Maintaining surfaces

 

How often you must repaint or recoat a surface depends on three factors: how often you use it, its location and the type of coating involved (transparent or opaque).

How often you must repaint or recoat a surface depends on three factors: how often you use it, its location and the type of coating involved (transparent or opaque).

Horizontal surfaces tend to retain water and are exposed for longer periods to the sun. You should apply new coatings to such surfaces more often than to others. In some cases, they must be recoated every year. Surfaces subject to heavy-duty use like decks should also be recoated more frequently.

You should apply a new coating to your deck in late summer. Wear and exposure to the elements are most intense in summer. So apply a new coating toward the end of that season. This will also help protect your deck from the excess moisture of fall rain and winter snow. Moisture is a key factor in wear and tear and regular recoating will extend the life of your deck.

Clean surfaces every spring (April or May) and in late summer (August or September). Clean more often if necessary. Here is how to clean your deck.

Cleaning exterior surfaces:

Checklist

  • Bucket
  • Water
  • Garden or insecticide sprayer
  • High-pressure washer
  • Scouring sponge or stiff bristled brush
  • Rubber boots and gloves
  • Protective goggles
  • Hose and nozzle
  • Polyprep Cleaner with active oxygen 771-135 (liquid) or 771-136 (powder)
  1. Rinse with clean water to moisten wood.
  2. Mix 60 grams of cleaner in 1 litre of water, then apply solution with a garden sprayer.
  3. Let work 15 to 20 minutes. Brush surface with a sponge or stiff bristled brush as it works to remove dirt and stains due to ageing. Do not let solution dry.
  4. Rinse surface with a power washer using clean water. Make sure pressure is not greater than 3400 kPa (500 lbs./sq. in.) to avoid damaging surface. Keep spray nozzle within 30 cm (1 foot) or less of surface for effective treatment.
  5. Let surface dry 2 to 3 dry, sunny days before painting. Make sure moisture content is less than 12%.
  6. If you want to roughen surface first, sand with 150-180-grade sandpaper.


After cleaning surfaces, check their condition. If they show signs of wear and tear (whitening, loss of adhesion, cracking or peeling), prepare as described in the “Preparing Surfaces and Premises” section. Check paint adhesion as follows:

Checking adhesion of coating:

  • Place 2 or 3 inches of transparent tape on coating and pull it off quickly.
  • If the coating comes up, prepare surfaces as described in the “Preparing Surfaces and Premises” section.
  • If surface is in good shape, proceed as described in the manufacturer’s instructions for the coating.