Problems may include walls that are unsuitable for paint finish, and linings that have cracked due to building movement.
Internal linings may have been affected by building movement (causing cracks at the stopped sheet joints) or the general deterioration or damage that occurs over time. Occasionally a leak from the outside or from a pipe may result in damage.
As wallpaper was the common finish, the original surface of the walls may not be suitable for a paint finish - a full skim coat of gypsum plaster may need to be applied first. Plasterboard joints may not have been reinforced, and it is common for the vertical sheet joints to crack. Typically this was hidden under the wallpaper, but where a paint finish is used, cracks will be visible (unless the joint is completely raked out and re-stopped with new compound and joint reinforcing tape).
Where a paint finish is desired, applying a lining paper or a plain embossed paper to the lining materials, after filling cracks and imperfections, may assist in providing a surface that is better for a paint finish.
Damage to ceilings is not common, but cracking may have occurred if there has been building movement or there has been a roof leak or a leaking pipe in the ceiling. If the ceiling is secure and any leak repaired, the only repair required to the ceiling will be cosmetic.
A plasterboard ceiling may be preferred to replace a softboard ceiling, in which case the softboard may be left in place and covered with plasterboard to retain the insulating and sound absorption benefits of the softboard.
If an original 1970s textured finish is still in place on the ceiling, be aware that it may contain asbestos fibres. Any such finishes remaining are likely to be nearing the end of their life (they become crumbly) and are likely to need removal by a specialist contractor.