Whilst it may sound like you are about to be supplied with instructions for measuring up your walls, “size” is actually the name given to a liquid that is painted over plaster before a wall covering in Melbourne is applied. This is supposed to help the covering adhere securely to the surface and to protect the plaster should it ever need to be removed. Follow these instructions for sizing your walls:
Step 1: Give the plaster a sponge down using water a dishwashing detergent to remove any dirt. Use clean water to rinse the detergent away, then allow the surface to dry. Make sure that you fill in any cracks or holes using a plaster filling compound; leave to dry and smooth using sandpaper.
Step 2: Take the sizing powder and place it into a bucket (following the instructions regarding how much you need). Pour some warm water into the bucket and stir until you have achieved a thick paste. Continue adding a little water at a time until the sizing resembles a thin latex paint. Leave to cure for around 45 minutes.
Step 3: Using a broad bristled brush, apply the sizing to the wall. Leave to dry, which should take around 30 minutes. You can then apply the wall covering, keeping in mind that the sizing will require you to use less paste.
You should only use size on plaster surfaces; for other materials (such as drywall or sheetrock), you should use an acrylic primer instead. Whenever you are buying size, check the ingredients for cornflower and starch – these actually encourage mildew growth behind wall coverings in Melbourne.