In Quick Guides

Quick Guide To Plastering

Need to know how much plastering costs, whether you can plaster yourself, the difference between types of plaster or how to find a great plasterer? Read on for your quick guide – plus lots of references to find more info – on everything to get your walls smooth and beautiful.

What is plastering?

Plastering is the process of applying a layer of mortar over an exposed surface of a building, such as brick or breeze block walls. It protects the surface and provides a smooth layer on which to paint or wallpaper.

What’s the difference between plastering and skimming?

Generally, ‘plastering’ is applied to a non-plaster surface (such as brickwork), whereas skimming is adding a very thin layer of fresh plaster onto existing plaster, often because that existing plaster is cracked or damaged. As such, skimming is a sub-set of plastering.

That said, when speaking with tradespeople about plastering or skimming, ‘plastering’ will be understood as a general term that covers skimming as well.

Do I need to re-plaster?

How to know whether you should re-plaster your walls will be based on a series of factors:

  • If you’ve recently moved to a new house, you should consult your home buyer’s survey for recommendations of re-plastering
  • If you have walls or ceilings that are badly stained from historic and now rectified leaks or fire damage
  • Uneven existing plasterwork can be rectified with a skim of smooth plaster
  • Small cracks that are not related to any structural damage can be covered with fresh plaster

Note: re-plastering is not a solution for structural damage to walls, or to cracks caused by subsidence. In these instances, re-plastering would literally just paint over the cracks!

You may not need to re-plaster if…

  • Stains are more minor and could be covered with a ‘problem wall’ paint
  • Cracks are so fine (hairline cracks) that ‘problem wall’ paint would rectify
  • If cracks are small in number or isolated, you may be able to repair these with filler rather than fresh plaster

For this sort of minor damage, you may be able to avoid the expense of re-plastering or skimming by opting for a hybrid paint product. Polycell have a great range of paints for problematic walls to cover stains and hairline cracks – use these as a primer to achieve a smooth surface, then finish with your chosen paint colour.

Can I do plastering myself?

We’re pretty DIY-positive here at This 1870 House, but we don’t recommend doing plastering yourself. A small patch to cover damage or a hardly-seen area (such as the inside of fitted storage) might be fine, but plastering is a high-skill activity.

If you have period features or unusual corners, you absolutely should not attempt this yourself.

Plastering also has a lot of materials and equipment required, so you may not save an awful lot of money once you’ve laid out for these. If at all possible, employ a professional to get the professional finish you’re after.

When is plasterboard used?

Plasterboard is a panel of gypsum plaster. It’s also know as ‘drywall’. It is a popular alternative to traditional plaster because it’s pre-made and cut be cut to size. It effectively places an entirely new smooth surface in front of the wall or ceiling.

It isn’t an option for skimming jobs, but is often used for new constructions. It is also used for over-boarding ceilings (more on that later).

What does plastering involve?

In brief, the plastering process follows these steps:

  1. Walls are prepared by cleaning and removing paper or, in some cases, paint (more on this later)
  2. A coat of PVA is applied to walls to create a tacky surface
  3. A first layer of plaster is applied. For skimming jobs, this may be the only layer in which case it is finished smoothly
  4. For more substantial jobs, additional coats are applied to achieve the required thickness. The final coat has a smooth finish.

Find out more about the details of the plastering process here.

Plastering ceilings

Ceilings can be plastered over to obscure stains, minor damage and hairline cracks. It is also common as a means to obscure a textured ceiling. Textured wallpaper cannot be plastered directly, so this would need to be removed to reveal the original plaster(board), or an over-boarding technique would be required.

Over-boarding is the technique of attaching plasterboards to an existing surface and lightly skimming over for a flat finish. For ceilings, the boards are attached to ceiling joists.

Some plasterers will apply traditional plaster to an Artex-style textured ceiling using the PVA base to ensure adhesion. However, it’s important to note that Artext and other textured ceiling finishes may not be strong enough to ‘hold up’ the weight of the new plaster. For this reason, some plasterers will insist on over-boarding in these instances too.

How much does plastering cost?

Take a look at Household Quotes for a really comprehensive list of cost estimations for plastering.

  • A medium sized room (walls only) will cost around £500 and take 1-2 days
  • A medium ceiling should cost around £300 to skim (more to over-board) and take 1 day
  • A large room or a room with complex period features could cost up to £1,000 and take up to a week

When obtaining a quote, always check that labour, materials and clean-up are included – this may include disposing of spare plasterboard at a tip.

Remember that tradespeople have to pay to dispose of materials at a tip, so you may be able to bring a quote down by offering to do this yourself.

For This 1870 House, our plastering project comprised 2 x medium sized rooms, 1 x Victorian bay window construction, 2 x medium ceilings over-boarded, 1 x medium ceiling skim. The total was £2,800 and the project took 5 working days.

How to prepare your house for plastering

You cannot plaster over lining paper or wallpaper. If you wish to have rooms with this plastered or skimmed, the paper must be thoroughly removed first. Even scraps of paper can compromise the finish as the plaster will not properly bond to it.

You can plaster over paint, providing the paint is in reasonable condition. Peeling, cracked, flaking or otherwise damaged paint will need to be removed first.

Remember: in a period property, always rule out lead paint before you remove or disturb it.

For both of these, you should discuss with your tradesperson whether they will include these services, or if you will need to a) prepare walls yourself or b) find another professional to do this first.

You should also consider mess! Plastering creates a huge volume of dust that settles everywhere that isn’t shut off. Ideally, clear all furniture and possessions out of the space that will be plastered. If that isn’t possible, thoroughly dust-sheet and prepare to deep clean afterwards.

Plaster or lining paper?

If you have uneven or lightly damaged walls, you might be weighing up re-plastering versus applying lining paper. Lining paper is a sturdy, high GSM plain paper that creates a smooth surface ready for painting. It is applied like wallpaper in large sheets, using pre-mixed paste.

The pros of lining paper are…

  • Substantial saving versus plastering
  • Easier to do yourself (experience applying wallpaper should be enough to apply your own lining paper)
  • Quicker than plaster
  • Less time to wait before you can paint
  • Works well to disguise stains or minor surface imperfections

The cons of lining paper are…

  • Finish is inferior to properly applied paster
  • Doesn’t always hide discrepancies in shape of walls, e.g. will not correct wonky corners
  • Joins between sheets are sometimes visible
  • If not applied carefully, can result in bubbles or creases (much like regular wallpaper)

Lining paper should not be applied over other layers of wallpaper as this will also compromise the finish, and applying paste to existing paper can cause wrinkling.

How long does plaster take to dry?

Plasterboard and skim usually takes 2-3 days to dry. Thicker plaster will take longer.

To encourage plaster to dry more quickly, keep the house warm – this is especially important in period properties, homes prone to damp or uninhabited properties.

Plaster must be completely dry before painting. You should wait at least a week to ensure plaster is fully dry, but be aware that thicker plaster could take up to a month. You can tell plaster is dry by an even, paler colour compared to when it was applied.

At this point, you can paint or apply wallpaper. You shouldn’t ever need lining paper on fresh plaster as the finish should be smooth.

When painting fresh plaster, your should use a mist coat – this is a watered down first coat of paint. This is because fresh plaster is extremely porous and any moisture will be quickly absorbed into the wall. You want this to happen with your mist coat instead of a coat of your (more expensive) finish paint because the latter could impact the finish.

To make a mist coat, use 2 parts of a cheap white emulsion with 1 part water. Mix thoroughly then roller onto your walls and/or ceiling.

After this coat, you can apply your chosen finish paint as usual. Then step back and admire your newly smooth, crisp walls!

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