markings on the wall

[TheMitchells]

I was invited into one of our neighbours house today which is always interesting to see how the houses differ, even though all built the same time (Victorian terrace).  She pointed out a problem that she has with her lounge walls.  When she moved in, the walls were papered and painted orange.  As it wasnt her favourite colour, her son painted the walls a light grey which looks nice.  However, all over the walls there are slightly darker marks.  It looks as if there was areas of oil which is now coming through the lighter paint.  Its all over and looks rather unpleasant.

Any ideas what caused it and what she should do?  She's worried that the marks will come though again if she paints it again. 

She didnt want to strip the wall as they are in poor condition and she is worried that the lath and plaster will come off, causing lots more work.   

[Barney12]

By any chance were the walls painted Orange as that's the best colour to disguise nicotine/tar stains from heavy smoking? 

What you're describing sounds like the nicotine/tar seeping through.

The only real fix is to paint with a stain block, the Zinsser products are excellent. 

[Declan52]

I used them zinseer paints before to hide mould stains and they definitely work.