Protect outdoor wood from the elements

Whether you live in Cape Town or Polokwane, wood outdoor furniture, exterior timber trim and fittings, need to be protected from constant exposure to rain and sun. Here's a look at the various options for finishing exterior wood.


All outdoor timber or wood needs protection from the elements unless you are wanting to let timber age naturally. But unprotected wood will soon succumb to mildew, or rot, and will have to be replaced. While all outdoor finishes eventually break down and need to be renewed, there are products that can be used to enhance and protect exterior wood that are better than others.


Those wanting to paint exterior wood can do so, but it is essential to use a paint product that is specifically formulated for exterior use on timber or wood.

Prominent UltraSatin is UV resistant and does not chalk on outside exposure. However, normal fading of colours can take place over time and this is easily remedied with a light sanding and application of a new coat of paint. This paint is also water vapour permeable, which allows moisture to escape while blocking ingress of water into the coating. Use Prominent UltraSatin to match fittings and fixtures to your home exterior.


There are a variety of exterior varnishes on the market but these are not generally great for outdoor timber or wood. It is important to remember that wood continuously expands and contracts in line with ambient conditions. When it is dry the cells in wood shrink and cause wood the contract, while in humid or wet weather these cell will expand. Varnish is a static product that sits on top of the timber or wood and, as such is not absorbed into the wood to form a solid, flexible bond.

If you prefer to apply an exterior varnish product, follow the manufacturer's recommended guidelines for proper application. Should signs of cracks or peeling occur, sand back and re-apply as and when required.


Sealer is an all-round enhancer and protector for timber and wood finishes. The runny consistency allows the product to be absorbed deeply into the cellular structure, as is the case with oils and penetrating waxes, which means that unlike varnish that sits on top, sealer is built up from within the wood to offer maximum protection for the longest period of time. Plus, sealers are available in a variety of tints and gloss levels to enhance and bring out the natural beauty of wood.

And for those who prefer not to use a solvent-based product, Woodoc now have a water-bourne deck sealer. Not to be confused with water-based sealer, this product uses water as a carrier for the proprietary resin that preserves and protects exterior timber and wood finishes and furniture, as well as for maintaining a beautiful deck.

Visit to see the full range of exterior products. Select an exterior sealer based on your region, since they have sealers that offer additional protection from salt spray for those in coastal areas.

Penetrating Oils and Waxes

Oils have been a popular choice for exterior timber and wood for hundreds of years. Most penetrating oils, such as Tung and Linseed, offer excellent protection when applied on a regular basis. Solvent-based penetrating waxes are considered an affordable and easily obtainable method for annual maintenance. Penetrating oils are absorbed deeply into the wood, filling up the cells in the wood, protecting from the inside out.

Applying the Finish

With oil, penetrating waxes and sealer a heavy first coat. The best method for application is with a varnish or paintbrush. The goal is to apply a liberal first coat to all parts of the project. If, before 5 minutes, the first coat has been soaked up and the surface is no longer wet, more product should be applied. You want enough product to be absorbed deeply into the cells of the wood. The endgrain will suck up the oil like a sponge, so inspect every few minutes and brush on additional product until the surface stays slightly wet.

For sealer additional coats are required, but for oils you should apply a second coat.

Note that no finish will last forever outside and you will need to re-apply the finish every 12 to 18 months in order to ensure a high level of protection.

Visit the paint section at your local Builders to view the various options available for timber and wood.