Many decks are fully or partially exposed to the weather. To preserve their structural integrity specific measures must be undertaken. Failure to take these measures greatly reduces the lifetime of a deck.
Interior timber flooring and external decking share many of the same properties, however the preparation and coating systems are very different.
Oil based coatings
Oil based deck coatings have inherent shortcomings due to the nature of oil. Decking oils do not last very long. It may be only 6 to 12 months before an oiled deck begins to look tired and in need of another coat. In addition fungal growth often occurs which results in unsightly black staining under the oil based coating.
Skin or film build oil based coatings often start to break down and will crack, peel and show white discolouration where moisture creeps underneath. The only way to remedy this is by fully re-sanding and starting the coating process again.
Oil based deck coatings are usually cheaper than water based, unfortunatly, the initial saving is a false economy.
Use of hardwood
Hardwood is the best choice for decking, correct preparation is necessary to remove natural tannins and oils from the surface of the boards. If these naturally occurring substances are not treated then the coating will not bond well to the timber.
Why many deck coatings fail
A major reason why many deck coatings fail, both oil and water based, is due to lack of preparation or insufficient and incorrect preparation. Preparation is paramount especially when timber is exposed to sun and rain together with radical temperature variations. Sometimes deck coatings fail or just do not last, due to the type of coating used.
The amount of work and cost involved with improper timber deck preparation and coating means that you are far better off in the long run using the services of an expert.