Plywood cladding – bubbling or blistering paint/stain
Causes
A loss of adhesion due to excess moisture in the substrate
Poor initial substrate preparation
Oil-based (alkyd) paint applied over water-based (latex) paint
Surface was damp or dirty when painted previously
Dark colours increasing surface temperatures
Water-based paint coat exposed to moisture before paint has fully dried
Listed under: Exterior, timber and wood-based, plywood, cladding, walls, moisture, wall cladding, plywood sheets or planks
Cause
A loss of adhesion due to excess moisture in the substrate
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 a minimum two coats of semi-gloss or high gloss acrylic paint
- if blistering goes through to the substrate, it indicates that there is a high moisture content in the timber and this must be addressed before repainting.
Cause
Poor initial substrate preparation
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 a minimum two coats of semi-gloss or high gloss acrylic paint
- if blistering goes through to the substrate, it indicates that there is a high moisture content in the timber and this must be addressed before repainting.
Cause
Oil-based (alkyd) paint applied over water-based (latex) paint
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 a minimum two coats of semi-gloss or high gloss acrylic paint
- if blistering goes through to the substrate, it indicates that there is a high moisture content in the timber and this must be addressed before repainting.
Cause
Surface was damp or dirty when painted previously
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 a minimum two coats of semi-gloss or high gloss acrylic paint
- if blistering goes through to the substrate, it indicates that there is a high moisture content in the timber and this must be addressed before repainting.
Cause
Dark colours increasing surface temperatures
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 a minimum two coats of semi-gloss or high gloss acrylic paint
- if blistering goes through to the substrate, it indicates that there is a high moisture content in the timber and this must be addressed before repainting.
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 the 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
- if blistering goes through to the substrate, it indicates that there is a high moisture content in the timber and this must be addressed before repainting.
Cause
Water-based paint coat exposed to moisture before paint has fully dried
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 a minimum two coats of semi-gloss or high gloss acrylic paint
- if blistering goes through to the substrate, it indicates that there is a high moisture content in the timber and this must be addressed before repainting.