Problem Solving (5)

1.Efflorescence (White Crystal Deposits)

White deposits of salts on paint surface that are migrating or leaching as water passes though the paint. This is often seen on masonry wall surfaces. Efflorescence will continue as long as moisture contaminated with salt that are present in motor, blocks, or concrete structures.

 

What causes it?

  • Failure to prepare and prime masonry surfaces adequately.
  • Leaching interior moisture through exterior masonry walls.
  • Heavy wind and rain promote exterior moisture driven through masonry walls.
  • Unsealed basement walls will allow ground water to penetrate.
  • Painting on sufficiently cured new plaster.

How to solve it?

  • Prevent moisture accumulation by replacing the damaged roofs, cleaning out gutters and downspouts, and sealing cracks.
  • Apply quality water proofing sealer to prevent moisture driven through the walls from outside.
  • Remove the efflorescence/ all loosen materials with a wire brush, power brush, or high pressure washing and allow to dry well.
  • Use quality alkali resisting sealer for alkaline masonry surfaces before painting.

 

 

2.Caulk (Paint Cracking or Crawling)

Cracking of the paint film over putty applied area.

 

What causes it?

  • Using putty that are not penetrable.
  • Painting on partial dried putty.
  • Caulking joints greater than 1/2”in width or depth.

How to solve it?

  • Apply caulk when rain or freezing temperatures exist in the surrounding and surface to be caulked.
  • Use bond breaker tape to caulk joints greater than 1/4”in width for maximum flexibility and performance.

 

 

3.Chalking (Powdering)

The formation of fine powder on paint surface due to weathering, which gives the appearance of colour fading. Natural paint weathering has some degree of chalking, but heavy weathering result for excessive erosion of paint film.

 

What causes it?

  • Using interior paint from outdoor application.
  • Not adequately sealing porous surface.
  • Paint over thinning.
  • Use of low-quality highly pigmented paints.

How to solve it?

  • Remove chalk using stiff bristle brush or wire brush rinse thoroughly or power wash.
  • If chalk is still present, prime with suitable masonry sealer.
  • Repaint with a quality exterior coating. If little or no chalk remains and the old paint is sound, no priming is necessary.

 

 

4.Cracking-Plywood (Checking)

Thin, long and relatively straight cracks that form in the paint film in the direction of plywood grain.

 

What causes it?

  • Changing moisture content in plywood tend to crack with its expansion and contraction.
  • Painting on insufficiently dried plywood.

How to solve it?

  • Newly installed exterior plywood should be sand and primed not allowing even for minimal exposure.
  • If cracking is not extensive, sand, wipe off dust, clean thoroughly, allow to dry well and prime with wood primer.
  • Replace severely cracked plywood.