Paint defects – Identification, cause and solution – Interiors

Knot staining

Cause: Failure to use a knotting solution (usually shellac based) before painting

Solution: Rub down the area and apply a shellac based knotting solution or stain blocker and re paint.


Cause: Timber has ‘checked’ allowing moisture to penetrate and cause the paint to lift.

Solution: Scrape back to a sound surface and repaint.

Sagging / Running / Curtaining

Cause: Paint has been applied too thickly and additional coats have been applied before the previous was fully cured.

Solution: Completely remove the paint and repaint.


Cause: Generally cissing is caused by the application of paint to a surface which has not been properly prepared. The surface will likely be contaminated with grease, oil or polish.

Solution: To resolve cissing, the surface should be left to dry, thoroughly rubbed down and cleaned before applying further coats of paint.

Crowsfooting / Checking

Cause: Underlying paint has a different tensile strength to the top coat. Meaning expansion and contraction varies and causes cracking.

Solution: The use of a more flexible top coat will be necessary.


Cause: An emulsion paint has been applied to an underbound material.

Solution: Remove back to bare plaster, use a stabilising primer to prepare the new surface followed by reapplying the paint.

Mould growth

Cause: Organic growth on interior surfaces is usually caused when condensation and damp penetrates into the plaster.

Solution: Wash with bleach and water, apply a biocide or fungicide solution to kill any remaining organic growth and repaint.


Cause: An alkyd based paint has been applied to an alkali surface without the use of a suitable primer.

Solution: Remove the soft film and clean thoroughly with white spirit. Once dry, use an appropriate primer and reapply the paint.


Cause: Softening of a previously applied paint, usually due to the fact the subsequent coat was applied before the former was fully cured.

Solution: Sometimes you can rub down the surface to make it smooth again and reapply paint. Although in extreme cases you may need to completely remove the entire coating.

Like this sort of stuff?

Join my mailing list for FREE and get regular tips to improve your marketing

Success! You're on the list.
%d bloggers like this: