Peeling walls indicate the presence of a bond-breaking paint inhibitor, and the cause must be corrected before you repaint. Common paint inhibitors include soap, oil, grease, water, dirt and mildew. The walls should be stripped with a chemical stripper and sanded before you prime and repaint them. Stripping the wall completely will ensure a smooth painting surface. Preparing the walls for painting will take about 90 per cent of your time and effort, but the result will be a well-bonded coat of paint.
Lay painter's plastic down beneath the walls where the paint is peeling, and tape it to the floor with masking tape. Open a window and a door to allow for cross-ventilation. Set up a floor fan to circulate the air.
Pour two inches of paint stripper into a hand-held holder. Dip the bristles of a disposable paintbrush into the paint stripper and apply an 1/8 to 1/4-inch coating of stripper around the perimeter of each wall. Apply the stripper boarder 4-inches wide from the wall's edges.
Pour a half-gallon of paint stripper into a paint tray on top of the painter's plastic. Put the 1 1/2-inch nap roller cover over the spindle of the 9-inch roller frame, and screw the extension pole into the end of the roller handle.
Dip the fibres of the roller nap into the paint stripper and load them with stripper by rolling the roller back and forth on the paint tray. Roll up and down the walls into the previously brush-applied stripper until each wall is layered with a 1/8 to 1/4-inch layer of stripper. Allow the stripper to work on the paint for 24 to 48 hours, until all of the peeling and intact paint has bubbled and peeled away from the subsurface.
Grip the handle of the putty knife and hold it to the wall at a 45-degree angle. Scrape the blade edge across the wall to lift away all peeling paint. Continue to scrape until the stripped peeling and bubbling paint is completely removed. Scrape the stripped gunk off of the blade of the knife into an empty paint can. Scrape up and down and from side-to-side until the subsurface has been exposed. Wait 24 hours.
Attach a piece of 150-grit sandpaper to a pole sander, and sand the walls until all paint and stripping residue has been completely sanded off.
Go over the sanded wall with a tack cloth to remove all dust debris.
Pour two inches of an all-surface stain-blocking primer paint sealer into a hand-held paint holder. Dip a paintbrush into the sealer, and paint the borders around the walls, just as you did with the stripper.
Pour a half-gallon of oil-based stain-blocking primer paint into the paint tray. Put a 1/2-inch-nap roller cover on the spindle of the roller frame, and dip it into primer until the fibres are loaded with primer. Roll the walls with primer until each wall is covered with an even layer of primer paint sealer. Allow the primer to dry for 24 hours. Look for peeling primer during this time. If the primer begins to peel, then the entire wall will need to be skim-coated with drywall compound.
Apply a layer of finish paint by painting the wall edges with the brush and then rolling the walls out with a 1/2-inch nap roller. Wait 24 hours, and apply a second coat.
If only a small area of paint is peeling, sand the peeled paint smooth with 120-grit sandpaper. Skim the uneven surface with a layer of drywall joint compound using a 5-inch putty knife. Prime and paint the patched area with a paintbrush or mini roller.
Wear a paint respirator when using paint stripper, as the vapours are harmful when inhaled. Wear chemical resistant rubber gloves to protect hands and fingers from chemical burns. Wear eye goggles to protect eyes from chemical burns.