Stains showing though ceiling paint

[Ergophobia]

Im painting the ceiling in my ip with dulux once, the stuff that goes on pink and dries white.

There are some brown stains on the ceiling which keep showing through after three coats.

Is there something I should be doing differently? Should I hit the areas with an undercoat?

 

[jeffb5ltr]

Yep u can spot undercoat where the stains are with a product like 3 in 1, also check in the roof what caused the stain.

Could be a roof leak or possum pee as they like to pee in the same area and do it whie standing on a beam.

 

[DaveM]

If you are getting brown stains coming through, it sounds like tannin from the roof timbers from a water leak.

First, stick your head up in the roof and check if its all dry - if not, fix the roof.

You then need to seal it, either with a sealer undercoat or with a stronger purpose one eg zinnser if its a strong stain. Just painting over wont hide it well.

 

[Pa1nter]

This is quite common and can be caused by nicotine smoke.
If it is only in a couple of areas you can buy a can of metho based spray sealer from the paint shop,(around $10-20)spray that on,just repaint the areas that need it.
If its everywhere and bad you will have to oil based undercoat the whole ceiling and recoat with one- two ceiling flat.