Composite vs Wood Decking in a Wet Climate: An Honest Comparison
A straight head-to-head on composite vs wood decking for the rainy Pacific Northwest: real cost, maintenance, moss and mildew, longevity, and how to pick the right one for your Clark County deck.
In the wet Pacific Northwest, neither composite nor wood is automatically better. It comes down to how you want to spend your time and money. Wood costs less upfront but needs regular cleaning, sealing, and staining to survive our rain, and it still weathers faster here. Composite costs more to install but skips the sealing and staining entirely. You just keep it clean to fight moss and mildew. Both will grow green film in shade. The honest answer for most Clark County homeowners: wood if budget is tight and you do not mind the upkeep, composite if you want to stop maintaining and just use your deck. Below is the full head-to-head.
First, the part both materials share
Whatever you walk on, the frame underneath is almost always pressure-treated lumber. The posts, beams, and joists that hold the deck up are wood treated to resist rot and insects. That structure is where the real longevity of a deck comes from. A beautiful composite surface on a failing frame is still a failing deck.
So when we talk composite vs wood decking, we are really only talking about the boards you see and touch. The bones are the same either way, and in our climate keeping water moving off that frame matters more than the surface you pick.
Upfront cost
Wood wins on day one. Pressure-treated and cedar decking boards cost less than composite, sometimes a good bit less, so a wood deck is the cheaper project to build. If the goal is the lowest number to get a usable deck this season, wood is the honest answer.
Composite costs more to buy and install. The trade is that you are paying upfront to avoid years of sealing and staining later. Whether that math works for you depends on how long you plan to stay in the home and how you feel about annual upkeep.
Maintenance in our rain
This is where the wet PNW changes the conversation. A wood deck here needs real, repeating care. Plan on cleaning it and reapplying sealer or stain on a regular cycle to keep water out of the boards. Skip it for a couple of seasons and our rain finds its way in, which leads to graying, splintering, and soft spots [1].
Composite does not need sealing, staining, or painting at any point [1]. The upkeep is cleaning. Soap, water, and a gentle wash a couple of times a year keep it looking right [1]. You are not eliminating maintenance, you are trading a weekend of sanding and staining for an occasional wash down.
The real question is not which deck needs zero work. It is which kind of work you are willing to keep doing every year in the rain.
Moss and mildew, honestly
Every horizontal surface in the shade here grows moss and mildew. Composite is not immune. Sit it under fir trees on the north side of the house and you will get a green film just like you would on wood. The difference is how it behaves.
- On wood, moss and mildew hold moisture against a porous, organic surface. Left alone, that trapped damp is what eventually rots the board.
- On composite, the same growth sits on top of a material that does not absorb water the way wood does, so it cleans off without feeding decay underneath.
- Both benefit from sun, airflow, and keeping leaves and debris swept off through our long wet months.
Longevity
A well-built wood deck can last a couple of decades here if you stay on top of the sealing and stay ahead of moisture. Let the upkeep slip and our climate shortens that fast. Composite is built to resist moisture, mold, and insects, and quality lines carry warranties in the 25 to 50 year range [2]. That resistance is the main reason composite outlasts wood in a place like ours [2].
Remember the shared part. Both numbers assume the pressure-treated frame underneath is sound and draining well. The surface can outlive the structure if the bones were never built or maintained right.
Appearance and feel
Wood looks and feels like wood because it is, with real grain and the option to change the color when you restain. Many homeowners simply prefer it. The catch is that the look only stays good with the upkeep behind it.
Composite gives you a consistent color and texture that holds up without refinishing. Newer boards mimic wood grain well, though up close some people can still tell. It will not give you the option to restain a different shade later, so pick a color you will be happy with for years.
So which should you choose
Here is the balanced read for a Clark County deck:
- Choose wood if budget upfront is the priority, you genuinely do not mind a yearly clean-and-seal routine, or you want the real-wood look and the freedom to change the color down the road.
- Choose composite if you would rather stop maintaining the surface and just use the deck, you plan to stay in the home long enough to earn back the higher upfront cost, or your deck sits in heavy shade where wood struggles most.
There is no wrong answer. It is a trade between money now and time later, judged against your own deck, your shade, and how you actually live outside. Either way, the work starts with a sound, well-draining frame, because that is what carries the deck through our winters.
Not sure which way to go for your deck and budget? We will walk your deck, look at the frame and the drainage, and talk through composite or wood honestly for your spot in Clark County. Call (360) 838-6731 or reach out and we will help you pick the right material, not the most expensive one. See Deck Restoration