ceiling mark

almeria1

In my son's flat the bathroom has what I assume is a mark from when a water leak has occurred above the ceiling. I have now been round several times this week and painted over the mark and it is still visible- a bit fainter perhaps - but it can still be seen when you look up. Any tips from anyone who has solved this problem before ?? thanks

Myser

Are you able to lift up the floorboards above the ceiling and check if there is still a leak?

almeria1

No not leaking now appears to be an old mark from previous tenure. I did check the loft - he is in upper flat and there is no water tank there so cannot fathom what caused the mark !!

theGrinch

you try a gloss or a stain block over the stain and then paint over with the final colour.

uk_messer

Semi agree with thegrinch but it's not important that it's gloss, just that it should be oil based, not water based. So a water based gloss would not work. Best to use an oil based primer or undercoat so you have a matt finish to paint on.

keystone

You are using waterbased paint over a waterbased stain. The new wet paint is reactivating the stain and it is leeching through the new paint before it has a chance to dry.

A proprietary stain block or spirit based undercoat (if you use gloss you will be able to physically see it afterwards although the stain will be gone) should be used.

Then repaint the whole ceiling or you will see a patch.

Cheers

laurel7172

Ceiling stain/upper flat/no water tank? You might want to have a look in the loft while it's raining...