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Painting & Decorating

How to seal plaster before using the anti mould paint

I had some mould (due to condensation) on bedroom wallpaper so I have removed all the wallpapers. I am planning to paint the wall with Ronseal Anti-Mould Paint instead of using wallpapers. Also, bought a dehumidifier to fix the condensation issue.

Ronseal website suggests I need to seal the plaster before using the Anti Mould Paint for a newly prepared plaster. In my case, there were wallpapers on the wall so I think it still applies to me.

Can you please suggest how to seal plaster? If you can suggest any available products then it would be very useful.

EDIT: I talked to Ronseal, they suggested I need first coat of anti-condensation paint and followed by anti-mould paint. They think I do not need to seal the wall. I think I am more confused now :S

5 Answers from MyBuilder Painters & Decorators

Best Answer

Hello, you have taken the wallpaper off your walls good. No need to seal the plaster because it has had wallpaper on them, and adhesive on your walls. Wear a mask and gloves and add mould resistance from ronseal.
Leave to dry for 24 hrs 1 to 2 coats of ronseal.
After that I would add 1 coat of oil base undercoat on top of your affective area only please let this dry. After this you can repaint your walls.


Answered 6th Mar 2020

Hi.take the wallpaper off,I prefer to use undercoat oil base 1 or 2 coats and after I will put back the wallpaper, do one more coat of undercoat and it s a brilliant job,if you want to do it quick I will use zinsser 2 or 3 coats, everything depends the damage


Answered 13th Mar 2020

On cold surface you can apply any anti-condensation paint it won`t work, because thin layer of paint not gone stop thermal bridging.
Anti - mould paint probably will do the job as primer or undercoat.
If Ronseal not gone work you ca try to use another products like Zinsser.
Or for priming can be done with PVA and water about 1:4 ratio
Recommended to try on small area first.
Hope it helps.
Many builders has different opinions :)


Answered 6th Mar 2020

To do this , clean surface thoroughly with zinsser universal degreaser and cleaner, then spray zinsser mould killer and remover directly onto the areas affected. leave to dry 1 day then apply zinsser perma white x 2 coats.


Answered 13th Mar 2020

I would recommend that you clean surface with mould remover and then use Primer/undercoat or Zinsser BIN.
Hope this will help.


Answered 13th Mar 2020

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