HAZARDS FROM LEAD HAZARDS FROM ASBESTOS REMOVE OLD, DAMAGED PAINT OR STAIN GET RID OF MILDEW CLEAN THE AREA PREPARE GLOSSY SURFACES SELECT THE PRIMER CHECK ALL SEALANT ADDITIONAL TIPS FOR SPECIFIC BUILDING MATERIALS Rule number one: you can’t just paint over dirt, mildew, and old, cracked paint – unless you want to paint again soon. So the first thing you need to do is examine the surface you’re planning to paint. Check for mildew, peeling paint or stain, and follow the steps below to prepare the surface properly. TIP: Allow plenty of time for preparing the surface. It will probably take longer than the actual painting. WARNING:  Be sure to take the appropriate precautions when preparing surfaces which may contain harmful materials such as lead or asbestos. See our recommendations in the section below. The paint on old houses or buildings may contain lead pigments. White lead was used in house paints until the mid-1950s, and red lead was commonly used in primers until the 1980s. Lead chromate pigments were used in some red, yellow and orange colours, and calcium plumbate pigment was used on galvanised iron and steel structures up to the 1980s. Lead test kits can be purchased from specialist paint stores. If possible, the old lead-containing paint should be left undisturbed and simply cleaned and repainted. However, if you are removing lead paint inside: Remove curtains and furniture and, if possible, remove or fully cover carpet. Close doors to other rooms. Use drop sheets to catch debris. Regularly clean up debris. Wipe down all ledges, sills etc. with a damp cloth, and vacuum floor to remove dust. Place in garbage bag for disposal. Dealing with the Dangers of Asbestos Before 1983 most fibrous cement sheeting and roofing and some textured coatings contained asbestos. Asbestos fibres present a serious health hazard if they are disturbed and inhaled during cleaning, repainting or removal. Therefore cleaning or removal of mould and moss should be done WITHOUT sanding, wire brushing or scraping so as not to create a dust. Wash down with a low pressure garden hose. If the fibrous cement sheet cannot be prepared or painted without disturbing the surface, a sample should be tested for the presence of asbestos. Contact your state EPA or Worksafe (National Occupational Health & Safety Commission) in Australia, or the Department of Labour, Occupational Safety and Health in New Zealand, who will recommend a testing laboratory. If it is proved that asbestos is present, and the surface will be disturbed during the work, then a handling procedure recommended by the EPA or Worksafe (OSH in NZ) must be followed. For large jobs, it is recommended that a trained specialist contractor, approved by Worksafe, be engaged to conduct the work.     REMOVE OLD, DAMAGED PAINT OR STAIN You may have to combine a few different methods to get the job done right. Review the methods explained here and see which ones best suit your project. SCRAPING Scraping is most effective on flat surfaces, from smooth masonry and hardboard to wood and ferrous metal. Make sure the scraper is sharp and apply even pressure as you scrape in one direction; then scrape at 90 degrees. Shaped scrapers like triangles and ovals make it easier to get into corners and to scrape rounded profiles. Be sure NOT to apply pressure when scraping hardboard. For the really tough jobs, like hard or metal surfaces, try a two-hand scraper. When the scraping is done, feather sand rough edges of remaining paint with a medium grit sandpaper such as #100 grit. Wear goggles or face mask for eye protection. Wear leather or work gloves to protect the skin. Use a protective mask or respirator to limit dust intake. WIRE or STIFF BRISTLE BRUSHING Use a stiff metal hand brush on brick, stucco and other masonry and on wood shakes (in a vertical motion). Power wire brushing is for stubborn areas only and must be used with extreme care. Wear goggles or face mask for eye protection. Wear leather or work gloves to protect the skin. Use a protective mask or respirator to limit dust intake. FILLING Cracks or holes in the old paint film or in the substrate should be filled before final sanding. Choose a filler suitable for the type of substrate you are painting over. For example, over exterior timber, select a flexible acrylic wood filler. For surfaces like brick or render, choose a specialist masonry filler appropriate for the size of crack or hole to be filled. When the filler has fully dried, a second application of filler may be required if the hole is deep and the first application has not completely filled it to a level surface. Once fully dry, the filler can be sanded smooth. SANDING Areas that have been scraped and filled should be smoothed with sanding. A power sanding tool like an electric belt sander is an option when the substrate is wood or steel. Do not attempt to power sand masonry, hardboard, aluminum or plastic materials. POWER WASHING A high-pressure plain water stream held 150mm to 200mm from the surface will lift old, loose paint. Never use harsh cleansers or bleach! Always spray at a horizontal or downward angle. An upward angle can damage cladding. Be careful around doors & windows since the spray may have enough force to shatter glass and damage seals. Do not use power washing on soft woods like cedar and redwood. Wear goggles and water-repellant clothing and footwear. CHEMICAL REMOVAL Strong solvent-based removers work well on most oil-based and latex paints, primers, stains, and varnishes. Chemical removers should be used only on small face-up areas such as trim and moldings. Make sure to select a chemical remover that is intended for your application. Use with extreme care and follow these directions: -- Before you begin, clear the area of children and pets and extinguish any fire sources. -- Cover floors and steps and remove plants, rugs and furniture. -- Apply a heavy coat to a small area (about 1 sq. m) with a low-end natural bristle paint brush. -- Allow plenty of time for it to work (see manufacturer’s recommendations). -- Carefully remove the softened coatings using a putty knife or wooden blade and scrape the materials into a cardboard carton. -- Reapply more stripper if needed. -- Clean the surface with wadded up paper towels. Do not use steel wool; it can discolour the surface. -- Dispose of all refuse after the job, carefully following manufacturer’s instructions. IMPORTANT: Wear goggles or face mask and long sleeve shirt and long pants. Use chemical-resistant gloves and a respirator designed for use with chemical solvents. Follow all direction and safety precautions. Some products are highly flammable and all fire sources must be extinguished prior to use. There are low odour solvent removers, but since they are not as strong, they may take much longer to work. HEAT GUN A heat gun designed for paint removal – NOT a propane torch or blow torch – can be a good way remove old exterior paint and varnish. Follow these steps for a safe, effective job: -- Place a drop cloth under the entire work area. -- Keep the drop cloth damp by spraying regularly with a garden hose. -- Spray a light coating of water on the area where the paint is to be removed. -- As the old coating bubbles and softens, carefully remove it with a putty knife and place it in a metal container for disposal. IMPORTANT: Wear goggles or face mask and long sleeve shirt and long pants. Use chemical-resistant gloves and a respirator designed for use with a heat gun. Do not remove old paint with a heat gun if you suspect it contains lead! The heat can vaporise the lead and cause a health hazard. Please refer to the instructions on handling lead earlier on this page. <<TOP<<   GET RID OF MILDEW What is mildew? It’s that spotty black, grey and brown mold that grows in warm, moist, low-light environments. Before you paint, look for mildew in areas that get little or no sun, like around the trim, under eaves, northern exposures and shaded areas. Can you paint or stain over mildew? No! The paint or stain may cover it at first, but before long the mildew will grow right through the new coating. How do you get rid of it? It isn’t easy, but it can be done. Here’s how: -- Prepare a 3:1 mixture of water and household bleach (3 parts water to 1 part bleach). -- Sponge the mixture on the mildew, covering a 1 – 2 foot area around the mildew. -- Allow it to remain on the surface for at least 20 minutes, and reapply as it dries. -- Rinse thoroughly with water. -- Then wash the area with a mild detergent and rinse with water again. Always wear goggles, rubber gloves and old clothes when working with bleach. Never mix bleach with ammonia products. The combination can release poison vapors. <<TOP<<   CLEAN THE AREA Paint adheres better to a clean surface. Use detergent, water and scrub with a stiff bristle brush. Rinse the surface thoroughly and allow to dry completely before priming. If the surface is extremely dirty, power washing is extremely effective. A high-pressure plain water stream held 150mm to 200mm from the surface will wash away surface dirt.. Never use harsh cleansers or bleach! Always spray at a horizontal or downward angle. An upward angle can damage siding. Be careful around doors & windows since the spray may have enough force to shatter glass and damage seals. Do not use power washing on soft woods like cedar and redwood. Wear goggles and water-repellant clothing and footwear. <<TOP<<   PREPARE GLOSSY SURFACES Glossy areas should be dulled or paint/primer will not adhere well. -- Sand with a medium grit paper such as #100 - #120. Use fine grit paper (#180 - #220) for critical work such as doors and prominent trim. -- Then remove any dust with a damp rag. Chemical deglossers are available, but require care and caution. Leaving a chemical deglosser on the surface too long can soften and wrinkle the old coating. If you use a chemical deglosser: -- Make sure there is ample ventilation. Open windows and use fans. -- Follow manufacturer’s instructions carefully. -- Exercise safety precautions – protective goggles & clothing, gloves, respirator. <<TOP<<   SELECT THE PRIMER What does a primer do? A primer helps the new coat go on easier, look better and last longer. It ensures a more uniform look. As a general rule, any previously unpainted or unstained surface should be primed. Also, if the surface is very porous, or is uneven in porosity, a primer is recommended. You may even want to use a primer over a sound panted surface to ensure better adhesion and uniformity of the new coat. Depending on the surface, a special stain-blocking primer may be necessary. Latex or Oil-Based Primer? Oil-based primers usually provide superior stain-blocking. How to choose: It’s simple, really. Make sure you know what kind of surface(s) you’ll be coating and choose a primer that is specially formulated for that surface (wood, masonry, hardboard, metal substrates). Be sure to use an exterior primer for exterior work. Be sure to read and follow all manufacturer’s recommendations!!! <<TOP<<   CHECK ALL SEALANT What is sealant? Sealant is used to seal areas where there are gaps in materials or where there were openings for pipes, wires and light fixtures. Sealant keeps out the elements and insects and gives the house a neat, finished look. Chances are, it it’s time to repaint, it’s also time to re-seal. What to look for: Check all the sealant and remove any that is old, cracked or pulled away from the surface. Scrape the area and dust before priming if the area is to be painted. Choosing the right sealant: Use acrylic or siliconised acrylic sealant for exterior use. For areas where building materials meet that are not to be painted, use a clear acrylic sealant for cosmetic purposes. Silicone sealant is also good for exterior use, but should not be painted over. What to do: Apply fresh sealant to all cracks and opening up to 12mm wide. Allow to dry overnight and re-apply as needed. <<TOP<<   ADDITIONAL TIPS FOR SPECIFIC BUILDING MATERIALS BARE WOOD Any wood that has weathered more than a few weeks should be thoroughly sanded. Remove all grey colouration on the surface and dust thoroughly. Follow the same procedure for any surface exposed by peeling paint. Fill any cracks with a flexible acrylic wood filler, then sand and prime the bare wood with a quality acrylic exterior primer formulated for wood. Alternatively, on most timbers, a premium self-priming 100% acrylic top coat can be used without the need for a primer. Follow the manufacturer's recommendations. TREATED LUMBER It is important to allow treated lumber to cure before painting, in order to allow moisture from the treatment process to evaporate. It typically takes several weeks after construction, depending on the dimensions, humidity levels, and other weather factors. This is especially important if you're using oil based primers and paint products. Sand away any shiny mill glaze on wood, dust and prime and paint or stain promptly. ALUMINIUM CLADDING You're likely to encounter a chalky residue on weathered aluminium cladding which can be removed by scrubbing with a mild detergent and rinsing, or power washing. A second treatment may be needed. Any white oxide should be scrubbed away with a non-metallic scouring pad like Scotch Brite, and then rinsed with water. Apply a latex metal primer to bare metal or oxidised areas before painting. IRON, STEEL, GALVANISED METAL To prepare these metal surfaces, remove as much existing rust as possible with a wire brush. Then clean the surface. The appropriate primer is a corrosion inhibitive acrylic or oil-based formulation applied according to the manufacturer's directions. When brushing be sure to use protective goggles, clothing and a mask or respirator. MASONRY Loose paint, dirt , sand, and efflorescence (residue from water infiltration) should be removed with a stiff wire hand or power brush. If there is efflorescence present, find and eliminate the water source. Smooth concrete surfaces should be etched with a muriatic acid solution. Follow manufacturer's instructions and safety precautions carefully and rinse thoroughly. Apply a sealer or primer recommended for masonry if surface is less than a year old or is very porous. <<TOP<<