If you have a home or building affected by flooding or water damage from a storm, it can be tempting to clean it up and paint over it as fast as you can. However, it is best to allow the home or building plenty of time to fully dry out, before undertaking any redecorating.
Generally the best place to start will be with a good clean of the surface using a product like Resene Paint Prep and Housewash (see Data Sheet 812). This will do a much better job than water alone. Mud and silt will need to be removed from wall cavities, any damaged areas repaired and then all left to dry before any painting is considered.
Once the exterior area is dry, remove any flaking paint using a scraper and fill all cracks with either sealant or plaster depending on the size of the cracks. Depending on the surface you may need to prime first or you may be able to go straight to a Resene decorative topcoat like Resene Lumbersider waterborne low sheen (see Data Sheet D34). For higher sheen finishes you could opt for Resene Sonyx 101 semi-gloss waterborne (see Data Sheet D30) or Resene Hi-Glo gloss waterborne (see Data Sheet D31). If you are repainting in a dark colour, consider using a Resene CoolColour™.
Paths, driveways and other concrete areas can also be treated with Resene Moss & Mould Killer (see Data Sheet D80) to kill mould and cleaned with Resene Housewash and Paint Prep (see Data Sheet D812). Timber decks can be treated with Resene Moss & Mould Killer to kill mould and cleaned with Resene Timber and Deck Wash (see Data Sheet D814). Once any moss and mould is treated and the deck is clean, stained wooden decks can be re-stained by applying a wood stain such as Resene Woodsman Wood Oil Stain (see Data Sheet D57), Resene Woodsman Decking Stain (see Data Sheet D57D) or Resene Kwila Timber Stain (see Data Sheet D501).
If water has entered your home or building, it may have irreversibly damaged plasterboard walls and they may need to be replaced, along with new skirting boards and architraves.
Allowing everything to dry out will give you a clearer idea of what needs repairing or replacement and which areas that just need redecoration.
Clean existing painted areas with Sugar soap to remove accumulated dirt, dust and marks. If the interior has been exposed to water and even once dry, it is likely that mould growth will be an issue. Thoroughly clean all painted areas with a product like Resene Moss & Mould Killer to kill the existing mould. Where possible move everything out of the area you are planning to clean before you start to make it easier to complete the work without damaging any of your possessions.
Remove any flaking paint using a scraper and fill all cracks with either sealant or plaster depending on the size of the cracks. Sand glossy surfaces to provide a key for the paint finish.
Apply a primer or sealer over the whole area to be painted to seal in existing stains and provide a surface suitable for further coats of paint. Topcoat with Resene SpaceCote Low Sheen (see Data Sheet D314) or Resene Zylone Sheen (standard or no added VOCs, see Data Sheet D302) in living areas and Resene SpaceCote Low Sheen or Resene Lustacryl semi-gloss waterborne enamel (see Data Sheet D310) in wet areas. Finish ceilings in dry areas in a flat finish like Resene SpaceCote Flat (see Data Sheet D314) or Resene Ceiling Flat (see Data Sheet D305). Ceilings in kitchens and bathrooms are best finished in Resene SpaceCote Flat. Paint trim and joinery in Resene Lustacryl semi-gloss waterborne enamel or opt for the higher gloss of Resene Enamacryl gloss waterborne enamel (see Data Sheet D309).
Once fully dried out you can repair and redecorate as you would normally. You might like to consider getting Resene MoulDefender mould inhibitor added to any Resene waterborne decorative paint you use as it helps to inhibit moss and mould growth.
Any existing moss and mould will need to be treated before you repaint, using a cleaner such as Resene Moss & Mould Killer (see Data Sheet D80). If moss and mould are not killed prior to repainting then will grow through the subsequent paint finish and ruin the look of the fresh paintwork.
To check the paint is sound, do an adhesion test. Cut a small X shape through the existing paint with a sharp knife or blade, press clear tape firmly across the X shape then rip it off. If the tape comes away clear the surface is sound. If the tape comes off and the paint comes too, it is unsound and will need to be stripped before the surface is painted.
Contact your local Resene ColorShop or Reseller for advice.