Applying plaster to a wall with a trowel needs a good wrist action and confidence

A step by step guide on how to plaster an internal wall. Expert DIY advice

Plastering is an essential process and procedure when carrying out internal home improvements or alterations to your property, but is it so easy that you can just read an article like this and then go and do it yourself?

Well not quite.

Plastering is a skilled trade in itself, so the likelihood of you reading this, printing it off, donning your overalls and plastering a room, if you have never done it before, is optimistic to say the least, but not impossible.

But for small areas of wall, or patch repairs, with a few attempts even you could get it right!

In fact like most home improvements, interior or exterior, practice and preparation can turn you into a DIY expert, after all, I had to start somewhere myself, in my case, at the tender age of 14 (in 1985) working for my Dad, so if I can do it, so can you!

We are going to show you, in 5 easy but comprehensively explained steps, how to plaster a wall.

One wise word of advice though: Prepare yourself in terms of mind and body.

No, you don’t need to Zen meditate but you do need to realise this is physical work and if you have never plastered a wall in your life, be warned this is hard physical work.

This is especially true as a certain aspect of urgency is involved in applying the plaster before it dries out and becomes useless.

Have a “warm up” before you start, and a good stretch of those muscles, and you will find you won’t tire so easily or make mistakes through having aching and over-worked limbs by holding that heavy “hawk” (your hand held mortar board) and laden with mortar or plaster.

Once you have done this to your own satisfaction, reward yourself with a nice sit down and cup of tea in true plasterer style, after all, you are going to need as much energy as you muster up, so a cup of tea beforehand really helps!

So without further ado, let’s get started shall we?

Everything you need to know about plastering an internal wall.

OK, the first thing you need to do, as we mentioned above, is to prepare what you need to do your plastering, and identify the area to plaster, which should be fairly easy to do.

Even a professional tradesmen plasterer has to prepare for plastering, even if that means mixing up the plaster and laying down dust sheets before they start work.

Working internally, as opposed to exterior rendering, is very different and requires a different approach altogether.

There are of course advantages in plastering or rendering internally as of course you don’t have to wrestle with the changeable weather, neither do you have to arrange and pay for scaffolding or a portable tower.

Saying that, when plastering an area with a high ceiling or a hallway, sometimes a trestle or some other safe working platform should be used instead of stretching to reach, as when you plaster, you need to express yourself with bold, confident and sweeping hand movements and not be restricted by hanging off a ladder or something.

You must think SAFETY when doing work such as this. We don’t want to hear you ended up in hospital after taking our advice.

Get yourself prepared and ready

Anyway, the first thing you should do is to move all furniture, fixtures and fittings away from the wall to be plastered, and cover everything else with dust sheets, OK?

Then get all your tools together, ready to work.

They should include:

  • Plastering trowel (Don’t buy a cheap one, it wont last, and the handle will give you callouses or blisters)
  • A Hawk. (This is the flat board with a short “pole” to grip with and your plaster will be laid on here and then collected with the trowel, but unless you are Geoff Capes or Hulk Hogan, don’t overload it)
  • Paddle accessory and power drill. (This makes the mixing of the plaster much easier and quicker. Remember plaster will start to set in the bucket or on the board if you take too long.)
  • A bucket. Once again, don’t buy the cheapest
  • Angle beading. These can make corners much easier and neater.
  • A much bigger mixing bucket. For …..er….. mixing!
  • A good quality paintbrush.
  • Multi-finish plaster
  • Scrim tape for any board joints
  • A lump hammer and cold chisel (for taking the old plaster off if applicable)
  • Dust sheets to contain the mess.
  • Water, for mixing into the plaster, amongst other things
  • And some cleaning stuff like rags, dustpan and brush etc.
  • And of course wear some old clothes. Your suit and tie is not suitable for this work.

 

Next, prepare the area around where you want to re-plaster.

Remember you will be removing the old plaster from the wall, so make sure you have a system to dispose of the old plaster, such as sacks, a wheelbarrow or maybe a skip or dumpster outside.

Fix your angle beads to the edges of the wall, and that includes around fireplaces or nooks.

It is good practice to constantly wet the wall when hacking off old plaster, or you will find the room quickly fills with dust, making the work area uncomfortable and potentially dangerous.

You need to protect the floor too, and if it is carpet, it is usually best to lift the carpet and roll it back to avoid damage and stains.

You also need to remove skirting boards, dado rails, picture rails, in fact anything that is nailed or stuck to the wall, and that may include your radiator, so you need to shut the heating system off and drain it before you do that.

When messing around with things like removing heaters it may be best to consult a qualified heating engineer as to the best way to do this.

Don’t mess around with gas installations and if unsure about draining the heating system (remember it will need to be refilled and the pipes bled of air once the wall is plastered, seek advice for a gas professional.)

Remove all the old plaster from the wall and dispose of it. You may need to take that to your local rubbish tip, do NOT chuck old plater into your domestic waste bin.

Check the condition of the wall and make any repairs if needed.

Now let’s get some plaster on the walls.

Now you have your bare wall, it is time to start plastering it.

1. Mix your plaster

Always mix the plaster based on what the bag says.

You have got to always add plaster to the water and not the other way around, so make sure you measure well AND use a clean bucket each time you make a mix.

You have then got to mix up the plaster itself into that water very thoroughly, it takes hard work and patience to get the mix just right, so no lumps and nice creamy consistency.

You will find the very best way to mix the plaster would be to use your Paddle accessory and power drill, mentioned earlier in theThen get all your tools together, ready to work...” section we saw above.

TIME is also of the essence here, especially if you are DIY’ing in the summer time, and this is because quite simply, as soon as you make that mix, it is going to start drying, more so when it is out of the bucket and on your hawk, or the wall itself, so work quickly and only mix small amounts at a time.

“When newly mixed plaster starts drying out, it is ruined and you have to throw it away. Even adding water to try and hydrate it, will make matters worse and you will waste your time as the mortar or plaster will have lost its strength and workability.”

2. Applying the first plaster coat

In most cases, 2 coats of internal render or plaster are needed to plaster a wall and achieve a good, smooth and level finish, however you can drastically minify this if you are plastering on brand new gyproc plaster board walls or drywall sheets.

You need to scrape a trowel full of your mortar or plaster mix, out of the bucket or off a board you may have used to mix it up, and then plop it onto your hawk.

Then collect half that amount from your hawk, onto your trowel, using a slice (into the middle) and then a flick of the wrist to scoop it up, with the mortar mixture of course facing upwards.

If the mix is too wet, at this stage, it will slide off the trowel, so pay attention when mixing!

Applying plaster to a wall with a trowel needs a good wrist action and confidence
Applying plaster to a wall with a trowel needs a good wrist action and confidence

Then starting at the bottom of the wall, use nice and smooth strokes with the trowel and press the mortar onto the wall and try and distribute the plaster on the trowel evenly over a certain area.

Use your whole body and bend your legs when doing this.

Always keep that trowel at a slight angle when laying up (applying) plaster or all of a sudden, your trowel will “stick” in one spot on the wall, by the suction effect that your wall has when the plaster is drying.

The very suction effect (or capillary retraction to be a smarty pants) is why your newly spread bit of plaster is now, we hope, sticking to the wall, and not sliding off again.

You should “rinse and repeat” as the saying goes and apply this to the whole wall, or at least if there are alcoves, apply each section at a time before going around the corner.

And then you are done with the first coat, so allow it to dry, and open the windows in the room for added ventilation.

If the weather is very hot, and so is the room you are in, this could cause the plaster to crack as it is shrinking and drying far too much so the expert “spreads” would use a couple of fans in the room to make sure the plastered wall does not dry too quickly.

You can also gently flick water onto the wall to slow down the drying and curing process if needed.

It is good practice at this point to give all your tools and buckets a good clean, and tidy up the work area too, and remove any rubble, waste, dust and dirt before continuing.

3. Applying the second and final skim coat of plaster

Now you are ready to apply the second coat, mix your plaster and get yourself ready, as indicated in the steps above and apply your second coat of plaster.

The difference with the top coat of plaster is the fact that you need to try much harder to achieve a good quality, smooth and flat finish because this is the surface that the new paint will go on, so any bits missed, lumps and so on, will stick out like sore thumb once paint is applied.

So first thing, get rid of any lumps and fill in any missing bits, then clean around the edges of your wall with a wet paint brush, especially where your new wall abuts onto the older wall next to it. Satisfy yourself that the top coat of plaster you just applied is good enough.

Then, and remember the clock is ticking here, it is time to smooth out that surface to create your new wall.

You have to wait until your plaster has hardened slightly but is still pliable and workable and then introduce your trowel to the wall again, at an angle, and work that surface, smoothing as you, with long sweeping movements.

You must use all your body to do this and you want to try and achieve the movement where your trowel goes from the bottom of the wall to the top in ONE sweeping flourish.

4. The drying and “polishing” of your newly plastered wall

Now is the time to have your second cup of tea whilst you wait for the plaster to dry out, which usually takes about three quarter of an hour.

We now start the “polishing” process.

Take your trusty trowel and wet the fact of it, and then flick water onto the wall using your paintbrush which will provide lubrication for your trowel.

This is the final smooth over that the wall needs for a really good finish, but be gentle with the wall as it is delicate still, but your actions in running the trowel over the wall will fill in any remaining tiny holes and voids.

Then clean up your tools and the work area, including your trowels and mixing boards and remember to close up your bags of un-used plaster, but bear in mind once opened they will only keep for a couple of weeks so if you have no more plastering planned, chuck them away.

Well done, you’ve done it. But you are not quite finished as you can’t just leave the wall like that!

5. You have plastered a wall! Now to paint it.

man painting exterior brick walls

Now you have your new wall, you need to paint it, so once you are sure it is dry, you need to “mist” over the wall which means thinning down some emulsion and painting over it, then leaving to dry, to give the proper paint a good key to adhere to and also to stop anything from the plaster bleeding through your new paint.

Some DIY stores do sell a plaster sealer but only DIY people ever buy it as the tried and traditional method is the misting process, plus its cheaper!

The thin paint coat may also highlight imperfections on your wall, which can be removed with light use of sandpaper and filler, as needed.

Then leave a day or two for the wall to fully dry, depending on the time of year and the ambient temperature, and then apply two coats of a good quality emulsion paint.

And there we are: One newly plastered freshly painted wall which you did yourself!

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