Paint failure at joints and external corners of timber weatherboards

Causes

Moisture getting into the timber end grain

The cut ends of boards were not primed or sealed before installation

The timber has shrunk after installing causing joints to open

Listed under: Exterior, finishes, timber and wood-based, paint, timber, cladding, walls, moisture, leaks, wall cladding, painted timber weatherboards, lead-based paint

Cause

Moisture getting into the timber end grain

Repair

  • scrape and/or sand off loose paint; sand bare timber until the surface is sound; prime; fill joints with putty or exterior grade flexible (polyester) filler; paint with at least two coats of semi-gloss or high gloss acrylic paint
  • cover joints and/or corners with galvanised steel soakers (covers) or timber cover boards after priming to improve protection of the corners
  • where it is suspected that the building may be leaking and there is a risk of damage behind the cladding, engage an experienced building surveyor to report on the building 
  • caution: old layers of paint may contain lead. Lead can be a health hazard if fumes, dust or paint fragments are swallowed or breathed in. For more information see Health and safety: lead-based paint

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Cause

The cut ends of boards were not primed or sealed before installation

Repair

  • scrape and/or sand off loose paint; sand bare timber until the surface is sound; prime; fill joints with putty or exterior grade flexible (polyester) filler; paint with at least two coats of semi-gloss or high gloss acrylic paint
  • cover joints and/or corners with galvanised steel soakers (covers) or timber cover boards after priming to improve protection of the corners
  • where it is suspected that the building may be leaking and there is a risk of damage behind the cladding, engage an experienced building surveyor to report on the building
  • caution: old layers of paint may contain lead. Lead can be a health hazard if fumes, dust or paint fragments are swallowed or breathed in. For more information see Health and safety: lead-based paint

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Cause

The timber has shrunk after installing causing joints to open

Repair

  • scrape and/or sand off loose paint; sand bare timber until the surface is sound; prime; fill joints with putty or exterior grade flexible (polyester) filler; paint with at least two coats of semi-gloss or high gloss acrylic paint
  • cover joints and/or corners with galvanised steel soakers (covers) or timber cover boards after priming to improve protection of the corners
  • where it is suspected that the building may be leaking and there is a risk of damage behind the cladding, engage an experienced building surveyor to report on the building
  • caution: old layers of paint may contain lead. Lead can be a health hazard if fumes, dust or paint fragments are swallowed or breathed in. For more information see Health and safety: lead-based paint

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