The Best Decking Material for Seattle and the Pacific Northwest Is Gorgeous and Rain Friendly

Composite decking, the best decking material for seattle

New, high-quality composite decking plays well with the rain, even in places like Seattle and the Pacific Northwest.

More than half of my career has been spent working in the Pacific Northwest. When it rains for nearly 9 months continuously, the dry respite of summer pulls everyone outdoors onto porches, decks, and patios. Since rain and humidity can be so punishing to a deck, my clients typically hire me to do lots of cleanup and maintenance during the drier seasons, in addition to deck installation.

However, wood decking in the Pacific NW isn’t always the best choice, and, looking for ways to give my clients more value, I’ve done a lot of experimenting with materials to find one that would allow my clients in places like Seattle and Portland to have a long-lasting, beautiful deck with very little regular maintenance. Pacific Northwesterners want to take full advantage of the short dry period they have, so they need a deck that can survive months of rain, clean up easily, and ideally, look beautiful no matter what weather it experienced over the winter. We’ll be exploring what characteristics a deck needs to have to survive well in states like Washington and Oregon, and what is the best decking material for Seattle and the Pacific Northwest.

Finding Materials That Will Survive Months of Rain

It goes without saying that the levels of precipitation out in the Pacific NW area are truly epic and downright depressing sometimes. While most people can take shelter from the continuous fall of the rain, decks and outdoor structures don’t have that luxury. Understanding why rain causes such a problem for decks and what needs to be done to prevent damage by rain can help when it comes to choosing a decking material.

  • Moisture Infiltrates and Deteriorates Boards: Water will always find the lowest level and the path of least resistance. That means that horizontal surfaces like decking boards are especially vulnerable to water erosion and penetration. Unprotected wood will soak up water like a sponge, channeling the moisture through the board’s paths of least resistance until it pools, saturates, and expands the wood. This action, paired with periods of drying out in the sun, leads to cracks and warping in the wood or decking material. It can also lead to swelling and shrinking that forces nails and screws out of the decking boards.
  • Different Materials Require Different Methods: The two main choices in decking out there right now are wood and composite. Both types of decking material need to be protected from extended heavy rain. Here’s how.
    • Wood: Whether it’s cedar decking or Brazilian ipe, wood decks require a sealer or an oil that forms a thick enough layer to repel water. Some sealers are more durable and long lasting than others. On average, though, most decks could use a reapplication of sealer about every two years. In the Pacific Northwest, this is usually sufficient, but doing it once a year is usually even better.
    • Composite Decking: For a while, composite was not a good choice in my area. In the first generations of composite decking, water would find its way into the board (made of a combination of plastic and sawdust) and travel along seams of sawdust, leading to the same kind of deterioration experienced by wood. These boards tended to swell, chip, crumble, and mold. In short order, though, composites underwent a revolution. Most now have a full cap–a tough waterproof coating that completely encases the composite board below. If using composite decking, I always advise getting boards with this kind of protection. And even fully capped decking isn’t all the same. Some composites are being made with a combination of plastic and bamboo flour, rather than sawdust, which makes the core of the boards much more moisture resistant than typical composites.

The Best Decking Material for Seattle and the Pacific Northwest

After the challenge of moisture is addressed, there are a couple qualities in decking material that make life far easier for those with Seattle and NW decks. Reasonably easy clean-up and actually looking beautiful are major boxes that most of us want checked.

  • Easy Cleanup to Enjoy the Dry Months: When spring and summer do arrive, Seattleites want their decks to be usable with as little fussing with cleanup as possible. While cleanup requirements will differ from location to location, wood and composite have pretty consistent needs when it comes to getting them ready to go for the season.
  • Wood: When the seal is strong and fresh, wooden decking cleans up very easily. Once the protection wears down, though, the porous surface of the wood attracts dirt, mold, and mildew. Cleanup usually means pressure washing, perhaps some sanding, and then a reapplication of sealer.
  • Composite: Cleanup of composite decking is typically as easy as a vigorous mopping session or a quick hosing off. Since the capping isn’t as porous as wood is, dirt and other detritus don’t collect as easily, and mold and mildew are rare and easy to rinse off.
  • A Combination of Style and Durability: High-quality composite does very well in rainy climates, but, of course, all the functionality and durability in the world don’t matter if the material is ugly. Many of my friends and clients have no problem with the care and maintenance involved in keeping an ipe deck in tip-top shape, because they’re willing to work when it comes to a beautiful material. Those friends–and I–objected to the composite decking of the past due to its aesthetic shortfalls. Now, while ipe and cedar are still undeniably attractive materials, there is composite decking that looks like wood, including composite that uncannily resembles ipe and other hardwoods, but without the maintenance load.

I’ve put in dozens of decks in the Pacific Northwest, particularly around Seattle, and I’ve maintained and repaired even more. As my skills have grown, I’ve learned to accomplish more with less effort and expense. While I still install plenty of cedar and ipe decks, many of my clients want more from their decks without having to do so much. I almost always steer these clients in the direction of high-quality, fully capped composite decking.

There are a few types of composites out there, but the first product I usually suggest they consider is the bamboo composite Infinity Decking produced by Fortress Deck. It’s all the things high-quality decking should be–beautiful, realistic, tough against sun, rain, and mold, elegant, safe, and barefoot friendly. When clients’ deck projects get bigger, and require a railing or structure like a pergola, I usually suggest looking at Fortress’ full catalog of building materials. The other Fortress products I’ve looked at and worked with are just as sturdy, unique, and well made as their decking.

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