Sealing, Staining or Painting
For living, growing wood, water is life. But once the wood is used in construction, water becomes destructive. Therefore, wood must be protected.
If your deck is coated with sealer or stain, check it annually to see if it still repels water. Sprinkle some drops of water on the surface. If they are absorbed, your wood is at risk. If the water beads up and remains on the surface, you are well-protected.
With painted decks, it is important to re-coat before the paint begins to fail. Otherwise, the work (and expense) of repainting will be greater.
To give credit where credit is due… Thanks to Fitzpatrick Painting in Oregon.