Composite Decking Pros and Cons

Composite decking planks look like real wood.

If you're considering having a deck built of composite materials, it helps to have an idea of the composite decking pros and cons to ensure you know exactly what to expect.

What is Composite Decking?

Enter any home improvement store, and near the lumber section you will see planks that resemble wood but feature a label identifying the planks as "composite." While they are manufactured to mimic the look and feel of real wood, composite decking materials are made mostly from synthetics.

Composite decking boards and railing systems virtually eliminate the annual maintenance needs of a wooden deck, because they contain little to no natural products. It's important to note, however, that composite decking materials are only used on the top or the finished area of the deck. The framing and support joists are still made using traditional wood.

The Pros and Cons of Composite Decking

Pros of Composite Decking

  • The maintenance requirements for a composite deck couldn't be easier. To maintain the decking, sweep away any debris or hose the deck off with some clean water.
  • Composite materials will not bulge, warp, split or crack after exposure to the elements.
  • No special tools are needed to install composite decking.
  • Composite decking comes in a wide range of colors and some companies can customize the boards so they match perfectly with your home's exterior.
  • The color of the composite boards lasts much longer than traditional wood stain or paint.
  • Many companies use recycled materials in the manufacturing of their composite decking, which will make your deck more environmentally friendly.

Cons of Composite Decking

  • The biggest drawback of composite decking materials is cost. Decks built using this newer technology typically cost two to five times more than decks constructed with pressure-treated wood.
  • Composite decking planks are also much heavier than identically sized wood planks.
  • Special fasteners are usually required.
  • While composite materials won't crack or splinter, extreme heat can cause some materials to become more flexible.

Composite Controversy

Composite decking materials were first introduced in the early 1990s, and the product was considered a marvel in the construction industry. Originally manufactured using recycled milk cartons and shipping pallets, these materials were heralded to be 100 percent resistant to rot, although scientific articles published in the Forest Products Journal in 2001 and 2002 proved otherwise. In the white papers, tests results indicated that composite decking will eventually rot if it isn't treated first with a preservative.

Modern composite decking materials have come a long way, as many companies now use virgin plastic and cellulose fibers or a combination of these materials with natural or recycled products in their decking planks and accessories. It's important to note that unless the composite materials have been treated with preservatives, they are still prone to rot over time.

The most important thing to look for in composite decking is whether or not the materials have been treated with a preservative. The most common preservative used to protect composite materials is zinc borate; a chemical that's poisonous to many of the fungi responsible for wood rot.

Composite Decking Warranties

Before making a purchase, ask for proof of the preservative from the manufacturer and get it in writing, even if the manufacturer provides a warranty with their product.

It's also very important to follow the installation instructions perfectly when installing composite decking. Incorrect plank spacing or support joist placement can void the manufacturer's warranty.

Is a Composite Deck for You?

It can be very tempting to fall under the spell of composite decking, but it really pays to weigh the difference between the composite decking pros and cons in order to come to an educated decision. There certainly are some great things about using composite decking materials, but cost and preservative issues can be a deterrent. Do your research and contact the manufacturer before making your decision on what material you will use to build your deck.

Composite Decking Pros and Cons