When Does Composite Decking Make More Sense Than Wood in Western Washington?

When a deck starts rotting, homeowners usually jump straight to the material question: should the replacement be cedar, pressure-treated wood, or composite? I would answer a different question first. Is the structure underneath still good enough to keep?

I’m Mark Kovalevich, co-founder of GotRot and a third-generation carpenter. We repair and rebuild decks throughout Greater Seattle, and most full replacements we see start with older wood decking. Before I recommend any new surface, I want to know what condition the ledger, joists, beams, posts, footings, stairs, and railing are in. A new composite board will not correct a weak ledger connection or rotted framing underneath it.

That is also why one soft board does not tell you whether you need a small repair or a full rebuild. Sometimes the deterioration is localized. Other times, removing the surface exposes damage that has already spread into the supporting structure.

The Surface Should Be the Last Thing You Choose

A homeowner may notice one board that feels soft, a stair that moves, or a railing that has become loose. Those are reasons to limit use of that area, but they do not tell you how far the problem goes.

We start with the visible deck and accessible structural components. If the damage has a clear boundary and the connected framing is still sound, a localized repair may make sense. If decay has reached several joists, beams, posts, or other load-bearing components, the project starts moving toward reconstruction.

There are also situations where we cannot determine the full scope without opening the structure. GotRot currently charges $950 for a destructive inspection when we need to remove material to examine concealed damage. That inspection is separate from the initial visual estimate because once we start opening the deck, we are trying to answer a different question: what can safely remain, and what actually has to be replaced?

Western Washington makes this especially important because exterior wood gets repeated exposure to rain and long damp periods. Water can enter at the deck surface, around a ledger, through failed flashing, or anywhere the structure does not drain correctly. The top of a board may look dry while its end grain or the framing below stays wet.

For new framing, we use exterior-rated pressure-treated lumber regardless of whether the finished surface will be wood, composite, or PVC. We also pay close attention to the ledger connection, flashing, footings, brackets, and drainage because the finished board is only one part of the deck.

Cedar Gives You Natural Wood, But You Have to Keep Maintaining It

Cedar is still attractive for the same reason people choose cedar siding. It is real wood, and the grain and color have a character manufactured boards do not completely reproduce. We can build a cedar deck when that is what the homeowner wants.

The tradeoff is upkeep. In our climate, cedar needs regular inspection and recurring finish care. Depending on exposure and the coating, that may mean staining or painting on an ongoing basis. The other issue is that finishing an installed board does not necessarily protect every face, cut end, or connection. Those are often the places where moisture keeps working on the wood.

Pressure-treated decking resists decay better than untreated lumber, but it still weathers and can crack, splinter, or deteriorate when moisture stays trapped. Premium hardwoods such as ipe are another category altogether. Some are extremely durable, but they come with their own fastening, finishing, and installation requirements.

This is why I usually recommend TimberTech composite or PVC for the walking surface when a homeowner wants to reduce future maintenance. We go into the differences between cedar, pressure-treated wood, hardwoods, composite, and PVC in more detail in our full guide to wood vs. composite decking.

Composite Is Easier to Live With, But It Still Has to Be Installed Correctly

Composite is usually our first recommendation for the finished deck surface because homeowners do not have to keep staining or painting it the way they would with cedar. Routine cleaning is still necessary, and the exact care depends on the product, but the maintenance burden is much lower.

We prefer TimberTech based on our field experience. For railings, we usually recommend aluminum or steel rather than wood for the same reason: there is less exposed material that needs recurring finish work.

Composite still has trade-offs. The one we explain most often is expansion and contraction. These boards move as temperatures change, so tight miters and end joints can show larger seasonal gaps. That movement does not automatically mean the deck was installed incorrectly. It means spacing and fastening have to follow the requirements for the specific product.

Drainage still matters too. A composite surface does not protect wet framing below it, and it does not fix failed flashing where the deck connects to the house. The whole structure still needs a proper path for water to move away.

That is why I do not describe composite as maintenance-free. I describe it as lower maintenance. You still want to clean it, look at connections, watch the railing, and pay attention if something starts moving differently.

A Cheaper Surface Does Not Always Mean a Cheaper Deck

For a basic 10×10-foot deck, our October 2026 planning range was approximately $10,000 to $18,000, depending on the materials and construction details. That example assumes basic decking and railing, but it is not a fixed wood price or a fixed composite price. The complete cost can change because of elevation, stairs, railing, demolition, disposal, access, footings, structural repairs, flashing, and the condition of the connection to the house. Two decks with the same square footage can have completely different scopes. That is why I would not compare cedar and composite by board price alone. Wood may cost less upfront, but recurring staining or painting continues after installation. Composite usually costs more at the beginning but asks for much less finish maintenance later. More importantly, the surface may not be the biggest cost at all. If we remove the decking and find that the joists, beams, posts, or ledger need replacement, that structural work becomes the bigger part of the project.

One Woodinville Deck Shows Why the Structure Comes First

We had a project in Woodinville where a homeowner named Fan called after a rotted cedar board broke in an area regularly used by her young children. The deck was nearly 40 years old and covered about 870 square feet.

Once we evaluated it, we found unstable boards, deteriorating beams, and an aging structure that supported full replacement rather than simply installing new boards over the existing frame. Our team removed the old decking, framing, stairs, fascia, railing, and support system. We then built approximately 960 square feet of new structure using TimberTech composite decking, hidden fasteners, and a two-tone picture-frame border. The scope included new concrete footings, posts, beams, ledger work, joists, stairs, fascia, joist tape, Z-flashing, and black Trex Select aluminum railing.

The work ran from April 28 through May 27, 2026, with final completion on May 28. The final cost was $68,468.80, and the project carries our 24-month workmanship warranty. That number is not a standard deck-replacement price because this was a complete rebuild with a large footprint and extensive structural work.

The important part is that we did not start by choosing composite. We started by figuring out whether the existing structure was worth keeping. Once the answer was no, the homeowner could make the material decision knowing the new surface would be installed over a new structure rather than covering old problems. That is generally how I approach wood versus composite. If somebody values natural cedar and understands the maintenance, we can build it. If they want a deck that requires less ongoing finish work, I usually recommend composite. But before we talk about color or brand, I want to know whether the structure underneath is sound.

Homeowners dealing with soft deck boards, failing framing, or an older deck that may need reconstruction can see more of our deck repair and exterior work at GotRot.

Mark Kovalevich Explains Why He Usually Recommends Composite Decking

The Stone Magazine (TSM): Mark, why do you usually recommend composite instead of cedar?

Mark Kovalevich (MK): Mainly maintenance. Cedar looks good, but you have to keep maintaining it. Composite does not need that same staining or painting cycle, which is a big advantage in Western Washington.

TSM: Does that mean cedar is a bad decking material?

MK: No. If a homeowner wants cedar and understands the maintenance, we can install cedar. I just want them to know what comes with it before they make the decision.

TSM: Can someone remove old cedar boards and install composite over the existing frame?

MK: Sometimes. We have to inspect the frame first. If the joists, beams, ledger, posts, and connections are sound, we may be able to keep some of it. If the framing is rotted or structurally inadequate, composite boards do not solve that.

TSM: What is the biggest issue homeowners notice with composite?

MK: Expansion and contraction. The boards move with temperature, so you can see gaps change at joints and miters. That is normal to a point, and you have to install the product with the correct spacing.

TSM: Why do you prefer TimberTech?

MK: Based on what we have worked with, we like the quality, and we also like their railing options. We still look at the specific product line because composite and PVC are not all the same.

TSM: Do you recommend composite railing too?

MK: We usually recommend aluminum or steel railing. We are trying to reduce the maintenance around the whole deck, not only the walking surface.

TSM: How do you know whether one rotten board is just one rotten board?

MK: You inspect what is connected to it. Sometimes it is localized. Sometimes you remove the surface and find damage below. That is why I do not want somebody covering a bad area before we know where the damage ends.

TSM: What do you use for new framing under composite?

MK: Exterior-rated pressure-treated lumber. The finished surface can be composite or PVC, but the framing still has to be built correctly, with the right support, flashing, and connections.

TSM: Is composite really maintenance-free?

MK: No. It is low maintenance. You still clean it, inspect it, and make sure nothing is loose or changing. You just do not have the same recurring staining and painting you get with cedar.

TSM: What should a homeowner decide first when replacing an old deck?

MK: Figure out what structure can stay. Once you know that, then it makes sense to talk about what material you want on top.