Painting Tips

How much paint do you need?
Measure the perimeter (width of each wall) of the room. Then multiply the perimeter total by the height of the walls
e.g. Perimeter 20 feet + 20 feet + 12 feet + 12 feet
Width =   64 feet
Height = x 8 feet
512 sq ft
One gallon of paint covers approximately 400 square feet.
Therefore this room would require about 1.5 gallons of paint to complete.


Why is surface preparation important?
Inadequate surface preparation is the biggest single reason why paint failures occur. Depending on the condition of the surfaces being painted, proper surface preparation might include cleaning, repairing, patching, sanding, masking and priming. The following steps below describe in general detail, surface preparation for both interior and exterior painting:

Interior Surfaces: These must be free of dust, dirt and grime. Repair all gouges, cracks, holes etc, and sand the surface smooth.
Exterior Surface: These must be thoroughly cleaned of dirt, sap, mildew and any other substances that might inhibit adhesion or take away from the overall appearance and durability of the finish. Ensure that all loose and peeling paint are removed.


When is priming necessary?
Some surfaces must be primed before painting, to ensure the best possible results. Primers are normally used for one or more of the following reasons:

  • To fill and seal the pores in surfaces like bare wood or weathered masonry.
  • To provide a smooth, even surface for the finish coat, especially for enamel topcoats.
  • To cover the substrate, so the topcoat will hide better.


What Primer should be used on new walls on the Interior?
Concrete Primer thinned in a ratio of 4 parts primer to 1 part clean water may be applied before 2 coats of emulsion on interior walls


What Primer should be used on new walls on the Exterior?
For best results and true colour retention, Alkali Resisting Primer should be used as the primer.


What Primer should be used on new wood to be varnished?
For Vertical Surfaces: One (1) coat Sissons Sanding Sealer, which is clear.
For Horizontal Surfaces: Sissons Polyurethane or High Gloss Varnish as the first coat.


What Primer should be used on new wood to be painted?
Sissons Universal Undercoat, which is white


Can Emulsion Paint be applied to surfaces already varnished or painted with Oil Gloss Paints?
Yes, Sand the surface with a fine grade sandpaper, remove residue and apply a coat of Sissons Universal Undercoat. Allow to dry thoroughly before applying emulsion.


When can new walls be painted?
New masonry should be allowed to dry out (cure) for 6 weeks before primer is applied.


What causes mildew?
Mildew is an airborne fungus that can grow on most surfaces, including painted ones. It can be black, gray, green or brown in color, and may look like dirt on the surface.
Mildew requires moisture, warmth, a food source and a surface in order to grow; the following conditions will increase the chances of mildew growth:

  • Warm, humid conditions
  • Poor air circulation
  • Protection from direct sunlight
  • Proximity to existing mildew


What causes peeling?
Peeling is the final result when a paint film loses its adhesion to the substrate due to moisture and inadequate surface preparation. Peeling may occur between coats of paint (intercoat failure), or all the paint coats may peel from the underlying substrate (total film failure).

  • Poor surface preparation – The following surface conditions may cause peeling if not prepared properly:
    1. Slick, glossy or non-porous surfaces
    2. Dirty, greasy or grimy surfaces
    3. Chalky surfaces
    4. Rusty or corroded metal
    5. New alkaline masonry
    6. Porous, weathered wood
    7. Galvanized metal
    8. Unsound surfaces (like loose, crumbling masonry, or surfaces with peeling or flaking paint or multiple paint coats)
    9. Damp surfaces


  • Application conditions – Peeling can also occur if the paint is applied in less than ideal conditions:
    1. If the temperature is too hot or cold, incomplete film formation may result in poor adhesion.
    2. If the paint is applied to a wet or damp substrate, or applied when the humidity is too high.


What can I do about peeling?

  1. Remove the peeling sections of paint, by scraping or wire brushing and lightly sand the surface to a smooth finish.
  2. Dull any glossy surfaces with light sanding using fine-grit sandpaper.
  3. Remove any sanding dust, ensuring a clean, smooth surface.
  4. Apply the appropriate primer, as per label instructions.
    • Metals: use a Red/Yellow Zinc Oxide
    • Woods: use Sissons Universal Undercoat
    • Concrete: use Sissons Alkali Resisting Primer
  5. Repaint the surface when the temperature and humidity is suitable for painting.
    i. Metals: Alkyd or Oil-based paint
    ii. Woods: Sissons Super Gloss
    iii. Concrete: Sissons Super Matt or Weather Guard