with a swanky stainless steel one immediately above the shower and we also open the window when showering. When I leave the bathroom I leave the door open to create a good air flow to the window and eventually close the window. Regarding filling after new plastering -good point; I employed a good plumber who has worked for me before and the lads did a good job but being a retired mechanical engineer by trade and profession I’m somewhat of a perfectionist so I finish up undoing the bits I don’t like and doing it myself. I thought that I had written a reasonably detailed specification but you cannot cover every last detail of workmanship. I found out at the start of plastering that you cannot use the stainless steel beads with gypsum plaster that I specified - I tried my best but failed!


(darlic) #8

Hi folks whats the best paint out there for high condensation areas?would rubberized coating help?or is it a case,a very high condensation area with no venting theres little hope for anything?