Timber trims – peeling or flaking paint
Listed under: Exterior, finishes, timber and wood-based, paint, timber, cladding, walls, moisture, wall cladding, timber trims, lead-based paint
Cause
Thermal expansion and contraction of timber substrates
Repair
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scrape and/or sand off loose paint. Sand bare timber until surface is sound, then prime. Fill joints with putty or exterior grade flexible (polyester) filler. Paint with a minimum two coats of semi-gloss or high gloss acrylic paint
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select paint of a lighter colour where possible – darker colours attract heat, which can cause greater expansion/contraction of the timber, and thus a reduced lifespan for the paintwork
- 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
Cause
Loss of adhesion due to excess moisture in substrate
Repair
- scrape and/or sand off loose paint. Sand bare timber until surface is sound, then prime. Fill joints with putty or exterior grade flexible (polyester) filler. Ensure the timber is completely dry before painting. Paint with a minimum two coats of semi-gloss or high gloss acrylic paint
- 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
Cause
Poor initial substrate preparation
Repair
- scrape and/or sand off loose paint; sand bare timber until surface is sound; prime; fill joints with putty or exterior grade flexible (polyester) filler; paint with a minimum two coats of semi-gloss or high gloss acrylic paint
- 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
Cause
Oil-based (alkyd) paint applied over water-based (acrylic) paint
Repair
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oil-based paint should generally not be applied over water-based paint. To determine whether an existing paint finish is water-based or solvent-based:
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soak a cotton ball in rubbing alcohol (isopropyl or ethyl alcohol), an acetone-based nail polish remover or lacquer thinner
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rub it over a small, inconspicuous section of the trim
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if paint comes off, it is water-based; if unaffected, it is a solvent-based paint
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remove existing paint and sand bare timber until surface is sound. Ensure timber is thoroughly clean and dry, then prime. Fill joints with putty or exterior grade flexible (polyester) filler. Paint with a minimum two coats of semi-gloss or high gloss acrylic paint
- 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
Cause
Surface was damp or dirty when painted previously
Repair
- scrape and/or sand off loose paint. Sand bare timber until surface is sound, then prime. Fill joints with putty or exterior grade flexible (polyester) filler. Ensure the timber is completely clean and dry before painting. Paint with a minimum two coats of semi-gloss or high gloss acrylic paint
- 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
Cause
Dark colours
Repair
-
scrape and/or sand off loose paint. Sand bare timber until surface is sound, then prime. Fill joints with putty or exterior grade flexible (polyester) filler. Paint with a minimum two coats of semi-gloss or high gloss acrylic paint.
-
select paint of a lighter colour where possible – darker colours attract heat, which can cause greater expansion/contraction of the timber, and thus a reduced lifespan for the paintwork
- 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
Cause
Timber swelling/shrinkage caused by moisture absorption into timber end grain if joints were not adequately primed before installation
Repair
- scrape and/or sand off loose paint; sand bare timber until surface is sound; prime; fill joints with putty or exterior grade flexible (polyester) filler; paint with a minimum two coats of semi-gloss or high gloss acrylic paint
- 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
Cause
Coating is at the end of its serviceable life
Repair
- scrape and/or sand off loose paint; sand bare timber until surface is sound; prime; fill joints with putty or exterior grade flexible (polyester) filler; paint with a minimum two coats of semi-gloss or high gloss acrylic paint
- 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