Wood or Plastic?

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When it comes to Decks . . .
Wood or Plastic? That is the Question.

Spring is the start of Deck Season – both for building and using. Those first sunny, warm days cry out to us to leave the windows open or, better yet, get outdoors and soak it in!

Even better, Bug Season hasn’t started yet. A deck, you say? What’s not to like?

Now that we’ve convinced you to build your deck, let’s talk about what materials to use. That answer, of course, is “That depends.” The major considerations are:

Location
Looks
Rigidity
Durability
Rot resistance
Ease of maintenance
Price
Environmental concerns

The Basic Decking Materials: Wood and Plastic

There are two basics types of material suitable for decking now: wood and plastic. We can break this down further into three types of wood – pressure-treated, redwood/cedar, and tropical hardwood – and two types of plastic lumber – solid plastic decking and composite decking. Each has advantages over the others.

Pressure-Treated Wood (PTW)
The big advantage here is price: PTW is less expensive than any of the other materials. It’s also readily available anywhere (though some dealers will have more grades than others). Contracts all know how to work with it, too, and are aware of its main disadvantage: it is made from softwood and is more susceptible to cupping, checking, warping, twisting, and so on.

pressure treated wood deck

We covered PTW in general in an article last spring (https://home-partners.com/articles/pressure-treated-wood). For decks in particular, PTW is the best product to use for the underpinnings: the posts and joists. The other materials either aren’t sturdy enough or they’re much too expensive.

PTW isn’t beautiful, but it can be finished in a variety of ways. At the very least, it should be power-washed yearly to remove grime and stains. Staining it every three years will help stave off decay.

Redwood and Cedar Decking
These two woods are naturally rot resistant. They’re also far less susceptible to checking, twisting, etc. than treated wood and are easy to work with. They are very good looking, even if left to age without finishing – they fade to a lovely silver gray. They should be washed each year, and a clear, penetrating sealant will maintain their natural color and also help stave off decay.

redwood deck   Cedar Deck

 

They have only two advantages, really: Both of them are expensive compared to pressure-treated wood, and they are more expensive, particularly here in New England. To some, they also present a sustainability problem. Redwood in particular does not grow quickly.

Tropical Hardwoods
Teak was the first tropical hardwood to be recognized as a wonderful outdoor building material. It has been used for decking and trim on ships for centuries. In recent years, a number of other tropical hardwoods have come to the market, offering different colors and grains with the same durability.

teak deck

These are the premier woods. They are very resistant to decay, mildew, and stains. They are very tough. They are very good looking. And they are very easy to maintain: an occasional cleaning and maybe a coating of clear, penetrating sealant. (Make sure you get a type recommended for hardwoods, or it won’t soak in properly.)

Exotic hardwoods do have a downside: They are very expensive compared to the other woods and are even more expensive than plastic decking. This is for two reasons – the wood itself is expensive, and they are harder to install because the wood is so tough.

You also want to make sure that the wood is sustainably harvested, so make sure it has been certified by the Forest Stewardship Council (https://us.fsc.org).

Plastic Decking
Plastic decking will last for years without any treatment except the occasional cleaning. Color choices can be limited, and the colors will fade with time, particularly if the location provides a lot more sun than shade. On the plus side, it is possible to paint plastics (like vinyl, which we discuss in this article last year https://home-partners.com/articles/paint-material-wood), and they are very resistant to staining.

Plastic deck

Lots of brands are made with part or all recycled plastic, which makes them environmentally friendly. The disadvantages lie in price and heat. The best plastic decking is more expensive to install than all materials except tropical hardwoods. The material alone is comparable to the price of redwood but, like the hardwoods, you must predrill and screw down plastic decking rather than nail it. In addition, plastic decking is not as rigid as wood. That means your underpinnings have to be sturdier and spaced more closely together.

Finally, there is the issue of location. If the deck gets a lot of sun, it will heat up, and plastic really soaks up the heat. On a hot, sunny day, a plastic deck can easily become painful to walk on.

Composite Decking
Composite decking is made up of a mix of sawdust (usually hardwood) and recycled plastic. Like plastic decking, it is durable and very resistant to decay, insects, stains, and mildew. It is very low maintenance. It comes in different colors, and it can be covered in a thin layer of decorative plastic to mimic wood grain.

large-composite-deck

It also has the disadvantages of plastic decking. It needs more underpinnings, gets very hot in the sunlight, and costs more than all the other materials except tropical hardwoods.

Summing Up
Most decks are made from wood of one type or another, but more and more people are choosing plastics. The choice is yours, in consultation with your contractor. Although we haven’t given you a simple yes/no answer, you should have enough information now to be able to choose the material that best suits your situation.

The important thing is to get that deck built, so you can get out there and enjoy it!

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