Painting - Blotchy Ceiling

Discussion in 'Painters' Talk' started by polybear, Jan 12, 2014.

  1. polybear

    polybear Member

    I've been painting a new ceiling (plastered several months ago so well dry) - I'm using Dulux Trade Supermatt White and gave the ceiling a thinned coat followed by two full coats using a roller. The finish was a little blotchy ( i put it down to poor light as a thunderstorm started half way thru and made the room very dark as I was working). So I gave it another coat and it's still blotchy - it appears ok during the day but at night it's total cr*p. It doesn't help that the ceiling has a slope on it - about 10 degrees. The paint is well stirred and thinned a little for top coating.

    Any ideas? The ceiling is 5m long by 2m wide - I'm not a fast worker (read slow...) so I'm wondering if the paint is going off too quick? What's the answer please - thin the paint some more or maybe try Floetrol (how much to use)? The same tub of paint has been used on previous ceilings with no problem, but I'll need a new tub for another coat. Thanks.

  2. DIYDave.

    DIYDave. Well-Known Member

    What type of roller sleeve are you using, eg, short / medium pile / etc

    If you're using a short pile roller and the ceiling is not totally flat, the roller can miss out any dips in the plaster and just paint the higher areas, drying to a patchy finish

    You don't always notice these dips when looking up at the ceiling as overall, the plastering may be good and smooth, but not completely flat. A long straightedge will confirm this
    If this is the case, try a medium roller or heavier
  3. mikeybhoy

    mikeybhoy New Member

    i would say its the roller or poor plasterwirk on ceiling as well. (professional painter)
  4. Boolay

    Boolay Member

    Probably not holding enough paint if your using a medium pile sleeve.
    Use a long pile sleeve
  5. plane-it

    plane-it Member

    I've noticed this recently, I was thinking that the paints these days weren't as good (low odour and safer but not as good), but may be I need to try a better rollers.
  6. joinerjohn1

    joinerjohn1 Screwfix Select

    You say the ceiling looks ok during the day, but looks patchy at night.. Could well be , there's nothing wrong with the painting, but if the plastering's not exactly flat, perhaps shadows are being cast by the artificial light (which I'm assuming will be fairly close to the ceiling. ;);)
  7. polybear

    polybear Member

  8. it may be that the board is wet behind the plaster?
    Last edited by a moderator: Feb 16, 2015
  9. supertosh

    supertosh Member

    My thoughts exactly. Had the same probs recently while dec'ing out some pods.
  10. Has is got dark brown patches on it?
  11. I suspect Poly has answered his own question - 'he ain't a fast worker...'

    Polybear, I think it should be fairly easy to see if it's due to uneven skimming which casts shadows, or due to over-rollering partially dried paint.

    I think the latter effect will be in obvious 'straight lines' with a sharper edge betwixt the light/dark patches, whereas the first will tend to be 'softer' and with probably more round-edged shapes.

    Can you take some photos in the evening?

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