What is weatherproofing?
In reference to a deck, weatherproofing is preventing the elements from turning your beautiful, deep-grained deck into one that's featureless and grey. All timber decks will someday lose their colour and fade to grey - what weatherproofing allows you to do is postpone this.
Weatherproofing can take many forms, from the materials you use in construction to keeping the deck regularly sealed and maintained. Though it can be a chore at times, the benefits of keeping your deck sealed against the weather are pretty clear, adding to the look of your home, your property’s value and your enjoyment of the deck.
Why is weatherproofing important?
The Australian climate is a harsh one, and if your deck isn't covered it will be exposed to these elements all day, every day for the rest of its useful life. Depending on what part of the country you live in, you might experience everything from blasting hot sun to wild gusts of wind to hail and rain (and if you’re in Melbourne, you're likely to see all of those in a single day). Unprotected wood will quickly lose its colour and turn grey through sun bleaching and water damage. Unless this is the desired effect, weatherproofing's a good idea.
What can be done to weatherproof a deck?
Weatherproofing should be an ongoing concern right from the planning phase. Keeping your deck sheltered against the sun and rain will help cut down on maintenance, but may not always be feasible. If your heart's set on an unshaded, freestanding deck to sunbathe on, then this isn't going to be an option.
Using weatherproofed fittings is a must - use a minimum of hot-dip galvanised steel to prevent corrosion and stainless steel if you anticipate regular water contact such as near a pool or spa. Your boards, bearers, joists and beams should all be waterproofed before installation to ensure an even coating is applied to all sides, and any exposed ends from cutting or drilling should be sealed as well. You may consider laying down some sort of continuous membrane under the boards to shield the bearers and joists from water exposure. You should also recoat the deck with your choice of sealant whenever it’s required (at least once a year is ideal); there’s no point to going to all the effort of making sure your deck is weatherproof only to have it all turn grey after a year or so.
How to different weatherproofing treatments compare?
Different sealants can be used to treat your deck and offer different benefits.
- Decking oils won’t change the colour of your deck, and will enrich the natural tones and moistures of the wood, bringing a lustrous glow and sealing it against water. However, deck oils don’t offer much in the way of UV protection and will need to be reapplied more often than other treatments.
- Wood stains come in a variety of shades from solid to translucent and provide both good water and UV shielding (darker and more solid stains will block more UV) which will slow any damage from occurring. Wood stains can penetrate deep into the wood to offer long lasting protection. Over time though, stains can accumulate in the wood and darken it, stopping any features of the grain from showing through. The wood can be sanded back and re-stained to restore the finish, but this is obviously a bit more work.
- Acrylic sealants don’t penetrate into the wood at all; they form a film over the top of it to provide a weatherproof coating. This can be especially useful in constantly wet areas such as next to a pool where it's useful for the water to run right off the top of the wood. Because these sealants sit on the surface though, they are more prone to flaking and lifting. If that happens, the deck may need re-sanding and sealing.
