If you've stained your deck in the past, then the chances are you'll need to restain it at some point. While stains do a good job of protecting your deck's wood, they don't last forever.
How can you tell if your deck needs a new stain now?
1. You Can See Bare Patches
Coats of stain should look even; they should cover all the wood on your deck. As time passes, however, you might start to notice bare spots and patches here and there where the stain has worn away.
So, for example, you might see spots where it looks like a layer has peeled away. In some cases, you'll see patches of bare wood with no staining on them at all.
These signs tell you that your original stain is degrading. If it isn't giving you complete coverage, then it can't protect its wood. To avoid problems, you should look at giving the wood a recoat.
2. Your Deck Isn't Waterproof
A good wood stain contains sealants that stop water and moisture from getting into the wood on your deck. This waterproofing is vital to preventing the wood from rotting or going moldy.
However, as stains age, they might lose some of this protective quality. They might look OK, but they don't work as well as they used to.
If you suspect that your stain isn't repelling water as it should, then try a water test. Drop some water on various points on your deck and wait a while.
The water should form into droplets and sit on top of the wood. If the wood absorbs the water, either immediately or after a while, then your decking has no water protection. Now is the time to restain the deck. If your wood looks good cosmetically, then you can simply seal it as an alternative.
3. You Can See Wood Damage
If your stain has a problem, then you might see signs of wood damage. For example, areas of rot tell you that the wood hasn't always had good sealant coverage. This rot needs to be dealt with before it spreads. Wood that feels soft or that has started to splinter also needs work.
If you have wood damage, then you might need to repair or replace some of the decking before you restain it. There isn't much point just covering over damaged areas.
If you aren't sure if your deck needs restaining, or if you want professional help with this job, then contact a local deck staining service.