Have you ever completed a paint project and then found bubbles, blisters, cracks, flakes, a powdery white substance or mildew on the surface? What went wrong? How do you correct it? When the preparation and/or application of paint (interior or exterior) has been less than ideal, a number of problems can occur. The following are the origins and solutions for some common problems with paint.


Blisters or Bubbles: Small to medium-sized bubbles or blisters under the paint film. 

  • Causes:
    • painting when humidity is high
    • applying paint to a damp surface
    • applying paint to a hot surface
    • re-coating too quickly
    • insufficient surface preparation
    • poor quality paint and/or primer
  • To Avoid:
    • avoid painting under extreme humidity or if a high dew point is present 
    • make sure your surface is dry and free of moisture before the paint application
    • allow adequate drying time before re-applying paint
    • avoid painting exterior surfaces when hot to the touch
    • choose the correct primer for the type of surface to be painted
    • use high-quality paint
  • To Repair:
    • scrape away blistered paint 
    • sand to bare wood
    • let wood completely dry before repainting


Chalking: A fine, powdery white substance that forms on painted exteriors.

  • Causes:
    • using a product that contains a high amount of extenders
    • over thinning your paint
    • improper paint (such as interior paint used in an exterior application)
    • not properly sealing a porous surface before painting
  • To Avoid:
    • apply high-quality paints at the recommended spreading and thinning rate
    • seal porous surfaces with a high-quality product before painting
    • use the appropriate paint product for the situation
  • To Repair:
    • eliminate all evidence of chalking by power washing or treating with TSP solution
    • allow to dry thoroughly before repainting with high-quality paint


Cracking and/or flaking: Vein-like lines that appear through the paint and become jagged flakes.

  • Causes:
    • insufficient surface preparation
    • over-thinning your paint 
    • too thick of paint
    • inadequate drying time between coats
    • use of low-quality paint
    • skipping the primer
  • To avoid:
    • adequately prepare the surface
    • let the paint dry for the recommended time before recoating
    • use high-quality paint and primer
    • apply paint and primer at recommended spreading and thinning rate
    • If using a brush; allow the paint to cover only one-third of the bristle length of your brush, tap the brush lightly on both sides, avoid dragging the brush against the edge of the container
    • If using a roller; fill the roller tray halfway, remove lint from a new roller cover, dip the roller into the well of the tray, then over the ribbed portion of the tray, repeating several times to evenly distribute the right amount of paint
  • To Repair:
    • remove all cracked and flaking paint with a scraper, wire brush, heat gun, or chemical application (depending on the extent and severity of the problem)
    • sand, feathering the edges to blend 
    • clean the surface
    • prime the surface
    • repaint problem spots, taking care to load the brush or roller properly to avoid too-thin or too-thick application


Mould and Mildew: Black, grey or brown spots on the surface of the paint and/or caulk.

  • Causes:
    • occurs in damp areas (bathrooms, kitchens, laundry rooms, soffits, eaves)
    • use of low-quality paint
    • failure to prime wood
    • painting over existing mildew/mould
  • To Avoid:
    • use a high-quality paint with a mildewcide
    • remove existing mildew/mould with a bleach solution before painting (one part bleach, three parts water)
    • prime wood before painting
    • install an exhaust fan in high moisture areas
  • To Repair:
    • scrub with TSP or a bleach solution
    • leave the solution on the area for 10 to 15 minutes
    • rinse
    • wash area with detergent solution
    • rinse again
    • let dry
    • repaint with a high-quality product containing mildewcide


Many common paint problems can be avoided by proper preparation of the surface and the use of high-quality paint and primer. To ensure you meet these requirements, call a professional painting company. They have the knowledge, skill and experience to make sure your paint job is done right. Save yourself time and effort! Have it done correctly the first time!

Want to avoid paint problems? Need a professional painting company? Call the Calgary residential painting experts, Cal Res Coatings at (403) 835-4817. We have experience with exterior and interior painting. We’re a residential painting contractor that strives for quality, has an eye for detail and colour, and will not rest until your job is done to your satisfaction. Request a free quote today.

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