Skim a wall when the existing plaster is firmly stuck and the problem is cosmetic; replaster when it is loose, crumbling, badly cracked or damp-affected. MyJobQuote puts skimming a room at £455 to £758 and a full replaster at around £600 to £1,050. Skimming over failing plaster wastes the money.
Not every tired-looking wall needs to come off down to the brick. According to MyJobQuote’s cost guides, skimming a room typically costs £455 to £758, while a full replaster, removing the old plaster and starting again, runs closer to £600 to £1,050. Which one you actually need comes down to the condition of what is underneath, not just how the wall looks from a few feet away.
Skimming: the quick fix for sound plaster
Skimming applies a thin new finishing coat directly over existing plaster that is still firmly attached to the wall. It is the right call when the problem is cosmetic: minor cracks, small dents, an uneven or patchy finish from a previous poor paint job, or simply years of wear. A skilled plasterer can transform a tired looking room this way without the disruption of stripping walls back to the brick or blockwork underneath.
Replastering: for walls that are actually failing
A full replaster removes the existing plaster entirely and applies fresh base coats and a finishing skim from scratch. This is necessary, not optional, when:
- The plaster is loose or hollow-sounding when you tap it, even if it still looks fine on the surface
- It is badly cracked, particularly with cracks that reappear after being filled
- There is damp damage, since plaster affected by damp will keep failing until the underlying moisture problem is fixed and the wall is properly dried out and replastered
- Large sections are crumbling or coming away, rather than isolated small areas
Skimming over any of these problems is a false economy: the new finish will crack, bubble or fail within months, because the layer underneath was never sound to begin with.
Comparing the two
| Skimming | Full replaster | |
|---|---|---|
| Typical cost, average room | £455 to £758 | £600 to £1,050 |
| When it's right | Base plaster is sound, issue is cosmetic | Plaster is loose, cracked, damp-damaged or crumbling |
| Disruption | Lower, faster drying time | Higher, walls stripped back first |
Why getting this wrong costs more later
Paying for a quick skim over plaster that was actually failing means paying to redo the whole job again, properly, within a year or two, on top of what you already spent. A plasterer worth hiring will tell you honestly if a wall needs a full replaster rather than quoting the cheaper skim job to win the work, and will explain what they are seeing that leads them to that recommendation, not just assert it.
If a crack keeps coming back no matter how many times it is filled, or you suspect damp is involved, it is worth reading our separate guide on whether a crack in your wall is actually serious before deciding which of these two jobs you need.
Getting an honest assessment
Ask a plasterer to explain what they find when they check the wall, tapping for hollow spots and looking closely at any cracking, rather than just quoting from a glance across the room. We check independent reviews and genuine local trading history when we research our independent research, so a page for somewhere like Didcot or Chippenham is a fast way to find a plasterer who gives you a straight answer rather than the cheapest quote.
Frequently asked questions
How do I know if a wall needs skimming or replastering?
Skimming is usually enough if the existing plaster is firmly stuck to the wall and only has minor cracks, dents, or an uneven finish. Replastering is needed if the plaster is loose, crumbling, badly cracked, or affected by damp, since a smooth skim over a failing base coat will not hold.
How much does it cost to skim a room?
According to MyJobQuote, skimming a room typically costs £455 to £758 depending on size and wall condition, with a bedroom averaging £435 to £725 and a larger living room £645 to £1,075.
How much does it cost to fully replaster a room?
A medium sized room typically costs £300 to £450 to remove the old plaster, plus £300 to £600 to apply new plaster, putting a full replaster in the region of £600 to £1,050 overall according to MyJobQuote, more if there is significant damp or damage to address first.
Can I skim over old wallpaper or painted plaster?
Painted plaster can usually be skimmed over directly, provided the surface is sound and a plasterer preps it correctly first. Wallpaper should always be removed before skimming, since new plaster will not bond reliably to paper and can bubble or fail once dry.
Related guides
More problems and repairs guides · All plasterers guides
About the author
Stu Clark
Stu spent over 15 years in the trades, working as a plumber before running his own plumbing and bathroom renovation company with a team of eight. He founded Top5Trades to give homeowners the kind of shortlist and straight advice you would get from someone who has actually done the work. More about us →