strip the paper off, clean the wall with mix of bicarb in warm water let it dry then fill dents and cracks sand down then size with fungicide paste thin mix and two coats allow each to dry then cross line with 1000 grade lining paper along the wall not down like wall paper butt the joints, any gaps fill with filler and gently sand over when dry. Re-paint and you won't see the joints if you do it properly.
bob, February 2011
