How To Paint Interior Walls Like A Professional

With 72% of professional decorators in the UK considering themselves as likely to increase their prices this year along with rising petrol, energy and food bills, the number of people looking to redecorate their own homes in an effort to save money is almost guaranteed to rise.

Whilst painting your interior walls might seem like one of the easiest tasks on your to-do list, it’s actually a substrate where lots of mistakes are made by DIYers. These mistakes range from framing effects to cracked emulsion. Fortunately, we’ve put together the ultimate guide on how to paint a wall yourself and get professional results – even if you’re a beginner.

What Do I Need To Paint A Wall?

The first stage of any decorating project is planning ahead. With that in mind, you need to make sure you have all the tools to hand and for painting interior walls we’d suggest having the following at your disposal:

Interior wall paint*25mm cutting in brush
FillerRoller & tray
Masking tape150 grit sandpaper
Dust sheetsScraper

*We’d recommend measuring the walls that are to be painted so you know how much paint you will need. For example, if the area to be covered is 12m² and you assume that you will need 2 or 3 coats, you will need at least 3L of paint such as Johnston’s Matt Emulsion (which covers 12m²/L).

Furthermore, we’d highly encourage you to choose a matt emulsion rather than silk, especially if you’re a beginner. Matt emulsion refracts light and so any mistakes you do make won’t be highlighted.

Of course, if you really want a professional finish then use a trade paint.

How To Paint A Wall

Now you’ve got all your tools ready, let’s move on to the next step in the process.

Step 1: Prepare the room

Before you even pop the lid off your paint tin, you’ll need to make sure your flooring and furniture are fully protected from spills, drips and splashes.

Tips to protect the room:

  • Place dust sheets down on the floor and secure them with tape. Standard dust sheets will usually suffice but if you want extra peace of mind, buy high-quality cotton twill dust sheets. If painting the walls next to a staircase, you can buy specifically designed narrow-width dust sheets.
  • Remove any portable items from the area. If you can’t remove larger pieces of furniture such as sofas from the room, move them to the middle of the room instead.
  • If painting kitchen walls, make sure that electric or gas hobs are turned off to prevent any fire hazards.
  • Remove curtains, blinds, nets and curtain rails and store them in a different room.
  • Use masking tape to protect linear work such as skirting boards, door frames and windowsills. Bear in mind that masking tape becomes more adhesive the longer it’s left on. If left on for too long, you could damage surfaces when removing it.
  • If you’re going to be in and out of the work area, think about purchasing some disposable shoe covers. This will ensure you don’t inadvertently drag paint throughout your home.
  • Make sure the area you’ll be preparing and painting is adequately ventilated.

Step 2: Surface preparation

Once the room is fully protected you can move on to step 2 which is surface preparation. This is the most important step in the whole process of painting a wall and is what separates the DIYers from the professionals.

Making good any imperfections

Carefully examine the walls you want to paint. If you notice any imperfections such as holes or flaking paint, you will need to make good the surface. For holes, you can use a filler that can be abraded once fully dry.

Imperfections that were filled and sanded.

Any flaking paint can be scraped away with a scraping tool but if you notice that the surface is powdery underneath the defective paint, you’ll need to add a coating of stabilising solution.

Once the stabilising solution has dried you can dry sand the entire surface using small, circular movements. Remember to use a dust mask, goggles and clothing that covers your skin when sanding the surface down. Dust from sanding can be irritating for your eyes, lungs and skin.


Degreasing is a stage that many beginner DIYers either forget about or simply don’t know about. Our internal walls will have some sort of grease on them – whether that’s from cooking in the kitchen, overspray from furniture polish in the living room or aerosols in the bedroom.

It’s important to remove these remnants of grease as it can hamper the adhesion of your paint system.

To degrease your walls, simply mix some sugar soap and warm water and apply using a cheap washing down brush.

Kitchen paint is especially in need of degreasing!

Remember to clean the walls with clean water after degreasing and make sure the surface is thoroughly dry before applying coatings.

Priming/Stain blocking

Whilst this step isn’t strictly necessary if your walls are in good condition, those who have walls that have been affected by nicotine stains, water damage, burns or ink stains will definitely want to use a stain blocker before painting.

Water-borne stain blockers are a primer that conceals any stains but more importantly ensures that those stains don’t seep through your paint coatings.

Step 3: Mentally divide the wall into sections

One of the most important aspects of getting a professional finish on your walls is to ensure you’re working with a wet paint edge. If the edge of the paint is allowed to dry and you overlap fresh paint on the dried paint, you’re going to lift that dried paint off the surface.

This will be very visible once fully dried and will mean that you’ll need to paint the entire surface again to fix the issue.

This is what happens when you fail to work with a wet edge.

With that in mind, we’ve created a diagram below that gives you the perfect painting sequence to maintain a wet edge (paint from sections 1 – 6). The sequence remains the same even if you have an extra pair of hands helping you. If there are 2 of you painting, follow this sequence with 1 cutting in and 1 rolling.

Step 4: Apply masking tape

Applying masking tape now serves two purposes; firstly, it will protect your skirting boards, door frames, ceilings, light switches etc from any paint and secondly, it will give you those razor-sharp professional lines, especially if you’re painting your walls a different colour to the ceiling or are painting a feature wall.

Whilst professionals don’t typically use masking tape to cut in around edges, it’s advisable for beginners as cutting in freehand without masking tape is a skill that takes time to develop.

Even beginners can achieve straight lines if using masking tape.

Step 5: Applying the first coat

Now on to the fun part – applying your paint system. With the sequence for painting your wall in mind, start cutting in around the edges using a 25mm brush and then fill in the rest with a roller. When rolling, use an ‘M’ motion, overlapping each roll line as you do.

You can paint the entirety of your walls using a synthetic flat wall brush that is 150mm if you want but bear in mind that it will take a long time and leaves you open to brush marks on the surface. If you are going to just use a brush, then you will need to lay off using the ‘cross-hatching’ method as this will minimise the appearance of brush marks.

Step 6: Allow the paint to dry

It’s imperative that you allow the first coat to not only become touch dry, but to become hard dry too before applying the second coat. The drying time of emulsions vary but typically you will need to wait at least 4 hours before applying the second coat.

If you don’t allow the first coat to become hard dry, your roller will pick up the coat which will create an undesirable visual effect on your walls.

Step 7: Apply the second coat

Once you’ve waited the correct amount of time, you can go ahead and apply your second coat. At this stage, you can simply repeat the process of step 5.

If painting a light colour over a darker colour, you may need to apply further coatings.

Step 8: Remove the masking tape

Depending on how steady your hand was during the cutting in, you might’ve got some paint on the masking tape. It’s important to remove the tape before this paint becomes hard dry. If the paint is hard dry when you’re removing the masking tape, there’s a chance that you could pull away some of the paint work with the tape.

With that in mind, remove the masking tape whilst the paint is still somewhat tacky and do so in a downwards motion as this will help you achieve those professional-looking straight edges.

Step 9: Pack up and wash your tools

By now you should have freshly painted walls that professional decorators would’ve charged you hundreds of pounds for. But of course, the downside of painting yourself is that you’ll also need to clean up yourself too!

As wall paint is water-borne, you can wash your tools using clean water. Before washing your brushes you can use the paint tin to remove any excess paint then proceed to rinse them under running cold water.

The process for cleaning rollers is much the same as for brushes.