If you’re planning a paint job and wondering whether you really need primer, the answer is… probably. Primer might not be the most exciting part of painting, but it’s often the difference between a quick touch-up and a lasting finish.
This guide covers the basics: what paint primer is, how to choose the best paint primer for your project, and how to work out how much primer do I need, without the guesswork.
What Is Paint Primer?
Primer is the base coat that helps paint stick properly. It seals the surface, evens texture, and gives your topcoat something solid to bond to. Without it, your paint might soak in unevenly, peel too soon, or require extra coats to get the right colour.
Primer is especially useful when:
- You’re painting raw or porous surfaces (like fresh plaster or brick)
- You’re covering up stains or strong colours
- You’re switching from oil-based to water-based paint
- The surface is patchy or has been repaired
If you’ve had to fix cracked paint or strip old paint off glass, a good primer helps reset the surface so your paint goes on clean and even.
Choosing the Best Paint Primer
Not all primers are the same. Here’s how to match the primer to the job:
- New or bare surfaces (like timber, plaster, or brick) – Use an acrylic or masonry primer to seal and smooth out absorption.
- Water damage or smoke stains – A stain-blocking oil or shellac-based primer helps prevent marks from bleeding through.
- Wet or humid areas – Use a moisture-resistant primer along with the best paint for bathrooms to prevent mould and peeling.
- Shiny or slippery surfaces – You may need a specialty bonding primer for tiles, glass, or laminate.
Thinking of using a 2-in-1 paint and primer? These can work for light touch-ups or colour-on-colour changes, but if you’re working with tricky surfaces, we recommend using a separate primer for better results.
How Much Primer Do I Need?
Most water-based primers cover around 10 to 12 square metres per litre. That number can change depending on the texture and condition of your surface.
Here’s a quick way to estimate:
- Measure the total wall area (length × height)
- Subtract windows and doors
- Check the label on your primer for its coverage rate
- If the wall is rough or porous, you may need more than expected
For example, if you’re about to paint a brick wall, count on using more primer to soak into all the nooks and uneven surfaces. It’s always safer to have a bit extra than to run short halfway through.
How to Use Primer Properly
Once you’ve chosen the right primer, here’s how to apply it:
- Clean the surface – remove dust, dirt, or old flaking paint.
- Repair damage – patch holes and deal with peeling or cracks.
- Stir your primer well before using.
- Apply evenly with a roller or brush, pushing it into corners and textures.
- Wait for it to dry – check the tin for timing, and be sure to follow the wait between paint coats advice before painting over it.
If you’re not sure how long to wait or whether one coat is enough, reach out. We’re always happy to take a look or handle it for you.
Common Mistakes to Avoid
Skipping primer isn’t always a disaster, but it often leads to problems:
- Paint may peel or lift too soon
- Colours might look patchy or off-tone
- You could end up using more paint than planned
It also won’t fix surface issues like water stains or greasy marks. In those cases, primer is a must.
And if you’ve recently done any glass paint removal, or had to sand back problem areas, priming helps reset the surface so the paint behaves the way it should.
Need a Hand?
Primer might seem small, but it makes a big difference. Whether you’re refreshing a wall or painting a whole room, proper prep gives you a smooth finish that lasts.
If you’d rather not figure it out yourself, our home painting services cover everything from prep and priming to the final coat. We’ll match you with someone who shows up on time, brings the right tools, and knows how to get it done properly.
Book a quote today and get the job done right from the first coat.
