Previously painted surfaces: Test if surface is sound by cutting a small X through the existing paint with a sharp blade, press cellulose tape firmly across the cut and then rip off the tape. If the paint comes off, it is unsound and should be removed. Repeat at random in a number of areas to test the surface. Clean with Dulux Prep Wash. Scrape off all loose and flaking paint. Fill any cracks or holes with a suitable exterior filler. Dulux recommends Selleys products. Sand all surfaces to a flat finish and remove greyed timber. Dust off. Pre-primed timber and fibre cement: Preparation can vary depending on the quality and condition of the substrate. For help and advice call NZ 0800 800 424 . Bare (unpainted) timber: Fill nail holes with a flexible, exterior grade wood filler. Dulux recommends Selleys products. Sand all dressed timber and remove greyed timber. For hardwoods, apply one coat of Dulux 1Step® Prep for improved resistance to cracking. Bare brick, masonry, fibro and fibre cement board: Unpainted masonry surfaces should be cured for 28 days before painting. Ensure surface is clean and clear of any loose sand or cement. Fill holes with grouting cement. Wash down with water using a stiff brush to remove all loose material. To remove any efflorescence (white salts) wipe down with a 5% solution of acetic acid (white vinegar). Hose down and allow to dry. Wash with a bleach solution and/or demossing chemical to remove mould or moss, then hose down. Galvanised iron: Clean with a scouring pad and Selleys Sugar Soap solution. Thoroughly hose off. For surfaces within 1km of the sea, and some bases, apply one coat of Dulux PRECISION® All Metal Primer. Colorsteel®: Preparation requirements can vary depending on the condition of the substrate. For help and advice call NZ 0800 800 424. ZINCALUME®: Clean with Selleys Sugar Soap solution. Thoroughly hose off. For surfaces within 1km of the sea, and some bases, apply one coat of Dulux PRECISION® All Metal Primer. Steel and wrought iron: Remove all rust by scraping, sanding or wire brushing. Apply two coats of Dulux PRECISION® All Metal Primer.