This article will help you in identifying some common paint problems and their solutions. The key to avoiding any of these paint problems is always to use high quality coatings for the correct applications.
Poor Stain Resistance
What causes poor stain resistance?
Stains and dirt being absorbed by the coating, making cleaning difficult.
How do I fix it?
Incorrect type of coating used for areas prone to dirt contamination. Sheen and water based enamels are better suited for kitchens, playrooms, work areas and other surface areas which are likely to get soiled.
Low quality paints that are porous in nature will be more inclined to staining.
Use stain resistant coatings in areas that are prone to soiling.
Good quality water based emulsion sheen paints should be adequate for most applications. More specialised coating might be required for more aggressive contaminants.
Cracking Flaking Paint
What causes cracking /flaking paint?
The splitting of a dry paint film through at least one coat, which will lead to complete failure of the paint. Early on, the problem appears as hairline cracks; later, flaking of paint chips occurs.
Use of a lower quality that has inadequate adhesion and flexibility.
Overthinning the paint or spreading it too thin. Poor surface preparation, especially when the paint is applied to bare wood without priming.
Painting under cool or windy conditions that make paint dry too fast.
How do I fix it?
It may be possible to correct cracking by removing the loose or flaking paint with a scraper or wire brush, sanding to feather the edges, priming any bare spots and repaint with high quality acrylic.
Surfactant Leaching
What causes surfactant leaching?
Concentration of water-soluble ingredients on the surface of a latex paint, typically on a ceiling surface in rooms that have high humidity (e.g., shower, bathroom, kitchen); may be evident as tan or brown spots or areas, and can sometimes be glossy, soapy or sticky.
All latex paint formulas will exhibit this tendency to some extent if applied in areas that become humid (bathrooms, for example), especially in ceiling areas.
How do I fix it?
Wash the affected area with soap and water, and rinse. Problem may occur once or twice again before leachable material is completely removed. When paint is applied in a bathroom, it is helpful to have it dry thoroughly before using the shower. Remove all staining before repainting.
Chalking Paint
What causes chalking of paint?
Formation of fine powder on the surface of the paint film during weathering which can cause color fading. Although some degree of chalking is a normal, desirable way for a paint film to wear, excessive film erosion can result from heavy chalking.
Use of a low-grade, highly pigmented paint.
Use of an interior paint for an outdoor application.
How do I fix it?
First, remove as much of the chalk residue as possible, scrubbing with a stiff bristle brush (or wire brush on masonry) and then rinse thoroughly; or use power washing equipment. Check for any remaining chalk by running a hand over the surface after it dries. If noticeable chalk is still present, apply a masonry primer then repaint with a quality exterior coating.
Black mould, fungal or algae contamination
What causes chalking of paint?
Damp areas receiving little or no sunlight and poor ventilation are susceptible to mould. Painting over an area with previous mould and low quality coatings containing no or low levels of biocides. Reusing opened containers that have received contamination from application transfer and or storage conditions.
How do I fix it?
Determine firstly if the contaminant is dirt or mildew by applying an antifungal wash. Leave area for 24 hours so that the fungicidal can react and kill all the spores. Wash the surface with clean water and allow drying. Recoat with paint that is protected with dry film biocide.
Blistering/Bagging
What causes blistering or bagging of paint?
Blisters can be intact or perished and flaking. If not dried out the blisters can be found to be filled with water/liquid.
Excessive moisture ingress at back of paint film.
Painting too soon before the masonry structure has dried. Water based paint exposed to rain, high humidity or dew shortly after the coating has dried.
Poor structural design aspect related to moisture barriers.
How do I fix it?
Remove all loose and flaking paint.
Establish cause of moisture ingress and rectify.
Allow structure to dry out before repainting or if moisture source cannot be removed, a breathable coating may have to be used.
Efflorescence in Paint
What causes efflorescence in paint?
The formation of random white powdery salts on the surface which are generally more visible on darker coloured surfaces.
These salts are present in the sand used to make bricks and plaster. If moisture is present, the salts get washed to the surface and the paint film.
Failure to remove efflorescence before painting and or excessive continuous contact with moisture -areas most affected include parapet walls and horizontal landings or areas near ground levels and cracks.
How do I fix it?
Remove or seal the source of moisture ingress if this was the cause. Note: This is best done in dry seasons.
Remove efflorescence by brushing and power washing with copious amounts of water. Allow substrate to dry out for 2-3 weeks. If salts return the washing procedure should be repeated.
Apply an alkali resistant primer to the entire surface