Blue Sh*t

[J-r-C]

After being advised by a builders merchant that Blue Grit was a cheap and brilliant substance to apply to my ceilings before plastering, I jumped at the idea and bought a tub. The ceilings were coated 48 hrs ago and this morning I began plastering.......room1 the fuc*ing ceiling bubbled..then fell. There was no bond at all for the plaster......so I scraped the blue sh*t off.......is this a regular issue with blue grit???

 

[lostinthelight]

Used it over textured coated ceilings and ones that had been papered and polystyrene covered with no problem at all.What was on yours before gritting and what prep did you do ?
litl

 

[J-r-C]

As far as I'm aware it was just PB that had been poorly plastered as it was a garage. I've been converting it into a one bed flat for a mate....most stuff never done before but building is a hobby so took it on. I asked around for what is needed to skim the ceiling and was told BG was all I should use......but turned out to be a waste of bloody time! Thinking PVA would have been a better option

 

[J-r-C]

But it was also painted.....my fear is that it's egg shell......if so it's back to square one

 

[London Mike 49]

if the ceiling was plastered and painted before you attempted to re plaster it , then it could have failed because the original painted ceiling did not have a mist coat applied before it was emulsioned over.
This would mean that the untreated plaster could not absorb the emulsion properly and would peel from the ceiling over time. It just so happens that the weight of the new plaster that you applied was enough to pull the paint from the ceiling.
Blue grit is fine if the paint on the wall/ceiling is sound , but it is only as good as the surface you are applying it to.
Scrape back until no more loose stuff will come off and then plaster as normal.

 

[J-r-C]

Cheers mate. I spoke with the lad I'm doing it for and he said it was painted with egg shell....something he failed to inform me of before starting! So I can either scrape away to the original PB or re-board.....both he isn't too happy with! Or.....scrape off the new plaster and paint it! Awesome

 

[foxhole]

For the price of a few sheets of plasterboard it's quicker to board over and start plastering, problem free.