How to paint soot-covered wall and ceiling?

[Cory12]

I am in the process of repainting a bedroom that has soot from candle covering the walls and ceiling.  When I first tried to clean up, I made the really bad mistake of wiping with sugar soap. Bad move!!

Having done a bit more research, the advice that seemed best was 1: vacuum with brush attachment (you can imagine doing that to the entire room), 2) clean with magic eraser 3) wash with degreaser / sugar soap.

I have now cleaned it as per, but there are some grey smears, some light some dark..

I read somewhere to prime with Zinsser Stain blocker.  

My questions are

1) Do I need to apply Zinsser to the entire room or can I just prime the really bad areas?

2) Do I need to sand after priming?

3) Over all, for the walls, is it ok to first coat with Dulux ceiling white instead of having 2 coats of the wall paint

4) Is Wash and Wear low sheen better or should I go for flat?

Thanks very much for any advice.

[EricL]

Hello @Cory12 

Thanks for sharing your question about your soot covered walls. The general steps to painting will be to sand your walls first and then wipe them down to remove all the sanding dust. Once the walls are clean, you can then apply the primer on your wall. When the primer cures you then put the topcoat on. I don't recommend doing a patch job on the wall where you only prime certain areas. It's best to start fresh and prime the entire wall so that you get a uniform finish.

In regards to the ceiling, I propose sanding it as well. The same process applies when painting your ceiling and that is to sand it down, clean it then prime and paint. 

Let me try and answer your questions.

• If you wish to use the Zinsser primer, please make sure to get the one that has the blocking feature. That would be the Zinsser 1L Bulls Eye 1-2-3 Undercoat Primer Sealer Stain Blocker.
   
• You need to sand before priming.
   
• For the walls use only wall paint and for the ceiling use only ceiling paint. Please do not mix and match them.
   
• The Dulux Wash and Wear low sheen finish is the commonly used finish for the walls. I don't recommend using flat or matt as it gets dirty quite quickly.

Here are some handy step-by-step guides:  

• How to paint a room
   
• How to prepare a wall for painting
   
• How to paint with a roller
   
• How to paint a ceiling

If you have any other questions we can help with, please let us know.

Eric