How to Plaster a Wall

How to Plaster a Wall

Plastering a wall is a job often left to the experts, but if you’re a dab hand at DIY and have a home project that you want to complete, you might be considering doing the job yourself. The good news is, it’s fairly easy to do once you know how. 

To help you ensure you get the best possible finish, here at Build & Plumb, we’ve created this step-by-step guide on how to plaster a wall from start to finish.

You will need:

1. Prep your walls and floor

Before you start plastering, you’ll need to first ensure your floors are protected with a dust sheet, and this’ll also make it easier to clean up when you’re finished. It’s also important to ensure that your walls are clear of dust and debris. Clean and wipe down your walls to make sure there’s no remaining plaster, dust or wallpaper in the way. If your walls have any obvious holes or cracks, cover them with plastering tape. If you’re plastering new plasterboard, apply tape over the joints.

2. Apply PVA glue

Next, apply a layer of PVA glue to your wall. This is necessary for bonding the plaster to the wall and will help ensure it’s all even. You’ll need to dilute your PVA first; a mix of one parts glue to four parts water is standard, but check the back to check for specific instructions. Simply roll this onto your wall using a roller. Wait for the glue to feel a bit sticky, then apply your plaster.

3. Mix the plaster

While you’re waiting for your PVA to feel tacky, mix your plaster. To do this, fill a bucket with tap water and gradually add your plaster in and whisk it until it has a thick consistency with no lumps. If you’re only pasting a small amount, you can manually mix your plaster, but if you’re covering a large area, we’d recommend using a power mixer. 

Tip: Be sure to clean your mixer before the plaster sets! 

4. Apply the plaster

Once your plaster is the right consistency, you’re ready to apply it to your wall. To do this, use a trowel to add a fairly small amount to your hawk board. Then, starting at the bottom left corner of your wall, use your plasters float (or a plasterers trowel) to apply it to the wall in an upwards direction. At the end of each stroke, flatten the float to make sure the plaster is smoothed down. Keep going until the plaster is evenly spread and the wall is covered.

5. Smooth out bumps

At this stage, wait for your wall to dry for approximately 20 minutes. Then check for any lumps and smooth out your plaster by running over it with your trowel. If the corners and the top and bottom of your wall need smoothing out, use a wet brush to even these out.

How to Plaster a Wall

6. Apply a second layer

Next, apply your second layer of plaster. Some plasterers use a devilling float to scratch the wall in order to create a better surface for the next layer to adhere to. However, if you want to skip this step, you can – just make sure the wall is still wet before applying your next layer.

Apply your next coat just as you did the first, but be sure to make it thinner this time (approx. 2mm) by diluting it more. Once finished, leave to dry for 20 minutes.

7. Finish up

Now all that’s left to do is to make sure everything is smoothed out properly. Using a spray bottle, spritz the wall – particularly around the corner and edges again. Use your brush again on these tricky areas and a clean float to smooth any lumps. Then, leave your plaster to dry completely. After it’s dry, you might find you need to use a bit of sandpaper to buff off any remaining lumps.

Once you’ve ensured a smooth and even surface, your plaster is ready for painting or plastering! However, you must wait until it’s completely dry.

How long does plaster take to dry?

If you’ve painted onto plasterboard, it’ll take plaster approximately 2-3 days to completely dry. If you’ve used backing plaster, it’ll take around 4-6 days. 

It’s important to wait about a week before painting or wallpapering onto your plaster though, to ensure it’s completely dry. To speed up the drying process, ensure your room is well ventilated, but turn off the radiators, as this can cause the plaster to crack.

A good way to tell if it’s completely dry is by checking for any dark patches. Your plaster should look light and all the same colour – any discolouration at all and you’ll know it isn’t dry. 

Now you know how to plaster a wall, you can start your DIY project with confidence. Follow these steps and your walls should be finished to a professional standard. 

Before you start, you may want to practice your technique on a spare sheet of plasterboard first. Refer back to these steps if you need a refresher at any stage, and remember to follow the manufacturers’ instructions on all your products, as some may differ. Find the high-quality plastering products you need to get started in our range of plastering tools and more from our full plastering range.

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