Need to paint a wall but don't know where to start? Step one is to prep your walls for painting. Depending on the type of wall surface you're painting, you'll need to do different things. In this handy guide we'll walk you through the best way to prep different walls for painting and provide some preparation and painting tips for each type of wall.

Painted plasterboard walls

Sometimes called "gyprock" or (for Americans) "dry-wall", plasterboard is a ubiquitous construction material and most houses built after 1960 have at least a few plasterboard walls. The majority of internal walls in newly constructed houses comprise a timber frame ("stud wall") and plasterboard (see the next section for preparing unpainted plasterboard walls).

Spot clean any marks or stains with a damp cloth and either clean water or sugar soap. Don't use anything abrasive and try to avoid using strong cleaning chemicals that might alter the plasterboard or paint surface. Your undercoat should hide any minor marks or stains but the use of solvents can prevent subsequent coats of paint from adhering properly to your wall surface.

Lightly sand the wall in any areas where there is previous paint (that might be the whole wall) using a fine-grit sandpaper to remove any imperfections and ensure a smooth surface for new paint. Wipe the wall down with damp clean cloth to remove excess dust. If you want to approach your paint job like a professional would, you can pick up a dustless sanding system from Mirka.

Once you have a clean surface, paint the walls with a good quality undercoat. If the walls are painted in a darker colour than the new colour you have picked, you'll need something with good stain and colour hiding qualities. We recommend choosing a quality 3-in-1 sealer, primer and undercoat product like Cosmocoat 3-in-1 Prep.

Unpainted plasterboard walls

In brand new homes, or in homes where renovations have recently been completed, new and unpainted plasterboard walls may need to be painted. Using specialist plasterboard filler like Uni-Pro's Interior Filler, fill any gaps between boards completely and fill any holes created by the nails used to hang the boards.

To produce a smooth finish and avoid an uneven finish, sand the surface with coarse-grit sandpaper and then fine-grit sandpaper. Make sure to clean walls of any dust with a damp cloth.

As with painted plasterboard walls, unpainted plasterboard can be readied for paint with a good quality 3-in-1 sealer, primer and undercoat and our pick is Cosmocoat 3-in-1 Prep.

Brick walls

Bare brick walls in older houses can often be affected by fluorescence (white, chalky build-up on the brick surface) or mildew (dark green-black patches on the brick surface). You can use a solution of 10:1 water and hydrochloric acid to wash bricks, scrubbing with a bristle brush once the chemical reaction has finished and washing thoroughly with water. Follow the instructions on the container of your acid (or any other chemical product) and pay attention to all safety warnings and guidelines.

Bricks have a porous surface, so allow your brick water to dry completely before painting. If you plan to white-wash your brick walls you'll need to choose a self-priming paint that can be applied to an non-primed surface and then washed to achieve that particular look. If you are planning to paint over your bricks with a solid colour, a sealer and primer with strong adhesive qualities is best.

Painted brick walls should be scrubbed clean with a bristle brush and surface cleaner. Avoid solvents designed to remove or strip paint unless you plan to remove all paint from the surface of the wall (a long and complicated process). Once dry, apply a high-adhesion surface preparation sealer and primer.

Great brick wall primer options include Taubmans Advanced Adhesion and Mould Blocker and Dulux Precision Maximum Strength Adhesion Primer.

Concrete walls

Concrete walls are less common as internal walls in homes, but concrete retaining walls, external support walls, and exposed sections of concrete slab can be painted in much the same way as other walls.

If your concrete wall has an old layer of paint, start by scraping off any loose paint or paint flakes. You can use a paint scraper, palette knife or bristle brush. Rough surfaces or uneven surfaces can be difficult top clean, but it's worth taking the time to make sure all loose material is removed.

Next your concrete walls with warm water, soapy water, or sugar soap (depending on level of cleanliness). You can use more abrasive materials and chemicals on concrete surfaces, but avoid things like hydrochloric acid which will etch or scar concrete and remove the smooth "troweled" surface layer of your concrete and expose rough aggregate underneath.

Fill any cracks, gaps or holes with concrete grey filler applied using a caulking gun and then sand with fine-grit sandpaper until smooth. Rust-Oleum Concrete Patch and Repair is a great option.

To produce a professional finish when you paint concrete, apply a preparatory coating first. In areas of high moisture (including bathrooms, kitchens and outdoor areas), Dulux Precision Stain and Mould Blocker is highly recommended. Elsewhere, Dulux 1Step Prep is great for concrete surfaces.

Wallpapered walls

Wallpaper is no longer a popular wall covering and very few new houses feature wallpaper. With prices starting at around $80 per roll, it is also a considerably more expensive option in Australia. More often than not, if you have wallpaper and you want something else, you'll need to remove the wallpaper first.

There are a number of wallpaper removal products on the market, but whichever you choose, make sure you clean your walls with Krud Kutter Gloss-Off PrePaint, which is specifically designed to remove wallpaper glue residue from surfaces you intend to paint.

From there, follow the tips above depending on your wall surface. Most often wallpaper was applied to painted plasterboard walls or painted timber panels, which can be prepared the same way.

Time to paint

These tips should help you prep your walls for painting, but if you need additional advice or guidance, have a chat with the experts at PaintAccess. You can also buy any of the products references in this guideline from or in-store in Sydney at St Leonards or Matraville.

Now that you're ready to paint we have several painting guides that can help you paint feature walls, interior and exterior walls, and a range of other surfaces.