Filling nail holes and cracks properly is one of the simplest ways to get a smoother, longer-lasting paint finish. If you skip this step, small blemishes often show through even after two coats, especially in good light or on freshly painted walls.
For Auckland homes, where humidity and older plasterboard can cause movement, a careful repair matters. Here’s how to do it properly before you pick up the paint brush.
Choose the right filler for the job
Start by looking at the size and type of damage. Tiny nail holes and shallow dents usually only need a lightweight interior filler. Small cracks may need a flexible filler or gap product that can move a little with the wall.
For hairline cracks, a standard filler can work if the crack is stable. If the crack keeps opening, or if it runs along a joint, it may need mesh tape or a more involved repair before painting.
Avoid using too much product. A thin, neat repair is easier to sand and will blend in better once painted.
- Tiny nail holes: lightweight filler
- Small moving cracks: flexible filler or gap product
- Wider or recurring cracks: may need tape and deeper repair
How to fill the holes and cracks
First, make sure the surface is clean, dry, and free from dust. Use a small scraper or putty knife to remove any loose paint or crumbly filler around the damage. If the hole has a rough edge, widen it very slightly so the filler can grip properly.
Press the filler firmly into the hole or crack with a filling knife, making sure there are no air pockets. For deeper holes, it is better to do two thin fills than one thick one. With cracks, push the filler across and slightly beyond the line of the crack so it bridges properly.
Let it dry fully according to the product instructions. Once dry, sand it smooth with fine-grit sandpaper until it feels level with the wall. Wipe away the dust before priming.
Prime, spot seal, and prepare for paint
Paint can sink into filler differently from the surrounding wall, which can leave a dull patch or flashing. That is why spot priming is important. Apply a suitable primer or sealer over the repaired area before topcoating, especially on larger patches or where the wall is porous.
If the wall has been damaged by water, always check the cause first. Painting over a damp stain or active crack will only hide the problem for a short time. In older Auckland homes, movement around windows, cornices, and joins is common, so take time to inspect those areas carefully.
Once the primer is dry, you can paint as normal. For the best finish, feather the paint out beyond the repair so it blends into the surrounding wall.
When to call Steve
If you are dealing with lots of nail holes, fine cracking, damaged plasterboard, or recurring movement cracks, it is worth getting advice before you paint. A poor repair can stand out even more once the new colour goes on.
Steve is a Kiwi and a trade-qualified painter, and he can assess whether a crack is just cosmetic or something that needs a proper repair. If you want a clean, professional result in your Auckland home or investment property, contact Steve early so the surface is prepared properly before painting begins.
Frequently Asked Questions
Do I need to prime after filling nail holes?
Yes, spot priming is usually a good idea. Filler absorbs paint differently from the wall, so primer helps create an even finish and prevents flashing.
Can I paint straight over small cracks?
It is better to fill them first. Even a small crack can show through the paint and may reopen if the wall is still moving.
What sandpaper should I use on filler?
Fine-grit sandpaper is usually best for a smooth finish. Sand gently so you do not scuff the surrounding wall or leave a dip around the repair.
Need a hand with your project?
Happy to tackle some of it yourself? Great — but for anything you’d rather leave to a professional, Steve Lunjevich is a Kiwi and a trade-qualified painter with 20+ years’ experience. Call or email for honest advice or a free, no-obligation quote.