Brush marks on skirting boards are one of the most common frustrations for DIY painters, but they're almost always preventable. The culprits are usually a combination of the wrong brush, paint that's too thick, rushing between coats, or skipping proper preparation. Follow the steps below and you'll get a finish that looks like a professional painter did it.
Why Brush Marks Happen
Understanding the cause makes the fix much easier. Brush marks form when:
- Paint is too thick and doesn't level out before it dries
- The brush is low quality and leaves heavy bristle lines
- You're overworking the paint — going back over paint that has already started to tack
- The surface wasn't properly sanded between coats
- The room is too warm or draughty, causing the paint to skin over before it can self-level
Step 1 — Prepare the Surface Properly
Good prep is the single biggest factor in a smooth result.
- Clean the skirting boards thoroughly — remove dust, grease, and any wax with a sugar soap solution and a damp cloth. Rinse and allow to dry completely.
- Sand back existing paint with 120–180 grit sandpaper, working with the grain of any timber. If there are existing brush marks or drips, sand these flat first.
- Fill any gaps or dents with a flexible acrylic filler (available at Bunnings or Mitre 10), allow to cure, then sand smooth.
- Wipe down with a tack cloth or lightly dampened cloth to remove all sanding dust before painting.
Step 2 — Choose the Right Paint and Brush
Paint
For skirting boards, use a water-based acrylic enamel or semi-gloss/gloss trim paint. Modern water-based enamels have excellent self-levelling properties and are much easier to work with than traditional oil-based paints. Good options available in NZ include:
Always check the manufacturer's data sheet for recommended application conditions — most water-based paints should be applied between 10°C and 35°C with good ventilation but no direct draughts.
Brush
Invest in a quality synthetic bristle brush — a 50 mm or 63 mm angled sash brush works well for most skirting boards. Cheap brushes are the number one cause of brush marks. Look for brushes from reputable brands at PlaceMakers, Bunnings, or Mitre 10.
Step 3 — Thin the Paint if Needed
If your paint feels thick or is dragging on the brush, add a small amount of water (for water-based paints) — typically no more than 5–10% by volume. Stir thoroughly. Over-thinning will reduce coverage and sheen, so add water gradually. Check the tin label or the manufacturer's website for guidance on thinning ratios.
Step 4 — Apply with the Right Technique
This is where most DIYers go wrong. Follow this method:
- Load the brush correctly — dip about one-third of the bristle length into the paint, then tap (don't wipe) gently on the inside of the tin to remove excess.
- Apply along the length of the skirting board in long, smooth strokes, working in one direction.
- Lay off the paint — finish each section with a single, very light stroke from one end to the other, barely touching the surface. This is the key step that removes brush marks.
- Work in manageable sections of around 600–900 mm at a time so the paint doesn't start drying before you lay off.
- Don't go back over paint that has started to tack — this is what causes drag marks and ridges.
Step 5 — Sand Between Coats
Once the first coat is fully dry (check the tin for recoat times — typically 2–4 hours for water-based), lightly sand with 220 grit sandpaper. This knocks back any minor nibs or brush marks. Wipe clean, then apply your second coat using the same technique. Most skirting boards benefit from two finish coats over a primer.
Step 6 — Control Your Environment
- Paint in mild, still conditions — avoid painting on very hot days or in direct sunlight
- Keep windows open enough for ventilation but avoid strong draughts that speed up drying
- In winter, ensure the room is at least 10°C — cold slows drying and can cause paint to sag
Common Mistakes to Avoid
| Mistake | What to do instead |
|---|---|
| Using a cheap brush | Buy a quality synthetic sash brush |
| Skipping sanding between coats | Always sand lightly with 220 grit |
| Painting in hot, windy conditions | Choose a mild, still day |
| Overloading the brush | Load lightly and lay off with a feather stroke |
| Rushing recoat times | Follow the manufacturer's recoat window |
When to Call a Professional
If your skirting boards have significant damage, are part of a heritage home with lead paint (common in NZ homes built before 1980), or you're simply not getting the result you want, it's worth calling in a qualified painter. Lead paint is a serious health hazard — WorkSafe NZ has guidance on safe handling. A professional painter will have the tools, experience, and products to deliver a flawless finish efficiently. You can find qualified local painters on tradedirectory.co.nz.
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